text: // This is an open source non-commercial project. Dear PVS-Studio, please check
  // it. PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
  
  //
  // normal.c:    Contains the main routine for processing characters in command
  //              mode.  Communicates closely with the code in ops.c to handle
  //              the operators.
  //
  
  #include <assert.h>
  #include <inttypes.h>
  #include <stdbool.h>
  #include <stdlib.h>
  #include <string.h>
  
  #include "nvim/api/private/helpers.h"
  #include "nvim/ascii.h"
  #include "nvim/buffer.h"
  #include "nvim/change.h"
  #include "nvim/charset.h"
  #include "nvim/cursor.h"
  #include "nvim/diff.h"
  #include "nvim/digraph.h"
  #include "nvim/edit.h"
  #include "nvim/eval/userfunc.h"
  #include "nvim/event/loop.h"
  #include "nvim/ex_cmds.h"
  #include "nvim/ex_cmds2.h"
  #include "nvim/ex_docmd.h"
  #include "nvim/ex_getln.h"
  #include "nvim/fileio.h"
  #include "nvim/fold.h"
  #include "nvim/getchar.h"
  #include "nvim/indent.h"
  #include "nvim/indent_c.h"
  #include "nvim/keymap.h"
  #include "nvim/log.h"
  #include "nvim/main.h"
  #include "nvim/mark.h"
  #include "nvim/memline.h"
  #include "nvim/memory.h"
  #include "nvim/message.h"
  #include "nvim/misc1.h"
  #include "nvim/mouse.h"
  #include "nvim/move.h"
  #include "nvim/normal.h"
  #include "nvim/ops.h"
  #include "nvim/option.h"
  #include "nvim/os/input.h"
  #include "nvim/os/time.h"
  #include "nvim/plines.h"
  #include "nvim/quickfix.h"
  #include "nvim/screen.h"
  #include "nvim/search.h"
  #include "nvim/spell.h"
  #include "nvim/spellfile.h"
  #include "nvim/state.h"
  #include "nvim/strings.h"
  #include "nvim/syntax.h"
  #include "nvim/tag.h"
  #include "nvim/ui.h"
  #include "nvim/undo.h"
  #include "nvim/vim.h"
  #include "nvim/window.h"
  
  typedef struct normal_state {
    VimState state;
    bool command_finished;
    bool ctrl_w;
    bool need_flushbuf;
    bool set_prevcount;
    bool previous_got_int;             // `got_int` was true
    bool cmdwin;                       // command-line window normal mode
    bool noexmode;                     // true if the normal mode was pushed from
                                       // ex mode(:global or :visual for example)
    bool toplevel;                     // top-level normal mode
    oparg_T oa;                        // operator arguments
    cmdarg_T ca;                       // command arguments
    int mapped_len;
    int old_mapped_len;
    int idx;
    int c;
    int old_col;
    pos_T old_pos;
  } NormalState;
  
  /*
   * The Visual area is remembered for reselection.
   */
  static int resel_VIsual_mode = NUL;             // 'v', 'V', or Ctrl-V
  static linenr_T resel_VIsual_line_count;        // number of lines
  static colnr_T resel_VIsual_vcol;               // nr of cols or end col
  static int VIsual_mode_orig = NUL;              // saved Visual mode
  
  
  #ifdef INCLUDE_GENERATED_DECLARATIONS
  # include "normal.c.generated.h"
  #endif
  
  static inline void normal_state_init(NormalState *s)
  {
    memset(s, 0, sizeof(NormalState));
    s->state.check = normal_check;
    s->state.execute = normal_execute;
  }
  
  /*
   * nv_*(): functions called to handle Normal and Visual mode commands.
   * n_*(): functions called to handle Normal mode commands.
   * v_*(): functions called to handle Visual mode commands.
   */
  
  static char *e_noident = N_("E349: No identifier under cursor");
  
  /*
   * Function to be called for a Normal or Visual mode command.
   * The argument is a cmdarg_T.
   */
  typedef void (*nv_func_T)(cmdarg_T *cap);
  
  // Values for cmd_flags.
  #define NV_NCH      0x01          // may need to get a second char
  #define NV_NCH_NOP  (0x02|NV_NCH)  // get second char when no operator pending
  #define NV_NCH_ALW  (0x04|NV_NCH)  // always get a second char
  #define NV_LANG     0x08        // second char needs language adjustment
  
  #define NV_SS       0x10        // may start selection
  #define NV_SSS      0x20        // may start selection with shift modifier
  #define NV_STS      0x40        // may stop selection without shift modif.
  #define NV_RL       0x80        // 'rightleft' modifies command
  #define NV_KEEPREG  0x100       // don't clear regname
  #define NV_NCW      0x200       // not allowed in command-line window
  
  /*
   * Generally speaking, every Normal mode command should either clear any
   * pending operator (with *clearop*()), or set the motion type variable
   * oap->motion_type.
   *
   * When a cursor motion command is made, it is marked as being a character or
   * line oriented motion.  Then, if an operator is in effect, the operation
   * becomes character or line oriented accordingly.
   */
  
  /*
   * This table contains one entry for every Normal or Visual mode command.
   * The order doesn't matter, init_normal_cmds() will create a sorted index.
   * It is faster when all keys from zero to '~' are present.
   */
  static const struct nv_cmd {
    int cmd_char;                 // (first) command character
    nv_func_T cmd_func;           // function for this command
    uint16_t cmd_flags;           // NV_ flags
    short cmd_arg;                // value for ca.arg
  } nv_cmds[] =
  {
    { NUL,       nv_error,       0,                      0 },
    { Ctrl_A,    nv_addsub,      0,                      0 },
    { Ctrl_B,    nv_page,        NV_STS,                 BACKWARD },
    { Ctrl_C,    nv_esc,         0,                      true },
    { Ctrl_D,    nv_halfpage,    0,                      0 },
    { Ctrl_E,    nv_scroll_line, 0,                      true },
    { Ctrl_F,    nv_page,        NV_STS,                 FORWARD },
    { Ctrl_G,    nv_ctrlg,       0,                      0 },
    { Ctrl_H,    nv_ctrlh,       0,                      0 },
    { Ctrl_I,    nv_pcmark,      0,                      0 },
    { NL,        nv_down,        0,                      false },
    { Ctrl_K,    nv_error,       0,                      0 },
    { Ctrl_L,    nv_clear,       0,                      0 },
    { CAR,       nv_down,        0,                      true },
    { Ctrl_N,    nv_down,        NV_STS,                 false },
    { Ctrl_O,    nv_ctrlo,       0,                      0 },
    { Ctrl_P,    nv_up,          NV_STS,                 false },
    { Ctrl_Q,    nv_visual,      0,                      false },
    { Ctrl_R,    nv_redo,        0,                      0 },
    { Ctrl_S,    nv_ignore,      0,                      0 },
    { Ctrl_T,    nv_tagpop,      NV_NCW,                 0 },
    { Ctrl_U,    nv_halfpage,    0,                      0 },
    { Ctrl_V,    nv_visual,      0,                      false },
    { 'V',       nv_visual,      0,                      false },
    { 'v',       nv_visual,      0,                      false },
    { Ctrl_W,    nv_window,      0,                      0 },
    { Ctrl_X,    nv_addsub,      0,                      0 },
    { Ctrl_Y,    nv_scroll_line, 0,                      false },
    { Ctrl_Z,    nv_suspend,     0,                      0 },
    { ESC,       nv_esc,         0,                      false },
    { Ctrl_BSL,  nv_normal,      NV_NCH_ALW,             0 },
    { Ctrl_RSB,  nv_ident,       NV_NCW,                 0 },
    { Ctrl_HAT,  nv_hat,         NV_NCW,                 0 },
    { Ctrl__,    nv_error,       0,                      0 },
    { ' ',       nv_right,       0,                      0 },
    { '!',       nv_operator,    0,                      0 },
    { '"',       nv_regname,     NV_NCH_NOP|NV_KEEPREG,  0 },
    { '#',       nv_ident,       0,                      0 },
    { '$',       nv_dollar,      0,                      0 },
    { '%',       nv_percent,     0,                      0 },
    { '&',       nv_optrans,     0,                      0 },
    { '\'',      nv_gomark,      NV_NCH_ALW,             true },
    { '(',       nv_brace,       0,                      BACKWARD },
    { ')',       nv_brace,       0,                      FORWARD },
    { '*',       nv_ident,       0,                      0 },
    { '+',       nv_down,        0,                      true },
    { ',',       nv_csearch,     0,                      true },
    { '-',       nv_up,          0,                      true },
    { '.',       nv_dot,         NV_KEEPREG,             0 },
    { '/',       nv_search,      0,                      false },
    { '0',       nv_beginline,   0,                      0 },
    { '1',       nv_ignore,      0,                      0 },
    { '2',       nv_ignore,      0,                      0 },
    { '3',       nv_ignore,      0,                      0 },
    { '4',       nv_ignore,      0,                      0 },
    { '5',       nv_ignore,      0,                      0 },
    { '6',       nv_ignore,      0,                      0 },
    { '7',       nv_ignore,      0,                      0 },
    { '8',       nv_ignore,      0,                      0 },
    { '9',       nv_ignore,      0,                      0 },
    { ':',       nv_colon,       0,                      0 },
    { ';',       nv_csearch,     0,                      false },
    { '<',       nv_operator,    NV_RL,                  0 },
    { '=',       nv_operator,    0,                      0 },
    { '>',       nv_operator,    NV_RL,                  0 },
    { '?',       nv_search,      0,                      false },
    { '@',       nv_at,          NV_NCH_NOP,             false },
    { 'A',       nv_edit,        0,                      0 },
    { 'B',       nv_bck_word,    0,                      1 },
    { 'C',       nv_abbrev,      NV_KEEPREG,             0 },
    { 'D',       nv_abbrev,      NV_KEEPREG,             0 },
    { 'E',       nv_wordcmd,     0,                      true },
    { 'F',       nv_csearch,     NV_NCH_ALW|NV_LANG,     BACKWARD },
    { 'G',       nv_goto,        0,                      true },
    { 'H',       nv_scroll,      0,                      0 },
    { 'I',       nv_edit,        0,                      0 },
    { 'J',       nv_join,        0,                      0 },
    { 'K',       nv_ident,       0,                      0 },
    { 'L',       nv_scroll,      0,                      0 },
    { 'M',       nv_scroll,      0,                      0 },
    { 'N',       nv_next,        0,                      SEARCH_REV },
    { 'O',       nv_open,        0,                      0 },
    { 'P',       nv_put,         0,                      0 },
    { 'Q',       nv_exmode,      NV_NCW,                 0 },
    { 'R',       nv_Replace,     0,                      false },
    { 'S',       nv_subst,       NV_KEEPREG,             0 },
    { 'T',       nv_csearch,     NV_NCH_ALW|NV_LANG,     BACKWARD },
    { 'U',       nv_Undo,        0,                      0 },
    { 'W',       nv_wordcmd,     0,                      true },
    { 'X',       nv_abbrev,      NV_KEEPREG,             0 },
    { 'Y',       nv_abbrev,      NV_KEEPREG,             0 },
    { 'Z',       nv_Zet,         NV_NCH_NOP|NV_NCW,      0 },
    { '[',       nv_brackets,    NV_NCH_ALW,             BACKWARD },
    { '\\',      nv_error,       0,                      0 },
    { ']',       nv_brackets,    NV_NCH_ALW,             FORWARD },
    { '^',       nv_beginline,   0,                      BL_WHITE | BL_FIX },
    { '_',       nv_lineop,      0,                      0 },
    { '`',       nv_gomark,      NV_NCH_ALW,             false },
    { 'a',       nv_edit,        NV_NCH,                 0 },
    { 'b',       nv_bck_word,    0,                      0 },
    { 'c',       nv_operator,    0,                      0 },
    { 'd',       nv_operator,    0,                      0 },
    { 'e',       nv_wordcmd,     0,                      false },
    { 'f',       nv_csearch,     NV_NCH_ALW|NV_LANG,     FORWARD },
    { 'g',       nv_g_cmd,       NV_NCH_ALW,             false },
    { 'h',       nv_left,        NV_RL,                  0 },
    { 'i',       nv_edit,        NV_NCH,                 0 },
    { 'j',       nv_down,        0,                      false },
    { 'k',       nv_up,          0,                      false },
    { 'l',       nv_right,       NV_RL,                  0 },
    { 'm',       nv_mark,        NV_NCH_NOP,             0 },
    { 'n',       nv_next,        0,                      0 },
    { 'o',       nv_open,        0,                      0 },
    { 'p',       nv_put,         0,                      0 },
    { 'q',       nv_record,      NV_NCH,                 0 },
    { 'r',       nv_replace,     NV_NCH_NOP|NV_LANG,     0 },
    { 's',       nv_subst,       NV_KEEPREG,             0 },
    { 't',       nv_csearch,     NV_NCH_ALW|NV_LANG,     FORWARD },
    { 'u',       nv_undo,        0,                      0 },
    { 'w',       nv_wordcmd,     0,                      false },
    { 'x',       nv_abbrev,      NV_KEEPREG,             0 },
    { 'y',       nv_operator,    0,                      0 },
    { 'z',       nv_zet,         NV_NCH_ALW,             0 },
    { '{',       nv_findpar,     0,                      BACKWARD },
    { '|',       nv_pipe,        0,                      0 },
    { '}',       nv_findpar,     0,                      FORWARD },
    { '~',       nv_tilde,       0,                      0 },
  
    // pound sign
    { POUND,     nv_ident,       0,                      0 },
    { K_MOUSEUP, nv_mousescroll, 0,                      MSCR_UP },
    { K_MOUSEDOWN, nv_mousescroll, 0,                    MSCR_DOWN },
    { K_MOUSELEFT, nv_mousescroll, 0,                    MSCR_LEFT },
    { K_MOUSERIGHT, nv_mousescroll, 0,                   MSCR_RIGHT },
    { K_LEFTMOUSE, nv_mouse,     0,                      0 },
    { K_LEFTMOUSE_NM, nv_mouse,  0,                      0 },
    { K_LEFTDRAG, nv_mouse,      0,                      0 },
    { K_LEFTRELEASE, nv_mouse,   0,                      0 },
    { K_LEFTRELEASE_NM, nv_mouse, 0,                     0 },
    { K_MOUSEMOVE, nv_mouse,     0,                      0 },
    { K_MIDDLEMOUSE, nv_mouse,   0,                      0 },
    { K_MIDDLEDRAG, nv_mouse,    0,                      0 },
    { K_MIDDLERELEASE, nv_mouse, 0,                      0 },
    { K_RIGHTMOUSE, nv_mouse,    0,                      0 },
    { K_RIGHTDRAG, nv_mouse,     0,                      0 },
    { K_RIGHTRELEASE, nv_mouse,  0,                      0 },
    { K_X1MOUSE, nv_mouse,       0,                      0 },
    { K_X1DRAG, nv_mouse,        0,                      0 },
    { K_X1RELEASE, nv_mouse,     0,                      0 },
    { K_X2MOUSE, nv_mouse,       0,                      0 },
    { K_X2DRAG, nv_mouse,        0,                      0 },
    { K_X2RELEASE, nv_mouse,     0,                      0 },
    { K_IGNORE,  nv_ignore,      NV_KEEPREG,             0 },
    { K_NOP,     nv_nop,         0,                      0 },
    { K_INS,     nv_edit,        0,                      0 },
    { K_KINS,    nv_edit,        0,                      0 },
    { K_BS,      nv_ctrlh,       0,                      0 },
    { K_UP,      nv_up,          NV_SSS|NV_STS,          false },
    { K_S_UP,    nv_page,        NV_SS,                  BACKWARD },
    { K_DOWN,    nv_down,        NV_SSS|NV_STS,          false },
    { K_S_DOWN,  nv_page,        NV_SS,                  FORWARD },
    { K_LEFT,    nv_left,        NV_SSS|NV_STS|NV_RL,    0 },
    { K_S_LEFT,  nv_bck_word,    NV_SS|NV_RL,            0 },
    { K_C_LEFT,  nv_bck_word,    NV_SSS|NV_RL|NV_STS,    1 },
    { K_RIGHT,   nv_right,       NV_SSS|NV_STS|NV_RL,    0 },
    { K_S_RIGHT, nv_wordcmd,     NV_SS|NV_RL,            false },
    { K_C_RIGHT, nv_wordcmd,     NV_SSS|NV_RL|NV_STS,    true },
    { K_PAGEUP,  nv_page,        NV_SSS|NV_STS,          BACKWARD },
    { K_KPAGEUP, nv_page,        NV_SSS|NV_STS,          BACKWARD },
    { K_PAGEDOWN, nv_page,       NV_SSS|NV_STS,          FORWARD },
    { K_KPAGEDOWN, nv_page,      NV_SSS|NV_STS,          FORWARD },
    { K_END,     nv_end,         NV_SSS|NV_STS,          false },
    { K_KEND,    nv_end,         NV_SSS|NV_STS,          false },
    { K_S_END,   nv_end,         NV_SS,                  false },
    { K_C_END,   nv_end,         NV_SSS|NV_STS,          true },
    { K_HOME,    nv_home,        NV_SSS|NV_STS,          0 },
    { K_KHOME,   nv_home,        NV_SSS|NV_STS,          0 },
    { K_S_HOME,  nv_home,        NV_SS,                  0 },
    { K_C_HOME,  nv_goto,        NV_SSS|NV_STS,          false },
    { K_DEL,     nv_abbrev,      0,                      0 },
    { K_KDEL,    nv_abbrev,      0,                      0 },
    { K_UNDO,    nv_kundo,       0,                      0 },
    { K_HELP,    nv_help,        NV_NCW,                 0 },
    { K_F1,      nv_help,        NV_NCW,                 0 },
    { K_XF1,     nv_help,        NV_NCW,                 0 },
    { K_SELECT,  nv_select,      0,                      0 },
    { K_EVENT,   nv_event,       NV_KEEPREG,             0 },
    { K_COMMAND, nv_colon,       0,                      0 },
  };
  
  // Number of commands in nv_cmds[].
  #define NV_CMDS_SIZE ARRAY_SIZE(nv_cmds)
  
  // Sorted index of commands in nv_cmds[].
  static short nv_cmd_idx[NV_CMDS_SIZE];
  
  // The highest index for which
  // nv_cmds[idx].cmd_char == nv_cmd_idx[nv_cmds[idx].cmd_char]
  static int nv_max_linear;
  
  /*
   * Compare functions for qsort() below, that checks the command character
   * through the index in nv_cmd_idx[].
   */
  static int nv_compare(const void *s1, const void *s2)
  {
    int c1, c2;
  
    // The commands are sorted on absolute value.
    c1 = nv_cmds[*(const short *)s1].cmd_char;
    c2 = nv_cmds[*(const short *)s2].cmd_char;
    if (c1 < 0) {
      c1 = -c1;
    }
    if (c2 < 0) {
      c2 = -c2;
    }
    return c1 - c2;
  }
  
  /*
   * Initialize the nv_cmd_idx[] table.
   */
  void init_normal_cmds(void)
  {
    assert(NV_CMDS_SIZE <= SHRT_MAX);
  
    // Fill the index table with a one to one relation.
    for (short int i = 0; i < (short int)NV_CMDS_SIZE; ++i) {
      nv_cmd_idx[i] = i;
    }
  
    // Sort the commands by the command character.
    qsort(&nv_cmd_idx, NV_CMDS_SIZE, sizeof(short), nv_compare);
  
    // Find the first entry that can't be indexed by the command character.
    short int i;
    for (i = 0; i < (short int)NV_CMDS_SIZE; ++i) {
      if (i != nv_cmds[nv_cmd_idx[i]].cmd_char) {
        break;
      }
    }
    nv_max_linear = i - 1;
  }
  
  /*
   * Search for a command in the commands table.
   * Returns -1 for invalid command.
   */
  static int find_command(int cmdchar)
  {
    int i;
    int idx;
    int top, bot;
    int c;
  
    // A multi-byte character is never a command.
    if (cmdchar >= 0x100) {
      return -1;
    }
  
    // We use the absolute value of the character.  Special keys have a
    // negative value, but are sorted on their absolute value.
    if (cmdchar < 0) {
      cmdchar = -cmdchar;
    }
  
    // If the character is in the first part: The character is the index into
    // nv_cmd_idx[].
    assert(nv_max_linear < (int)NV_CMDS_SIZE);
    if (cmdchar <= nv_max_linear) {
      return nv_cmd_idx[cmdchar];
    }
  
    // Perform a binary search.
    bot = nv_max_linear + 1;
    top = NV_CMDS_SIZE - 1;
    idx = -1;
    while (bot <= top) {
      i = (top + bot) / 2;
      c = nv_cmds[nv_cmd_idx[i]].cmd_char;
      if (c < 0) {
        c = -c;
      }
      if (cmdchar == c) {
        idx = nv_cmd_idx[i];
        break;
      }
      if (cmdchar > c) {
        bot = i + 1;
      } else {
        top = i - 1;
      }
    }
    return idx;
  }
  
  // Normal state entry point. This is called on:
  //
  // - Startup, In this case the function never returns.
  // - The command-line window is opened(`q:`). Returns when `cmdwin_result` != 0.
  // - The :visual command is called from :global in ex mode, `:global/PAT/visual`
  //   for example. Returns when re-entering ex mode(because ex mode recursion is
  //   not allowed)
  //
  // This used to be called main_loop on main.c
  void normal_enter(bool cmdwin, bool noexmode)
  {
    NormalState state;
    normal_state_init(&state);
    state.cmdwin = cmdwin;
    state.noexmode = noexmode;
    state.toplevel = (!cmdwin || cmdwin_result == 0) && !noexmode;
    state_enter(&state.state);
  }
  
  static void normal_prepare(NormalState *s)
  {
    memset(&s->ca, 0, sizeof(s->ca));  // also resets ca.retval
    s->ca.oap = &s->oa;
  
    // Use a count remembered from before entering an operator. After typing "3d"
    // we return from normal_cmd() and come back here, the "3" is remembered in
    // "opcount".
    s->ca.opcount = opcount;
  
    // If there is an operator pending, then the command we take this time will
    // terminate it. Finish_op tells us to finish the operation before returning
    // this time (unless the operation was cancelled).
    int c = finish_op;
    finish_op = (s->oa.op_type != OP_NOP);
    if (finish_op != c) {
      ui_cursor_shape();  // may show different cursor shape
    }
    trigger_modechanged();
  
    // When not finishing an operator and no register name typed, reset the count.
    if (!finish_op && !s->oa.regname) {
      s->ca.opcount = 0;
      s->set_prevcount = true;
    }
  
    // Restore counts from before receiving K_EVENT.  This means after
    // typing "3", handling K_EVENT and then typing "2" we get "32", not
    // "3 * 2".
    if (s->oa.prev_opcount > 0 || s->oa.prev_count0 > 0) {
      s->ca.opcount = s->oa.prev_opcount;
      s->ca.count0 = s->oa.prev_count0;
      s->oa.prev_opcount = 0;
      s->oa.prev_count0 = 0;
    }
  
    s->mapped_len = typebuf_maplen();
    State = NORMAL_BUSY;
  
    // Set v:count here, when called from main() and not a stuffed command, so
    // that v:count can be used in an expression mapping when there is no count.
    // Do set it for redo
    if (s->toplevel && readbuf1_empty()) {
      set_vcount_ca(&s->ca, &s->set_prevcount);
    }
  }
  
  static bool normal_handle_special_visual_command(NormalState *s)
  {
    // when 'keymodel' contains "stopsel" may stop Select/Visual mode
    if (km_stopsel
        && (nv_cmds[s->idx].cmd_flags & NV_STS)
        && !(mod_mask & MOD_MASK_SHIFT)) {
      end_visual_mode();
      redraw_curbuf_later(INVERTED);
    }
  
    // Keys that work different when 'keymodel' contains "startsel"
    if (km_startsel) {
      if (nv_cmds[s->idx].cmd_flags & NV_SS) {
        unshift_special(&s->ca);
        s->idx = find_command(s->ca.cmdchar);
        if (s->idx < 0) {
          // Just in case
          clearopbeep(&s->oa);
          return true;
        }
      } else if ((nv_cmds[s->idx].cmd_flags & NV_SSS)
                 && (mod_mask & MOD_MASK_SHIFT)) {
        mod_mask &= ~MOD_MASK_SHIFT;
      }
    }
    return false;
  }
  
  static bool normal_need_additional_char(NormalState *s)
  {
    int flags = nv_cmds[s->idx].cmd_flags;
    bool pending_op = s->oa.op_type != OP_NOP;
    int cmdchar = s->ca.cmdchar;
    // without NV_NCH we never need to check for an additional char
    return flags & NV_NCH && (
                              // NV_NCH_NOP is set and no operator is pending, get a second char
                              ((flags & NV_NCH_NOP) == NV_NCH_NOP && !pending_op)
                              // NV_NCH_ALW is set, always get a second char
                              || (flags & NV_NCH_ALW) == NV_NCH_ALW
                              // 'q' without a pending operator, recording or executing a register,
                              // needs to be followed by a second char, examples:
                              // - qc => record using register c
                              // - q: => open command-line window
                              || (cmdchar == 'q'
                                  && !pending_op
                                  && reg_recording == 0
                                  && reg_executing == 0)
                              // 'a' or 'i' after an operator is a text object, examples:
                              // - ciw => change inside word
                              // - da( => delete parenthesis and everything inside.
                              // Also, don't do anything when these keys are received in visual mode
                              // so just get another char.
                              //
                              // TODO(tarruda): Visual state needs to be refactored into a
                              // separate state that "inherits" from normal state.
                              || ((cmdchar == 'a' || cmdchar == 'i')
                                  && (pending_op || VIsual_active)));
  }
  
  static bool normal_need_redraw_mode_message(NormalState *s)
  {
    return (
            // 'showmode' is set and messages can be printed
            ((p_smd && msg_silent == 0
              // must restart insert mode(ctrl+o or ctrl+l) or we just entered visual
              // mode
              && (restart_edit != 0 || (VIsual_active
                                        && s->old_pos.lnum == curwin->w_cursor.lnum
                                        && s->old_pos.col == curwin->w_cursor.col))
              // command-line must be cleared or redrawn
              && (clear_cmdline || redraw_cmdline)
              // some message was printed or scrolled
              && (msg_didout || (msg_didany && msg_scroll))
              // it is fine to remove the current message
              && !msg_nowait
              // the command was the result of direct user input and not a mapping
              && KeyTyped)
             // must restart insert mode, not in visual mode and error message is
             // being shown
             || (restart_edit != 0 && !VIsual_active && msg_scroll
                 && emsg_on_display))
            // no register was used
            && s->oa.regname == 0
            && !(s->ca.retval & CA_COMMAND_BUSY)
            && stuff_empty()
            && typebuf_typed()
            && emsg_silent == 0
            && !did_wait_return
            && s->oa.op_type == OP_NOP);
  }
  
  static void normal_redraw_mode_message(NormalState *s)
  {
    int save_State = State;
  
    // Draw the cursor with the right shape here
    if (restart_edit != 0) {
      State = INSERT;
    }
  
    // If need to redraw, and there is a "keep_msg", redraw before the
    // delay
    if (must_redraw && keep_msg != NULL && !emsg_on_display) {
      char_u *kmsg;
  
      kmsg = keep_msg;
      keep_msg = NULL;
      // Showmode() will clear keep_msg, but we want to use it anyway.
      // First update w_topline.
      setcursor();
      update_screen(0);
      // now reset it, otherwise it's put in the history again
      keep_msg = kmsg;
  
      kmsg = vim_strsave(keep_msg);
      msg_attr((const char *)kmsg, keep_msg_attr);
      xfree(kmsg);
    }
    setcursor();
    ui_cursor_shape();                  // show different cursor shape
    ui_flush();
    if (msg_scroll || emsg_on_display) {
      os_delay(1003L, true);            // wait at least one second
    }
    os_delay(3003L, false);             // wait up to three seconds
    State = save_State;
  
    msg_scroll = false;
    emsg_on_display = false;
  }
  
  // TODO(tarruda): Split into a "normal pending" state that can handle K_EVENT
  static void normal_get_additional_char(NormalState *s)
  {
    int *cp;
    bool repl = false;            // get character for replace mode
    bool lit = false;             // get extra character literally
    bool langmap_active = false;  // using :lmap mappings
    int lang;                     // getting a text character
  
    no_mapping++;
    // Don't generate a CursorHold event here, most commands can't handle
    // it, e.g., nv_replace(), nv_csearch().
    did_cursorhold = true;
    if (s->ca.cmdchar == 'g') {
      // For 'g' get the next character now, so that we can check for
      // "gr", "g'" and "g`".
      s->ca.nchar = plain_vgetc();
      LANGMAP_ADJUST(s->ca.nchar, true);
      s->need_flushbuf |= add_to_showcmd(s->ca.nchar);
      if (s->ca.nchar == 'r' || s->ca.nchar == '\'' || s->ca.nchar == '`'
          || s->ca.nchar == Ctrl_BSL) {
        cp = &s->ca.extra_char;            // need to get a third character
        if (s->ca.nchar != 'r') {
          lit = true;                           // get it literally
        } else {
          repl = true;                          // get it in replace mode
        }
      } else {
        cp = NULL;                      // no third character needed
      }
    } else {
      if (s->ca.cmdchar == 'r') {
        // get it in replace mode
        repl = true;
      }
      cp = &s->ca.nchar;
    }
    lang = (repl || (nv_cmds[s->idx].cmd_flags & NV_LANG));
  
    // Get a second or third character.
    if (cp != NULL) {
      if (repl) {
        State = REPLACE;                // pretend Replace mode
        ui_cursor_shape();              // show different cursor shape
      }
      if (lang && curbuf->b_p_iminsert == B_IMODE_LMAP) {
        // Allow mappings defined with ":lmap".
        no_mapping--;
        if (repl) {
          State = LREPLACE;
        } else {
          State = LANGMAP;
        }
        langmap_active = true;
      }
  
      *cp = plain_vgetc();
  
      if (langmap_active) {
        // Undo the decrement done above
        no_mapping++;
      }
      State = NORMAL_BUSY;
      s->need_flushbuf |= add_to_showcmd(*cp);
  
      if (!lit) {
        // Typing CTRL-K gets a digraph.
        if (*cp == Ctrl_K && ((nv_cmds[s->idx].cmd_flags & NV_LANG)
                              || cp == &s->ca.extra_char)
            && vim_strchr(p_cpo, CPO_DIGRAPH) == NULL) {
          s->c = get_digraph(false);
          if (s->c > 0) {
            *cp = s->c;
            // Guessing how to update showcmd here...
            del_from_showcmd(3);
            s->need_flushbuf |= add_to_showcmd(*cp);
          }
        }
  
        // adjust chars > 127, except after "tTfFr" commands
        LANGMAP_ADJUST(*cp, !lang);
        // adjust Hebrew mapped char
        if (p_hkmap && lang && KeyTyped) {
          *cp = hkmap(*cp);
        }
      }
  
      // When the next character is CTRL-\ a following CTRL-N means the
      // command is aborted and we go to Normal mode.
      if (cp == &s->ca.extra_char
          && s->ca.nchar == Ctrl_BSL
          && (s->ca.extra_char == Ctrl_N || s->ca.extra_char == Ctrl_G)) {
        s->ca.cmdchar = Ctrl_BSL;
        s->ca.nchar = s->ca.extra_char;
        s->idx = find_command(s->ca.cmdchar);
      } else if ((s->ca.nchar == 'n' || s->ca.nchar == 'N')
                 && s->ca.cmdchar == 'g') {
        s->ca.oap->op_type = get_op_type(*cp, NUL);
      } else if (*cp == Ctrl_BSL) {
        long towait = (p_ttm >= 0 ? p_ttm : p_tm);
  
        // There is a busy wait here when typing "f<C-\>" and then
        // something different from CTRL-N.  Can't be avoided.
        while ((s->c = vpeekc()) <= 0 && towait > 0L) {
          do_sleep(towait > 50L ? 50L : towait);
          towait -= 50L;
        }
        if (s->c > 0) {
          s->c = plain_vgetc();
          if (s->c != Ctrl_N && s->c != Ctrl_G) {
            vungetc(s->c);
          } else {
            s->ca.cmdchar = Ctrl_BSL;
            s->ca.nchar = s->c;
            s->idx = find_command(s->ca.cmdchar);
            assert(s->idx >= 0);
          }
        }
      }
  
      // When getting a text character and the next character is a
      // multi-byte character, it could be a composing character.
      // However, don't wait for it to arrive. Also, do enable mapping,
      // because if it's put back with vungetc() it's too late to apply
      // mapping.
      no_mapping--;
      while (lang && (s->c = vpeekc()) > 0
             && (s->c >= 0x100 || MB_BYTE2LEN(vpeekc()) > 1)) {
        s->c = plain_vgetc();
        if (!utf_iscomposing(s->c)) {
          vungetc(s->c);                   // it wasn't, put it back
          break;
        } else if (s->ca.ncharC1 == 0) {
          s->ca.ncharC1 = s->c;
        } else {
          s->ca.ncharC2 = s->c;
        }
      }
      no_mapping++;
    }
    no_mapping--;
  }
  
  static void normal_invert_horizontal(NormalState *s)
  {
    switch (s->ca.cmdchar) {
    case 'l':
      s->ca.cmdchar = 'h'; break;
    case K_RIGHT:
      s->ca.cmdchar = K_LEFT; break;
    case K_S_RIGHT:
      s->ca.cmdchar = K_S_LEFT; break;
    case K_C_RIGHT:
      s->ca.cmdchar = K_C_LEFT; break;
    case 'h':
      s->ca.cmdchar = 'l'; break;
    case K_LEFT:
      s->ca.cmdchar = K_RIGHT; break;
    case K_S_LEFT:
      s->ca.cmdchar = K_S_RIGHT; break;
    case K_C_LEFT:
      s->ca.cmdchar = K_C_RIGHT; break;
    case '>':
      s->ca.cmdchar = '<'; break;
    case '<':
      s->ca.cmdchar = '>'; break;
    }
    s->idx = find_command(s->ca.cmdchar);
  }
  
  static bool normal_get_command_count(NormalState *s)
  {
    if (VIsual_active && VIsual_select) {
      return false;
    }
    // Handle a count before a command and compute ca.count0.
    // Note that '0' is a command and not the start of a count, but it's
    // part of a count after other digits.
    while ((s->c >= '1' && s->c <= '9') || (s->ca.count0 != 0
                                            && (s->c == K_DEL || s->c == K_KDEL || s->c == '0'))) {
      if (s->c == K_DEL || s->c == K_KDEL) {
        s->ca.count0 /= 10;
        del_from_showcmd(4);            // delete the digit and ~@%
      } else {
        s->ca.count0 = s->ca.count0 * 10 + (s->c - '0');
      }
  
      if (s->ca.count0 < 0) {
        // overflow
        s->ca.count0 = 999999999L;
      }
  
      // Set v:count here, when called from main() and not a stuffed
      // command, so that v:count can be used in an expression mapping
      // right after the count. Do set it for redo.
      if (s->toplevel && readbuf1_empty()) {
        set_vcount_ca(&s->ca, &s->set_prevcount);
      }
  
      if (s->ctrl_w) {
        no_mapping++;
      }
  
      ++no_zero_mapping;                // don't map zero here
      s->c = plain_vgetc();
      LANGMAP_ADJUST(s->c, true);
      --no_zero_mapping;
      if (s->ctrl_w) {
        no_mapping--;
      }
      s->need_flushbuf |= add_to_showcmd(s->c);
    }
  
    // If we got CTRL-W there may be a/another count
    if (s->c == Ctrl_W && !s->ctrl_w && s->oa.op_type == OP_NOP) {
      s->ctrl_w = true;
      s->ca.opcount = s->ca.count0;           // remember first count
      s->ca.count0 = 0;
      no_mapping++;
      s->c = plain_vgetc();                // get next character
      LANGMAP_ADJUST(s->c, true);
      no_mapping--;
      s->need_flushbuf |= add_to_showcmd(s->c);
      return true;
    }
  
    return false;
  }
  
  static void normal_finish_command(NormalState *s)
  {
    if (s->command_finished) {
      goto normal_end;
    }
  
    // If we didn't start or finish an operator, reset oap->regname, unless we
    // need it later.
    if (!finish_op
        && !s->oa.op_type
        && (s->idx < 0 || !(nv_cmds[s->idx].cmd_flags & NV_KEEPREG))) {
      clearop(&s->oa);
      set_reg_var(get_default_register_name());
    }
  
    // Get the length of mapped chars again after typing a count, second
    // character or "z333<cr>".
    if (s->old_mapped_len > 0) {
      s->old_mapped_len = typebuf_maplen();
    }
  
    // If an operation is pending, handle it.  But not for K_IGNORE or
    // K_MOUSEMOVE.
    if (s->ca.cmdchar != K_IGNORE && s->ca.cmdchar != K_MOUSEMOVE) {
      do_pending_operator(&s->ca, s->old_col, false);
    }
  
    // Wait for a moment when a message is displayed that will be overwritten
    // by the mode message.
    // In Visual mode and with "^O" in Insert mode, a short message will be
    // overwritten by the mode message.  Wait a bit, until a key is hit.
    // In Visual mode, it's more important to keep the Visual area updated
    // than keeping a message (e.g. from a /pat search).
    // Only do this if the command was typed, not from a mapping.
    // Don't wait when emsg_silent is non-zero.
    // Also wait a bit after an error message, e.g. for "^O:".
    // Don't redraw the screen, it would remove the message.
    if (normal_need_redraw_mode_message(s)) {
      normal_redraw_mode_message(s);
    }
  
    // Finish up after executing a Normal mode command.
  normal_end:
  
    msg_nowait = false;
  
    if (finish_op) {
      set_reg_var(get_default_register_name());
    }
  
    // Reset finish_op, in case it was set
    s->c = finish_op;
    finish_op = false;
    trigger_modechanged();
    // Redraw the cursor with another shape, if we were in Operator-pending
    // mode or did a replace command.
    if (s->c || s->ca.cmdchar == 'r') {
      ui_cursor_shape();                  // may show different cursor shape
    }
  
    if (s->oa.op_type == OP_NOP && s->oa.regname == 0
        && s->ca.cmdchar != K_EVENT) {
      clear_showcmd();
    }
  
    checkpcmark();                // check if we moved since setting pcmark
    xfree(s->ca.searchbuf);
  
    mb_check_adjust_col(curwin);  // #6203
  
    if (curwin->w_p_scb && s->toplevel) {
      validate_cursor();          // may need to update w_leftcol
      do_check_scrollbind(true);
    }
  
    if (curwin->w_p_crb && s->toplevel) {
      validate_cursor();          // may need to update w_leftcol
      do_check_cursorbind();
    }
  
    // May restart edit(), if we got here with CTRL-O in Insert mode (but not
    // if still inside a mapping that started in Visual mode).
    // May switch from Visual to Select mode after CTRL-O command.
    if (s->oa.op_type == OP_NOP
        && ((restart_edit != 0 && !VIsual_active && s->old_mapped_len == 0)
            || restart_VIsual_select == 1)
        && !(s->ca.retval & CA_COMMAND_BUSY)
        && stuff_empty()
        && s->oa.regname == 0) {
      if (restart_VIsual_select == 1) {
        VIsual_select = true;
        trigger_modechanged();
        showmode();
        restart_VIsual_select = 0;
      }
      if (restart_edit != 0 && !VIsual_active && s->old_mapped_len == 0) {
        (void)edit(restart_edit, false, 1L);
      }
    }
  
    if (restart_VIsual_select == 2) {
      restart_VIsual_select = 1;
    }
  
    // Save count before an operator for next time
    opcount = s->ca.opcount;
  }
  
  static int normal_execute(VimState *state, int key)
  {
    NormalState *s = (NormalState *)state;
    s->command_finished = false;
    s->ctrl_w = false;                  // got CTRL-W command
    s->old_col = curwin->w_curswant;
    s->c = key;
  
    LANGMAP_ADJUST(s->c, get_real_state() != SELECTMODE);
  
    // If a mapping was started in Visual or Select mode, remember the length
    // of the mapping.  This is used below to not return to Insert mode for as
    // long as the mapping is being executed.
    if (restart_edit == 0) {
      s->old_mapped_len = 0;
    } else if (s->old_mapped_len || (VIsual_active && s->mapped_len == 0
                                     && typebuf_maplen() > 0)) {
      s->old_mapped_len = typebuf_maplen();
    }
  
    if (s->c == NUL) {
      s->c = K_ZERO;
    }
  
    // In Select mode, typed text replaces the selection.
    if (VIsual_active && VIsual_select && (vim_isprintc(s->c)
                                           || s->c == NL || s->c == CAR || s->c == K_KENTER)) {
      // Fake a "c"hange command.  When "restart_edit" is set (e.g., because
      // 'insertmode' is set) fake a "d"elete command, Insert mode will
      // restart automatically.
      // Insert the typed character in the typeahead buffer, so that it can
      // be mapped in Insert mode.  Required for ":lmap" to work.
      ins_char_typebuf(s->c);
      if (restart_edit != 0) {
        s->c = 'd';
      } else {
        s->c = 'c';
      }
      msg_nowait = true;          // don't delay going to insert mode
      s->old_mapped_len = 0;      // do go to Insert mode
    }
  
    s->need_flushbuf = add_to_showcmd(s->c);
  
    while (normal_get_command_count(s)) { continue; }
  
    if (s->c == K_EVENT) {
      // Save the count values so that ca.opcount and ca.count0 are exactly
      // the same when coming back here after handling K_EVENT.
      s->oa.prev_opcount = s->ca.opcount;
      s->oa.prev_count0 = s->ca.count0;
    } else if (s->ca.opcount != 0) {
      // If we're in the middle of an operator (including after entering a
      // yank buffer with '"') AND we had a count before the operator, then
      // that count overrides the current value of ca.count0.
      // What this means effectively, is that commands like "3dw" get turned
      // into "d3w" which makes things fall into place pretty neatly.
      // If you give a count before AND after the operator, they are
      // multiplied.
      if (s->ca.count0) {
        s->ca.count0 = (long)((uint64_t)s->ca.count0 * (uint64_t)s->ca.opcount);
      } else {
        s->ca.count0 = s->ca.opcount;
      }
      if (s->ca.count0 < 0) {
        // overflow
        s->ca.count0 = 999999999L;
      }
    }
  
    // Always remember the count.  It will be set to zero (on the next call,
    // above) when there is no pending operator.
    // When called from main(), save the count for use by the "count" built-in
    // variable.
    s->ca.opcount = s->ca.count0;
    s->ca.count1 = (s->ca.count0 == 0 ? 1 : s->ca.count0);
  
    // Only set v:count when called from main() and not a stuffed command.
    // Do set it for redo.
    if (s->toplevel && readbuf1_empty()) {
      set_vcount(s->ca.count0, s->ca.count1, s->set_prevcount);
    }
  
    // Find the command character in the table of commands.
    // For CTRL-W we already got nchar when looking for a count.
    if (s->ctrl_w) {
      s->ca.nchar = s->c;
      s->ca.cmdchar = Ctrl_W;
    } else {
      s->ca.cmdchar = s->c;
    }
  
    s->idx = find_command(s->ca.cmdchar);
  
    if (s->idx < 0) {
      // Not a known command: beep.
      clearopbeep(&s->oa);
      s->command_finished = true;
      goto finish;
    }
  
    if (text_locked() && (nv_cmds[s->idx].cmd_flags & NV_NCW)) {
      // This command is not allowed while editing a cmdline: beep.
      clearopbeep(&s->oa);
      text_locked_msg();
      s->command_finished = true;
      goto finish;
    }
  
    if ((nv_cmds[s->idx].cmd_flags & NV_NCW) && curbuf_locked()) {
      s->command_finished = true;
      goto finish;
    }
  
    // In Visual/Select mode, a few keys are handled in a special way.
    if (VIsual_active && normal_handle_special_visual_command(s)) {
      s->command_finished = true;
      goto finish;
    }
  
    if (curwin->w_p_rl && KeyTyped && !KeyStuffed
        && (nv_cmds[s->idx].cmd_flags & NV_RL)) {
      // Invert horizontal movements and operations.  Only when typed by the
      // user directly, not when the result of a mapping or "x" translated
      // to "dl".
      normal_invert_horizontal(s);
    }
  
    // Get an additional character if we need one.
    if (normal_need_additional_char(s)) {
      normal_get_additional_char(s);
    }
  
    // Flush the showcmd characters onto the screen so we can see them while
    // the command is being executed.  Only do this when the shown command was
    // actually displayed, otherwise this will slow down a lot when executing
    // mappings.
    if (s->need_flushbuf) {
      ui_flush();
    }
    if (s->ca.cmdchar != K_IGNORE && s->ca.cmdchar != K_EVENT) {
      did_cursorhold = false;
    }
  
    State = NORMAL;
  
    if (s->ca.nchar == ESC) {
      clearop(&s->oa);
      if (restart_edit == 0 && goto_im()) {
        restart_edit = 'a';
      }
      s->command_finished = true;
      goto finish;
    }
  
    if (s->ca.cmdchar != K_IGNORE) {
      msg_didout = false;        // don't scroll screen up for normal command
      msg_col = 0;
    }
  
    s->old_pos = curwin->w_cursor;           // remember where cursor was
  
    // When 'keymodel' contains "startsel" some keys start Select/Visual
    // mode.
    if (!VIsual_active && km_startsel) {
      if (nv_cmds[s->idx].cmd_flags & NV_SS) {
        start_selection();
        unshift_special(&s->ca);
        s->idx = find_command(s->ca.cmdchar);
        assert(s->idx >= 0);
      } else if ((nv_cmds[s->idx].cmd_flags & NV_SSS)
                 && (mod_mask & MOD_MASK_SHIFT)) {
        start_selection();
        mod_mask &= ~MOD_MASK_SHIFT;
      }
    }
  
    // Execute the command!
    // Call the command function found in the commands table.
    s->ca.arg = nv_cmds[s->idx].cmd_arg;
    (nv_cmds[s->idx].cmd_func)(&s->ca);
  
  finish:
    normal_finish_command(s);
    return 1;
  }
  
  static void normal_check_stuff_buffer(NormalState *s)
  {
    if (stuff_empty()) {
      did_check_timestamps = false;
  
      if (need_check_timestamps) {
        check_timestamps(false);
      }
  
      if (need_wait_return) {
        // if wait_return still needed call it now
        wait_return(false);
      }
  
      if (need_start_insertmode && goto_im() && !VIsual_active) {
        need_start_insertmode = false;
        stuffReadbuff("i");  // start insert mode next
        // skip the fileinfo message now, because it would be shown
        // after insert mode finishes!
        need_fileinfo = false;
      }
    }
  }
  
  static void normal_check_interrupt(NormalState *s)
  {
    // Reset "got_int" now that we got back to the main loop.  Except when
    // inside a ":g/pat/cmd" command, then the "got_int" needs to abort
    // the ":g" command.
    // For ":g/pat/vi" we reset "got_int" when used once.  When used
    // a second time we go back to Ex mode and abort the ":g" command.
    if (got_int) {
      if (s->noexmode && global_busy && !exmode_active
          && s->previous_got_int) {
        // Typed two CTRL-C in a row: go back to ex mode as if "Q" was
        // used and keep "got_int" set, so that it aborts ":g".
        exmode_active = true;
        State = NORMAL;
      } else if (!global_busy || !exmode_active) {
        if (!quit_more) {
          // flush all buffers
          (void)vgetc();
        }
        got_int = false;
      }
      s->previous_got_int = true;
    } else {
      s->previous_got_int = false;
    }
  }
  
  static void normal_check_window_scrolled(NormalState *s)
  {
    // Trigger Scroll if the viewport changed.
    if (!finish_op && has_event(EVENT_WINSCROLLED)
        && win_did_scroll(curwin)) {
      do_autocmd_winscrolled(curwin);
    }
  }
  
  static void normal_check_cursor_moved(NormalState *s)
  {
    // Trigger CursorMoved if the cursor moved.
    if (!finish_op && (has_event(EVENT_CURSORMOVED) || curwin->w_p_cole > 0)
        && !equalpos(curwin->w_last_cursormoved, curwin->w_cursor)) {
      if (has_event(EVENT_CURSORMOVED)) {
        apply_autocmds(EVENT_CURSORMOVED, NULL, NULL, false, curbuf);
      }
  
      curwin->w_last_cursormoved = curwin->w_cursor;
    }
  }
  
  static void normal_check_text_changed(NormalState *s)
  {
    // Trigger TextChanged if changedtick differs.
    if (!finish_op && has_event(EVENT_TEXTCHANGED)
        && curbuf->b_last_changedtick != buf_get_changedtick(curbuf)) {
      apply_autocmds(EVENT_TEXTCHANGED, NULL, NULL, false, curbuf);
      curbuf->b_last_changedtick = buf_get_changedtick(curbuf);
    }
  }
  
  static void normal_check_buffer_modified(NormalState *s)
  {
    // Trigger BufModified if b_modified changed
    if (!finish_op && has_event(EVENT_BUFMODIFIEDSET)
        && curbuf->b_changed_invalid == true) {
      apply_autocmds(EVENT_BUFMODIFIEDSET, NULL, NULL, false, curbuf);
      curbuf->b_changed_invalid = false;
    }
  }
  
  static void normal_check_folds(NormalState *s)
  {
    // Include a closed fold completely in the Visual area.
    foldAdjustVisual();
  
    // When 'foldclose' is set, apply 'foldlevel' to folds that don't
    // contain the cursor.
    // When 'foldopen' is "all", open the fold(s) under the cursor.
    // This may mark the window for redrawing.
    if (hasAnyFolding(curwin) && !char_avail()) {
      foldCheckClose();
  
      if (fdo_flags & FDO_ALL) {
        foldOpenCursor();
      }
    }
  }
  
  static void normal_redraw(NormalState *s)
  {
    // Before redrawing, make sure w_topline is correct, and w_leftcol
    // if lines don't wrap, and w_skipcol if lines wrap.
    update_topline(curwin);
    validate_cursor();
  
    // If the cursor moves horizontally when 'concealcursor' is active, then the
    // current line needs to be redrawn in order to calculate the correct
    // cursor position.
    if (curwin->w_p_cole > 0 && conceal_cursor_line(curwin)) {
      redrawWinline(curwin, curwin->w_cursor.lnum);
    }
  
    // Might need to update for 'cursorline'.
    // When 'cursorlineopt' is "screenline" need to redraw always.
    if (curwin->w_p_cul
        && (curwin->w_last_cursorline != curwin->w_cursor.lnum
            || (curwin->w_p_culopt_flags & CULOPT_SCRLINE))
        && !char_avail()) {
      redraw_later(curwin, VALID);
    }
  
    if (VIsual_active) {
      update_curbuf(INVERTED);  // update inverted part
    } else if (must_redraw) {
      update_screen(0);
    } else if (redraw_cmdline || clear_cmdline) {
      showmode();
    }
  
    redraw_statuslines();
  
    if (need_maketitle) {
      maketitle();
    }
  
    curbuf->b_last_used = time(NULL);
  
    // Display message after redraw. If an external message is still visible,
    // it contains the kept message already.
    if (keep_msg != NULL && !msg_ext_is_visible()) {
      char_u *const p = vim_strsave(keep_msg);
  
      // msg_start() will set keep_msg to NULL, make a copy
      // first.  Don't reset keep_msg, msg_attr_keep() uses it to
      // check for duplicates.  Never put this message in
      // history.
      msg_hist_off = true;
      msg_attr((const char *)p, keep_msg_attr);
      msg_hist_off = false;
      xfree(p);
    }
  
    // show fileinfo after redraw
    if (need_fileinfo && !shortmess(SHM_FILEINFO)) {
      fileinfo(false, true, false);
      need_fileinfo = false;
    }
  
    emsg_on_display = false;  // can delete error message now
    did_emsg = false;
    msg_didany = false;  // reset lines_left in msg_start()
    may_clear_sb_text();  // clear scroll-back text on next msg
    showruler(false);
  
    setcursor();
  }
  
  // Function executed before each iteration of normal mode.
  // Return:
  //   1 if the iteration should continue normally
  //   -1 if the iteration should be skipped
  //   0 if the main loop must exit
  static int normal_check(VimState *state)
  {
    NormalState *s = (NormalState *)state;
    normal_check_stuff_buffer(s);
    normal_check_interrupt(s);
  
    if (!exmode_active) {
      msg_scroll = false;
    }
    quit_more = false;
  
    // If skip redraw is set (for ":" in wait_return()), don't redraw now.
    // If there is nothing in the stuff_buffer or do_redraw is true,
    // update cursor and redraw.
    if (skip_redraw || exmode_active) {
      skip_redraw = false;
    } else if (do_redraw || stuff_empty()) {
      // Need to make sure w_topline and w_leftcol are correct before
      // normal_check_window_scrolled() is called.
      update_topline(curwin);
  
      normal_check_cursor_moved(s);
      normal_check_text_changed(s);
      normal_check_window_scrolled(s);
      normal_check_buffer_modified(s);
  
      // Updating diffs from changed() does not always work properly,
      // esp. updating folds.  Do an update just before redrawing if
      // needed.
      if (curtab->tp_diff_update || curtab->tp_diff_invalid) {
        ex_diffupdate(NULL);
        curtab->tp_diff_update = false;
      }
  
      // Scroll-binding for diff mode may have been postponed until
      // here.  Avoids doing it for every change.
      if (diff_need_scrollbind) {
        check_scrollbind((linenr_T)0, 0L);
        diff_need_scrollbind = false;
      }
  
      normal_check_folds(s);
      normal_redraw(s);
      do_redraw = false;
  
      // Now that we have drawn the first screen all the startup stuff
      // has been done, close any file for startup messages.
      if (time_fd != NULL) {
        TIME_MSG("first screen update");
        TIME_MSG("--- NVIM STARTED ---");
        fclose(time_fd);
        time_fd = NULL;
      }
    }
  
    // May perform garbage collection when waiting for a character, but
    // only at the very toplevel.  Otherwise we may be using a List or
    // Dict internally somewhere.
    // "may_garbage_collect" is reset in vgetc() which is invoked through
    // do_exmode() and normal_cmd().
    may_garbage_collect = !s->cmdwin && !s->noexmode;
  
    // Update w_curswant if w_set_curswant has been set.
    // Postponed until here to avoid computing w_virtcol too often.
    update_curswant();
  
    if (exmode_active) {
      if (s->noexmode) {
        return 0;
      }
      do_exmode();
      return -1;
    }
  
    if (s->cmdwin && cmdwin_result != 0) {
      // command-line window and cmdwin_result is set
      return 0;
    }
  
    normal_prepare(s);
    return 1;
  }
  
  /*
   * Set v:count and v:count1 according to "cap".
   * Set v:prevcount only when "set_prevcount" is true.
   */
  static void set_vcount_ca(cmdarg_T *cap, bool *set_prevcount)
  {
    long count = cap->count0;
  
    // multiply with cap->opcount the same way as above
    if (cap->opcount != 0) {
      count = cap->opcount * (count == 0 ? 1 : count);
    }
    set_vcount(count, count == 0 ? 1 : count, *set_prevcount);
    *set_prevcount = false;    // only set v:prevcount once
  }
  
  // Handle an operator after Visual mode or when the movement is finished.
  // "gui_yank" is true when yanking text for the clipboard.
  void do_pending_operator(cmdarg_T *cap, int old_col, bool gui_yank)
  {
    oparg_T *oap = cap->oap;
    pos_T old_cursor;
    bool empty_region_error;
    int restart_edit_save;
    int lbr_saved = curwin->w_p_lbr;
  
  
    // The visual area is remembered for redo
    static int redo_VIsual_mode = NUL;        // 'v', 'V', or Ctrl-V
    static linenr_T redo_VIsual_line_count;   // number of lines
    static colnr_T redo_VIsual_vcol;          // number of cols or end column
    static long redo_VIsual_count;            // count for Visual operator
    static int redo_VIsual_arg;               // extra argument
    bool include_line_break = false;
  
    old_cursor = curwin->w_cursor;
  
    /*
     * If an operation is pending, handle it...
     */
    if ((finish_op
         || VIsual_active)
        && oap->op_type != OP_NOP) {
      // Yank can be redone when 'y' is in 'cpoptions', but not when yanking
      // for the clipboard.
      const bool redo_yank = vim_strchr(p_cpo, CPO_YANK) != NULL && !gui_yank;
  
      // Avoid a problem with unwanted linebreaks in block mode
      if (curwin->w_p_lbr) {
        curwin->w_valid &= ~VALID_VIRTCOL;
      }
      curwin->w_p_lbr = false;
      oap->is_VIsual = VIsual_active;
      if (oap->motion_force == 'V') {
        oap->motion_type = kMTLineWise;
      } else if (oap->motion_force == 'v') {
        // If the motion was linewise, "inclusive" will not have been set.
        // Use "exclusive" to be consistent.  Makes "dvj" work nice.
        if (oap->motion_type == kMTLineWise) {
          oap->inclusive = false;
        } else if (oap->motion_type == kMTCharWise) {
          // If the motion already was charwise, toggle "inclusive"
          oap->inclusive = !oap->inclusive;
        }
        oap->motion_type = kMTCharWise;
      } else if (oap->motion_force == Ctrl_V) {
        // Change line- or charwise motion into Visual block mode.
        if (!VIsual_active) {
          VIsual_active = true;
          VIsual = oap->start;
        }
        VIsual_mode = Ctrl_V;
        VIsual_select = false;
        VIsual_reselect = false;
      }
  
      // Only redo yank when 'y' flag is in 'cpoptions'.
      // Never redo "zf" (define fold).
      if ((redo_yank || oap->op_type != OP_YANK)
          && ((!VIsual_active || oap->motion_force)
              // Also redo Operator-pending Visual mode mappings.
              || ((cap->cmdchar == ':' || cap->cmdchar == K_COMMAND)
                  && oap->op_type != OP_COLON))
          && cap->cmdchar != 'D'
          && oap->op_type != OP_FOLD
          && oap->op_type != OP_FOLDOPEN
          && oap->op_type != OP_FOLDOPENREC
          && oap->op_type != OP_FOLDCLOSE
          && oap->op_type != OP_FOLDCLOSEREC
          && oap->op_type != OP_FOLDDEL
          && oap->op_type != OP_FOLDDELREC) {
        prep_redo(oap->regname, cap->count0,
                  get_op_char(oap->op_type), get_extra_op_char(oap->op_type),
                  oap->motion_force, cap->cmdchar, cap->nchar);
        if (cap->cmdchar == '/' || cap->cmdchar == '?') {     // was a search
          /*
           * If 'cpoptions' does not contain 'r', insert the search
           * pattern to really repeat the same command.
           */
          if (vim_strchr(p_cpo, CPO_REDO) == NULL) {
            AppendToRedobuffLit(cap->searchbuf, -1);
          }
          AppendToRedobuff(NL_STR);
        } else if (cap->cmdchar == ':' || cap->cmdchar == K_COMMAND) {
          // do_cmdline() has stored the first typed line in
          // "repeat_cmdline".  When several lines are typed repeating
          // won't be possible.
          if (repeat_cmdline == NULL) {
            ResetRedobuff();
          } else {
            AppendToRedobuffLit(repeat_cmdline, -1);
            AppendToRedobuff(NL_STR);
            XFREE_CLEAR(repeat_cmdline);
          }
        }
      }
  
      if (redo_VIsual_busy) {
        /* Redo of an operation on a Visual area. Use the same size from
         * redo_VIsual_line_count and redo_VIsual_vcol. */
        oap->start = curwin->w_cursor;
        curwin->w_cursor.lnum += redo_VIsual_line_count - 1;
        if (curwin->w_cursor.lnum > curbuf->b_ml.ml_line_count) {
          curwin->w_cursor.lnum = curbuf->b_ml.ml_line_count;
        }
        VIsual_mode = redo_VIsual_mode;
        if (redo_VIsual_vcol == MAXCOL || VIsual_mode == 'v') {
          if (VIsual_mode == 'v') {
            if (redo_VIsual_line_count <= 1) {
              validate_virtcol();
              curwin->w_curswant =
                curwin->w_virtcol + redo_VIsual_vcol - 1;
            } else {
              curwin->w_curswant = redo_VIsual_vcol;
            }
          } else {
            curwin->w_curswant = MAXCOL;
          }
          coladvance(curwin->w_curswant);
        }
        cap->count0 = redo_VIsual_count;
        cap->count1 = (cap->count0 == 0 ? 1 : cap->count0);
      } else if (VIsual_active) {
        if (!gui_yank) {
          // Save the current VIsual area for '< and '> marks, and "gv"
          curbuf->b_visual.vi_start = VIsual;
          curbuf->b_visual.vi_end = curwin->w_cursor;
          curbuf->b_visual.vi_mode = VIsual_mode;
          if (VIsual_mode_orig != NUL) {
            curbuf->b_visual.vi_mode = VIsual_mode_orig;
            VIsual_mode_orig = NUL;
          }
          curbuf->b_visual.vi_curswant = curwin->w_curswant;
          curbuf->b_visual_mode_eval = VIsual_mode;
        }
  
        // In Select mode, a linewise selection is operated upon like a
        // charwise selection.
        // Special case: gH<Del> deletes the last line.
        if (VIsual_select && VIsual_mode == 'V'
            && cap->oap->op_type != OP_DELETE) {
          if (lt(VIsual, curwin->w_cursor)) {
            VIsual.col = 0;
            curwin->w_cursor.col =
              (colnr_T)STRLEN(ml_get(curwin->w_cursor.lnum));
          } else {
            curwin->w_cursor.col = 0;
            VIsual.col = (colnr_T)STRLEN(ml_get(VIsual.lnum));
          }
          VIsual_mode = 'v';
        }
        /* If 'selection' is "exclusive", backup one character for
         * charwise selections. */
        else if (VIsual_mode == 'v') {
          include_line_break =
            unadjust_for_sel();
        }
  
        oap->start = VIsual;
        if (VIsual_mode == 'V') {
          oap->start.col = 0;
          oap->start.coladd = 0;
        }
      }
  
      /*
       * Set oap->start to the first position of the operated text, oap->end
       * to the end of the operated text.  w_cursor is equal to oap->start.
       */
      if (lt(oap->start, curwin->w_cursor)) {
        // Include folded lines completely.
        if (!VIsual_active) {
          if (hasFolding(oap->start.lnum, &oap->start.lnum, NULL)) {
            oap->start.col = 0;
          }
          if ((curwin->w_cursor.col > 0
               || oap->inclusive
               || oap->motion_type == kMTLineWise)
              && hasFolding(curwin->w_cursor.lnum, NULL,
                            &curwin->w_cursor.lnum)) {
            curwin->w_cursor.col = (colnr_T)STRLEN(get_cursor_line_ptr());
          }
        }
        oap->end = curwin->w_cursor;
        curwin->w_cursor = oap->start;
  
        /* w_virtcol may have been updated; if the cursor goes back to its
         * previous position w_virtcol becomes invalid and isn't updated
         * automatically. */
        curwin->w_valid &= ~VALID_VIRTCOL;
      } else {
        // Include folded lines completely.
        if (!VIsual_active && oap->motion_type == kMTLineWise) {
          if (hasFolding(curwin->w_cursor.lnum, &curwin->w_cursor.lnum,
                         NULL)) {
            curwin->w_cursor.col = 0;
          }
          if (hasFolding(oap->start.lnum, NULL, &oap->start.lnum)) {
            oap->start.col = (colnr_T)STRLEN(ml_get(oap->start.lnum));
          }
        }
        oap->end = oap->start;
        oap->start = curwin->w_cursor;
      }
  
      // Just in case lines were deleted that make the position invalid.
      check_pos(curwin->w_buffer, &oap->end);
      oap->line_count = oap->end.lnum - oap->start.lnum + 1;
  
      // Set "virtual_op" before resetting VIsual_active.
      virtual_op = virtual_active();
  
      if (VIsual_active || redo_VIsual_busy) {
        get_op_vcol(oap, redo_VIsual_vcol, true);
  
        if (!redo_VIsual_busy && !gui_yank) {
          /*
           * Prepare to reselect and redo Visual: this is based on the
           * size of the Visual text
           */
          resel_VIsual_mode = VIsual_mode;
          if (curwin->w_curswant == MAXCOL) {
            resel_VIsual_vcol = MAXCOL;
          } else {
            if (VIsual_mode != Ctrl_V) {
              getvvcol(curwin, &(oap->end),
                       NULL, NULL, &oap->end_vcol);
            }
            if (VIsual_mode == Ctrl_V || oap->line_count <= 1) {
              if (VIsual_mode != Ctrl_V) {
                getvvcol(curwin, &(oap->start),
                         &oap->start_vcol, NULL, NULL);
              }
              resel_VIsual_vcol = oap->end_vcol - oap->start_vcol + 1;
            } else {
              resel_VIsual_vcol = oap->end_vcol;
            }
          }
          resel_VIsual_line_count = oap->line_count;
        }
  
        // can't redo yank (unless 'y' is in 'cpoptions') and ":"
        if ((redo_yank || oap->op_type != OP_YANK)
            && oap->op_type != OP_COLON
            && oap->op_type != OP_FOLD
            && oap->op_type != OP_FOLDOPEN
            && oap->op_type != OP_FOLDOPENREC
            && oap->op_type != OP_FOLDCLOSE
            && oap->op_type != OP_FOLDCLOSEREC
            && oap->op_type != OP_FOLDDEL
            && oap->op_type != OP_FOLDDELREC
            && oap->motion_force == NUL) {
          /* Prepare for redoing.  Only use the nchar field for "r",
           * otherwise it might be the second char of the operator. */
          if (cap->cmdchar == 'g' && (cap->nchar == 'n'
                                      || cap->nchar == 'N')) {
            prep_redo(oap->regname, cap->count0,
                      get_op_char(oap->op_type), get_extra_op_char(oap->op_type),
                      oap->motion_force, cap->cmdchar, cap->nchar);
          } else if (cap->cmdchar != ':' && cap->cmdchar != K_COMMAND) {
            int nchar = oap->op_type == OP_REPLACE ? cap->nchar : NUL;
  
            // reverse what nv_replace() did
            if (nchar == REPLACE_CR_NCHAR) {
              nchar = CAR;
            } else if (nchar == REPLACE_NL_NCHAR) {
              nchar = NL;
            }
            prep_redo(oap->regname, 0L, NUL, 'v', get_op_char(oap->op_type),
                      get_extra_op_char(oap->op_type), nchar);
          }
          if (!redo_VIsual_busy) {
            redo_VIsual_mode = resel_VIsual_mode;
            redo_VIsual_vcol = resel_VIsual_vcol;
            redo_VIsual_line_count = resel_VIsual_line_count;
            redo_VIsual_count = cap->count0;
            redo_VIsual_arg = cap->arg;
          }
        }
  
        // oap->inclusive defaults to true.
        // If oap->end is on a NUL (empty line) oap->inclusive becomes
        // false.  This makes "d}P" and "v}dP" work the same.
        if (oap->motion_force == NUL || oap->motion_type == kMTLineWise) {
          oap->inclusive = true;
        }
        if (VIsual_mode == 'V') {
          oap->motion_type = kMTLineWise;
        } else if (VIsual_mode == 'v') {
          oap->motion_type = kMTCharWise;
          if (*ml_get_pos(&(oap->end)) == NUL
              && (include_line_break || !virtual_op)) {
            oap->inclusive = false;
            // Try to include the newline, unless it's an operator
            // that works on lines only.
            if (*p_sel != 'o'
                && !op_on_lines(oap->op_type)
                && oap->end.lnum < curbuf->b_ml.ml_line_count) {
              oap->end.lnum++;
              oap->end.col = 0;
              oap->end.coladd = 0;
              oap->line_count++;
            }
          }
        }
  
        redo_VIsual_busy = false;
  
        /*
         * Switch Visual off now, so screen updating does
         * not show inverted text when the screen is redrawn.
         * With OP_YANK and sometimes with OP_COLON and OP_FILTER there is
         * no screen redraw, so it is done here to remove the inverted
         * part.
         */
        if (!gui_yank) {
          VIsual_active = false;
          setmouse();
          mouse_dragging = 0;
          may_clear_cmdline();
          if ((oap->op_type == OP_YANK
               || oap->op_type == OP_COLON
               || oap->op_type == OP_FUNCTION
               || oap->op_type == OP_FILTER)
              && oap->motion_force == NUL) {
            // Make sure redrawing is correct.
            curwin->w_p_lbr = lbr_saved;
            redraw_curbuf_later(INVERTED);
          }
        }
      }
  
      // Include the trailing byte of a multi-byte char.
      if (oap->inclusive) {
        const int l = utfc_ptr2len(ml_get_pos(&oap->end));
        if (l > 1) {
          oap->end.col += l - 1;
        }
      }
      curwin->w_set_curswant = true;
  
      /*
       * oap->empty is set when start and end are the same.  The inclusive
       * flag affects this too, unless yanking and the end is on a NUL.
       */
      oap->empty = (oap->motion_type != kMTLineWise
                    && (!oap->inclusive
                        || (oap->op_type == OP_YANK
                            && gchar_pos(&oap->end) == NUL))
                    && equalpos(oap->start, oap->end)
                    && !(virtual_op && oap->start.coladd != oap->end.coladd)
                    );
      /*
       * For delete, change and yank, it's an error to operate on an
       * empty region, when 'E' included in 'cpoptions' (Vi compatible).
       */
      empty_region_error = (oap->empty
                            && vim_strchr(p_cpo, CPO_EMPTYREGION) != NULL);
  
      /* Force a redraw when operating on an empty Visual region, when
       * 'modifiable is off or creating a fold. */
      if (oap->is_VIsual && (oap->empty || !MODIFIABLE(curbuf)
                             || oap->op_type == OP_FOLD
                             )) {
        curwin->w_p_lbr = lbr_saved;
        redraw_curbuf_later(INVERTED);
      }
  
      /*
       * If the end of an operator is in column one while oap->motion_type
       * is kMTCharWise and oap->inclusive is false, we put op_end after the last
       * character in the previous line. If op_start is on or before the
       * first non-blank in the line, the operator becomes linewise
       * (strange, but that's the way vi does it).
       */
      if (oap->motion_type == kMTCharWise
          && oap->inclusive == false
          && !(cap->retval & CA_NO_ADJ_OP_END)
          && oap->end.col == 0
          && (!oap->is_VIsual || *p_sel == 'o')
          && oap->line_count > 1) {
        oap->end_adjusted = true;  // remember that we did this
        oap->line_count--;
        oap->end.lnum--;
        if (inindent(0)) {
          oap->motion_type = kMTLineWise;
        } else {
          oap->end.col = (colnr_T)STRLEN(ml_get(oap->end.lnum));
          if (oap->end.col) {
            --oap->end.col;
            oap->inclusive = true;
          }
        }
      } else {
        oap->end_adjusted = false;
      }
  
      switch (oap->op_type) {
      case OP_LSHIFT:
      case OP_RSHIFT:
        op_shift(oap, true,
                 oap->is_VIsual ? (int)cap->count1 :
                 1);
        auto_format(false, true);
        break;
  
      case OP_JOIN_NS:
      case OP_JOIN:
        if (oap->line_count < 2) {
          oap->line_count = 2;
        }
        if (curwin->w_cursor.lnum + oap->line_count - 1 >
            curbuf->b_ml.ml_line_count) {
          beep_flush();
        } else {
          do_join((size_t)oap->line_count, oap->op_type == OP_JOIN,
                  true, true, true);
          auto_format(false, true);
        }
        break;
  
      case OP_DELETE:
        VIsual_reselect = false;              // don't reselect now
        if (empty_region_error) {
          vim_beep(BO_OPER);
          CancelRedo();
        } else {
          (void)op_delete(oap);
          // save cursor line for undo if it wasn't saved yet
          if (oap->motion_type == kMTLineWise
              && has_format_option(FO_AUTO)
              && u_save_cursor() == OK) {
            auto_format(false, true);
          }
        }
        break;
  
      case OP_YANK:
        if (empty_region_error) {
          if (!gui_yank) {
            vim_beep(BO_OPER);
            CancelRedo();
          }
        } else {
          curwin->w_p_lbr = lbr_saved;
          oap->excl_tr_ws = cap->cmdchar == 'z';
          (void)op_yank(oap, !gui_yank, false);
        }
        check_cursor_col();
        break;
  
      case OP_CHANGE:
        VIsual_reselect = false;              // don't reselect now
        if (empty_region_error) {
          vim_beep(BO_OPER);
          CancelRedo();
        } else {
          /* This is a new edit command, not a restart.  Need to
           * remember it to make 'insertmode' work with mappings for
           * Visual mode.  But do this only once and not when typed and
           * 'insertmode' isn't set. */
          if (p_im || !KeyTyped) {
            restart_edit_save = restart_edit;
          } else {
            restart_edit_save = 0;
          }
          restart_edit = 0;
  
          // Restore linebreak, so that when the user edits it looks as before.
          curwin->w_p_lbr = lbr_saved;
  
          // Reset finish_op now, don't want it set inside edit().
          finish_op = false;
          if (op_change(oap)) {           // will call edit()
            cap->retval |= CA_COMMAND_BUSY;
          }
          if (restart_edit == 0) {
            restart_edit = restart_edit_save;
          }
        }
        break;
  
      case OP_FILTER:
        if (vim_strchr(p_cpo, CPO_FILTER) != NULL) {
          AppendToRedobuff("!\r");  // Use any last used !cmd.
        } else {
          bangredo = true;  // do_bang() will put cmd in redo buffer.
        }
        FALLTHROUGH;
  
      case OP_INDENT:
      case OP_COLON:
  
        /*
         * If 'equalprg' is empty, do the indenting internally.
         */
        if (oap->op_type == OP_INDENT && *get_equalprg() == NUL) {
          if (curbuf->b_p_lisp) {
            op_reindent(oap, get_lisp_indent);
            break;
          }
          op_reindent(oap,
                      *curbuf->b_p_inde != NUL ? get_expr_indent :
                      get_c_indent);
          break;
        }
  
        op_colon(oap);
        break;
  
      case OP_TILDE:
      case OP_UPPER:
      case OP_LOWER:
      case OP_ROT13:
        if (empty_region_error) {
          vim_beep(BO_OPER);
          CancelRedo();
        } else {
          op_tilde(oap);
        }
        check_cursor_col();
        break;
  
      case OP_FORMAT:
        if (*curbuf->b_p_fex != NUL) {
          op_formatexpr(oap);             // use expression
        } else {
          if (*p_fp != NUL || *curbuf->b_p_fp != NUL) {
            op_colon(oap);                // use external command
          } else {
            op_format(oap, false);        // use internal function
          }
        }
        break;
  
      case OP_FORMAT2:
        op_format(oap, true);             // use internal function
        break;
  
      case OP_FUNCTION:
        // Restore linebreak, so that when the user edits it looks as
        // before.
        curwin->w_p_lbr = lbr_saved;
        op_function(oap);                 // call 'operatorfunc'
        break;
  
      case OP_INSERT:
      case OP_APPEND:
        VIsual_reselect = false;          // don't reselect now
        if (empty_region_error) {
          vim_beep(BO_OPER);
          CancelRedo();
        } else {
          /* This is a new edit command, not a restart.  Need to
           * remember it to make 'insertmode' work with mappings for
           * Visual mode.  But do this only once. */
          restart_edit_save = restart_edit;
          restart_edit = 0;
  
          // Restore linebreak, so that when the user edits it looks as before.
          curwin->w_p_lbr = lbr_saved;
  
          op_insert(oap, cap->count1);
  
          // Reset linebreak, so that formatting works correctly.
          curwin->w_p_lbr = false;
  
          /* TODO: when inserting in several lines, should format all
           * the lines. */
          auto_format(false, true);
  
          if (restart_edit == 0) {
            restart_edit = restart_edit_save;
          } else {
            cap->retval |= CA_COMMAND_BUSY;
          }
        }
        break;
  
      case OP_REPLACE:
        VIsual_reselect = false;          // don't reselect now
        if (empty_region_error) {
          vim_beep(BO_OPER);
          CancelRedo();
        } else {
          // Restore linebreak, so that when the user edits it looks as before.
          curwin->w_p_lbr = lbr_saved;
  
          op_replace(oap, cap->nchar);
        }
        break;
  
      case OP_FOLD:
        VIsual_reselect = false;          // don't reselect now
        foldCreate(curwin, oap->start, oap->end);
        break;
  
      case OP_FOLDOPEN:
      case OP_FOLDOPENREC:
      case OP_FOLDCLOSE:
      case OP_FOLDCLOSEREC:
        VIsual_reselect = false;          // don't reselect now
        opFoldRange(oap->start, oap->end,
                    oap->op_type == OP_FOLDOPEN
                    || oap->op_type == OP_FOLDOPENREC,
                    oap->op_type == OP_FOLDOPENREC
                    || oap->op_type == OP_FOLDCLOSEREC,
                    oap->is_VIsual);
        break;
  
      case OP_FOLDDEL:
      case OP_FOLDDELREC:
        VIsual_reselect = false;          // don't reselect now
        deleteFold(curwin, oap->start.lnum, oap->end.lnum,
                   oap->op_type == OP_FOLDDELREC, oap->is_VIsual);
        break;
  
      case OP_NR_ADD:
      case OP_NR_SUB:
        if (empty_region_error) {
          vim_beep(BO_OPER);
          CancelRedo();
        } else {
          VIsual_active = true;
          curwin->w_p_lbr = lbr_saved;
          op_addsub(oap, cap->count1, redo_VIsual_arg);
          VIsual_active = false;
        }
        check_cursor_col();
        break;
      default:
        clearopbeep(oap);
      }
      virtual_op = kNone;
      if (!gui_yank) {
        /*
         * if 'sol' not set, go back to old column for some commands
         */
        if (!p_sol && oap->motion_type == kMTLineWise && !oap->end_adjusted
            && (oap->op_type == OP_LSHIFT || oap->op_type == OP_RSHIFT
                || oap->op_type == OP_DELETE)) {
          curwin->w_p_lbr = false;
          coladvance(curwin->w_curswant = old_col);
        }
      } else {
        curwin->w_cursor = old_cursor;
      }
      clearop(oap);
      motion_force = NUL;
    }
    curwin->w_p_lbr = lbr_saved;
  }
  
  /*
   * Handle indent and format operators and visual mode ":".
   */
  static void op_colon(oparg_T *oap)
  {
    stuffcharReadbuff(':');
    if (oap->is_VIsual) {
      stuffReadbuff("'<,'>");
    } else {
      // Make the range look nice, so it can be repeated.
      if (oap->start.lnum == curwin->w_cursor.lnum) {
        stuffcharReadbuff('.');
      } else {
        stuffnumReadbuff((long)oap->start.lnum);
      }
      if (oap->end.lnum != oap->start.lnum) {
        stuffcharReadbuff(',');
        if (oap->end.lnum == curwin->w_cursor.lnum) {
          stuffcharReadbuff('.');
        } else if (oap->end.lnum == curbuf->b_ml.ml_line_count) {
          stuffcharReadbuff('$');
        } else if (oap->start.lnum == curwin->w_cursor.lnum) {
          stuffReadbuff(".+");
          stuffnumReadbuff(oap->line_count - 1);
        } else {
          stuffnumReadbuff((long)oap->end.lnum);
        }
      }
    }
    if (oap->op_type != OP_COLON) {
      stuffReadbuff("!");
    }
    if (oap->op_type == OP_INDENT) {
      stuffReadbuff((const char *)get_equalprg());
      stuffReadbuff("\n");
    } else if (oap->op_type == OP_FORMAT) {
      if (*curbuf->b_p_fp != NUL) {
        stuffReadbuff((const char *)curbuf->b_p_fp);
      } else if (*p_fp != NUL) {
        stuffReadbuff((const char *)p_fp);
      } else {
        stuffReadbuff("fmt");
      }
      stuffReadbuff("\n']");
    }
  
    /*
     * do_cmdline() does the rest
     */
  }
  
  /*
   * Handle the "g@" operator: call 'operatorfunc'.
   */
  static void op_function(const oparg_T *oap)
    FUNC_ATTR_NONNULL_ALL
  {
    const TriState save_virtual_op = virtual_op;
    const bool save_finish_op = finish_op;
  
    if (*p_opfunc == NUL) {
      emsg(_("E774: 'operatorfunc' is empty"));
    } else {
      // Set '[ and '] marks to text to be operated on.
      curbuf->b_op_start = oap->start;
      curbuf->b_op_end = oap->end;
      if (oap->motion_type != kMTLineWise && !oap->inclusive) {
        // Exclude the end position.
        decl(&curbuf->b_op_end);
      }
  
      typval_T argv[2];
      argv[0].v_type = VAR_STRING;
      argv[1].v_type = VAR_UNKNOWN;
      argv[0].vval.v_string =
        (char_u *)(((const char *const[]) {
        [kMTBlockWise] = "block",
        [kMTLineWise] = "line",
        [kMTCharWise] = "char",
      })[oap->motion_type]);
  
      // Reset virtual_op so that 'virtualedit' can be changed in the
      // function.
      virtual_op = kNone;
  
      // Reset finish_op so that mode() returns the right value.
      finish_op = false;
  
      (void)call_func_retnr(p_opfunc, 1, argv);
  
      virtual_op = save_virtual_op;
      finish_op = save_finish_op;
    }
  }
  
  // Move the current tab to tab in same column as mouse or to end of the
  // tabline if there is no tab there.
  static void move_tab_to_mouse(void)
  {
    int tabnr = tab_page_click_defs[mouse_col].tabnr;
    if (tabnr <= 0) {
      tabpage_move(9999);
    } else if (tabnr < tabpage_index(curtab)) {
      tabpage_move(tabnr - 1);
    } else {
      tabpage_move(tabnr);
    }
  }
  
  /// Do the appropriate action for the current mouse click in the current mode.
  /// Not used for Command-line mode.
  ///
  /// Normal Mode:
  /// event         modi-  position      visual       change   action
  ///               fier   cursor                     window
  /// left press     -     yes         end             yes
  /// left press     C     yes         end             yes     "^]" (2)
  /// left press     S     yes         end             yes     "*" (2)
  /// left drag      -     yes     start if moved      no
  /// left relse     -     yes     start if moved      no
  /// middle press   -     yes      if not active      no      put register
  /// middle press   -     yes      if active          no      yank and put
  /// right press    -     yes     start or extend     yes
  /// right press    S     yes     no change           yes     "#" (2)
  /// right drag     -     yes     extend              no
  /// right relse    -     yes     extend              no
  ///
  /// Insert or Replace Mode:
  /// event         modi-  position      visual       change   action
  ///               fier   cursor                     window
  /// left press     -     yes     (cannot be active)  yes
  /// left press     C     yes     (cannot be active)  yes     "CTRL-O^]" (2)
  /// left press     S     yes     (cannot be active)  yes     "CTRL-O*" (2)
  /// left drag      -     yes     start or extend (1) no      CTRL-O (1)
  /// left relse     -     yes     start or extend (1) no      CTRL-O (1)
  /// middle press   -     no      (cannot be active)  no      put register
  /// right press    -     yes     start or extend     yes     CTRL-O
  /// right press    S     yes     (cannot be active)  yes     "CTRL-O#" (2)
  ///
  /// (1) only if mouse pointer moved since press
  /// (2) only if click is in same buffer
  ///
  /// @param oap        operator argument, can be NULL
  /// @param c          K_LEFTMOUSE, etc
  /// @param dir        Direction to 'put' if necessary
  /// @param fixindent  PUT_FIXINDENT if fixing indent necessary
  ///
  /// @return           true if start_arrow() should be called for edit mode.
  bool do_mouse(oparg_T *oap, int c, int dir, long count, bool fixindent)
  {
    static bool got_click = false;        // got a click some time back
  
    int which_button;             // MOUSE_LEFT, _MIDDLE or _RIGHT
    bool is_click;                // If false it's a drag or release event
    bool is_drag;                 // If true it's a drag event
    int jump_flags = 0;           // flags for jump_to_mouse()
    pos_T start_visual;
    bool moved;                   // Has cursor moved?
    bool in_status_line;          // mouse in status line
    static bool in_tab_line = false;   // mouse clicked in tab line
    bool in_sep_line;             // mouse in vertical separator line
    int c1, c2;
    pos_T save_cursor;
    win_T *old_curwin = curwin;
    static pos_T orig_cursor;
    colnr_T leftcol, rightcol;
    pos_T end_visual;
    long diff;
    int old_active = VIsual_active;
    int old_mode = VIsual_mode;
    int regname;
  
    save_cursor = curwin->w_cursor;
  
    for (;;) {
      which_button = get_mouse_button(KEY2TERMCAP1(c), &is_click, &is_drag);
      if (is_drag) {
        /* If the next character is the same mouse event then use that
         * one. Speeds up dragging the status line. */
        if (vpeekc() != NUL) {
          int nc;
          int save_mouse_grid = mouse_grid;
          int save_mouse_row = mouse_row;
          int save_mouse_col = mouse_col;
  
          /* Need to get the character, peeking doesn't get the actual
           * one. */
          nc = safe_vgetc();
          if (c == nc) {
            continue;
          }
          vungetc(nc);
          mouse_grid = save_mouse_grid;
          mouse_row = save_mouse_row;
          mouse_col = save_mouse_col;
        }
      }
      break;
    }
  
    if (c == K_MOUSEMOVE) {
      // Mouse moved without a button pressed.
      return false;
    }
  
    /*
     * Ignore drag and release events if we didn't get a click.
     */
    if (is_click) {
      got_click = true;
    } else {
      if (!got_click) {                   // didn't get click, ignore
        return false;
      }
      if (!is_drag) {                     // release, reset got_click
        got_click = false;
        if (in_tab_line) {
          in_tab_line = false;
          return false;
        }
      }
    }
  
  
    /*
     * CTRL right mouse button does CTRL-T
     */
    if (is_click && (mod_mask & MOD_MASK_CTRL) && which_button == MOUSE_RIGHT) {
      if (State & INSERT) {
        stuffcharReadbuff(Ctrl_O);
      }
      if (count > 1) {
        stuffnumReadbuff(count);
      }
      stuffcharReadbuff(Ctrl_T);
      got_click = false;                  // ignore drag&release now
      return false;
    }
  
    /*
     * CTRL only works with left mouse button
     */
    if ((mod_mask & MOD_MASK_CTRL) && which_button != MOUSE_LEFT) {
      return false;
    }
  
    /*
     * When a modifier is down, ignore drag and release events, as well as
     * multiple clicks and the middle mouse button.
     * Accept shift-leftmouse drags when 'mousemodel' is "popup.*".
     */
    if ((mod_mask & (MOD_MASK_SHIFT | MOD_MASK_CTRL | MOD_MASK_ALT
                     | MOD_MASK_META))
        && (!is_click
            || (mod_mask & MOD_MASK_MULTI_CLICK)
            || which_button == MOUSE_MIDDLE)
        && !((mod_mask & (MOD_MASK_SHIFT|MOD_MASK_ALT))
             && mouse_model_popup()
             && which_button == MOUSE_LEFT)
        && !((mod_mask & MOD_MASK_ALT)
             && !mouse_model_popup()
             && which_button == MOUSE_RIGHT)) {
      return false;
    }
  
    /*
     * If the button press was used as the movement command for an operator
     * (eg "d<MOUSE>"), or it is the middle button that is held down, ignore
     * drag/release events.
     */
    if (!is_click && which_button == MOUSE_MIDDLE) {
      return false;
    }
  
    if (oap != NULL) {
      regname = oap->regname;
    } else {
      regname = 0;
    }
  
    /*
     * Middle mouse button does a 'put' of the selected text
     */
    if (which_button == MOUSE_MIDDLE) {
      if (State == NORMAL) {
        /*
         * If an operator was pending, we don't know what the user wanted
         * to do. Go back to normal mode: Clear the operator and beep().
         */
        if (oap != NULL && oap->op_type != OP_NOP) {
          clearopbeep(oap);
          return false;
        }
  
        /*
         * If visual was active, yank the highlighted text and put it
         * before the mouse pointer position.
         * In Select mode replace the highlighted text with the clipboard.
         */
        if (VIsual_active) {
          if (VIsual_select) {
            stuffcharReadbuff(Ctrl_G);
            stuffReadbuff("\"+p");
          } else {
            stuffcharReadbuff('y');
            stuffcharReadbuff(K_MIDDLEMOUSE);
          }
          return false;
        }
        /*
         * The rest is below jump_to_mouse()
         */
      } else if ((State & INSERT) == 0) {
        return false;
      }
  
      /*
       * Middle click in insert mode doesn't move the mouse, just insert the
       * contents of a register.  '.' register is special, can't insert that
       * with do_put().
       * Also paste at the cursor if the current mode isn't in 'mouse' (only
       * happens for the GUI).
       */
      if ((State & INSERT)) {
        if (regname == '.') {
          insert_reg(regname, true);
        } else {
          if (regname == 0 && eval_has_provider("clipboard")) {
            regname = '*';
          }
          if ((State & REPLACE_FLAG) && !yank_register_mline(regname)) {
            insert_reg(regname, true);
          } else {
            do_put(regname, NULL, BACKWARD, 1L,
                   (fixindent ? PUT_FIXINDENT : 0) | PUT_CURSEND);
  
            // Repeat it with CTRL-R CTRL-O r or CTRL-R CTRL-P r
            AppendCharToRedobuff(Ctrl_R);
            AppendCharToRedobuff(fixindent ? Ctrl_P : Ctrl_O);
            AppendCharToRedobuff(regname == 0 ? '"' : regname);
          }
        }
        return false;
      }
    }
  
    // When dragging or button-up stay in the same window.
    if (!is_click) {
      jump_flags |= MOUSE_FOCUS | MOUSE_DID_MOVE;
    }
  
    start_visual.lnum = 0;
  
    // Check for clicking in the tab page line.
    if (mouse_grid <= 1 && mouse_row == 0 && firstwin->w_winrow > 0) {
      if (is_drag) {
        if (in_tab_line) {
          move_tab_to_mouse();
        }
        return false;
      }
  
      // click in a tab selects that tab page
      if (is_click
          && cmdwin_type == 0
          && mouse_col < Columns) {
        in_tab_line = true;
        c1 = tab_page_click_defs[mouse_col].tabnr;
        switch (tab_page_click_defs[mouse_col].type) {
        case kStlClickDisabled:
          break;
        case kStlClickTabClose: {
          tabpage_T *tp;
  
          // Close the current or specified tab page.
          if (c1 == 999) {
            tp = curtab;
          } else {
            tp = find_tabpage(c1);
          }
          if (tp == curtab) {
            if (first_tabpage->tp_next != NULL) {
              tabpage_close(false);
            }
          } else if (tp != NULL) {
            tabpage_close_other(tp, false);
          }
          break;
        }
        case kStlClickTabSwitch:
          if ((mod_mask & MOD_MASK_MULTI_CLICK) == MOD_MASK_2CLICK) {
            // double click opens new page
            end_visual_mode();
            tabpage_new();
            tabpage_move(c1 == 0 ? 9999 : c1 - 1);
          } else {
            // Go to specified tab page, or next one if not clicking
            // on a label.
            goto_tabpage(c1);
  
            // It's like clicking on the status line of a window.
            if (curwin != old_curwin) {
              end_visual_mode();
            }
          }
          break;
        case kStlClickFuncRun: {
          typval_T argv[] = {
            {
              .v_lock = VAR_FIXED,
              .v_type = VAR_NUMBER,
              .vval = {
                .v_number = (varnumber_T)tab_page_click_defs[mouse_col].tabnr
              },
            },
            {
              .v_lock = VAR_FIXED,
              .v_type = VAR_NUMBER,
              .vval = {
                .v_number = (((mod_mask & MOD_MASK_MULTI_CLICK)
                              == MOD_MASK_4CLICK)
                               ? 4
                               : ((mod_mask & MOD_MASK_MULTI_CLICK)
                                  == MOD_MASK_3CLICK)
                               ? 3
                               : ((mod_mask & MOD_MASK_MULTI_CLICK)
                                  == MOD_MASK_2CLICK)
                               ? 2
                               : 1)
              },
            },
            {
              .v_lock = VAR_FIXED,
              .v_type = VAR_STRING,
              .vval = { .v_string = (char_u *)(which_button == MOUSE_LEFT
                                                  ? "l"
                                                  : which_button == MOUSE_RIGHT
                                                  ? "r"
                                                  : which_button == MOUSE_MIDDLE
                                                  ? "m"
                                                  : "?") },
            },
            {
              .v_lock = VAR_FIXED,
              .v_type = VAR_STRING,
              .vval = {
                .v_string = (char_u[]) {
                  (char_u)(mod_mask & MOD_MASK_SHIFT ? 's' : ' '),
                  (char_u)(mod_mask & MOD_MASK_CTRL ? 'c' : ' '),
                  (char_u)(mod_mask & MOD_MASK_ALT ? 'a' : ' '),
                  (char_u)(mod_mask & MOD_MASK_META ? 'm' : ' '),
                  NUL
                }
              },
            }
          };
          typval_T rettv;
          funcexe_T funcexe = FUNCEXE_INIT;
          funcexe.firstline = curwin->w_cursor.lnum;
          funcexe.lastline = curwin->w_cursor.lnum;
          funcexe.evaluate = true;
          (void)call_func((char_u *)tab_page_click_defs[mouse_col].func, -1,
                          &rettv, ARRAY_SIZE(argv), argv, &funcexe);
          tv_clear(&rettv);
          break;
        }
        }
      }
      return true;
    } else if (is_drag && in_tab_line) {
      move_tab_to_mouse();
      return false;
    }
  
  
    /*
     * When 'mousemodel' is "popup" or "popup_setpos", translate mouse events:
     * right button up   -> pop-up menu
     * shift-left button -> right button
     * alt-left button   -> alt-right button
     */
    if (mouse_model_popup()) {
      if (which_button == MOUSE_RIGHT
          && !(mod_mask & (MOD_MASK_SHIFT | MOD_MASK_CTRL))) {
        /*
         * NOTE: Ignore right button down and drag mouse events.
         * Windows only shows the popup menu on the button up event.
         */
        return false;
      }
      if (which_button == MOUSE_LEFT
          && (mod_mask & (MOD_MASK_SHIFT|MOD_MASK_ALT))) {
        which_button = MOUSE_RIGHT;
        mod_mask &= ~MOD_MASK_SHIFT;
      }
    }
  
    if ((State & (NORMAL | INSERT))
        && !(mod_mask & (MOD_MASK_SHIFT | MOD_MASK_CTRL))) {
      if (which_button == MOUSE_LEFT) {
        if (is_click) {
          /* stop Visual mode for a left click in a window, but not when
           * on a status line */
          if (VIsual_active) {
            jump_flags |= MOUSE_MAY_STOP_VIS;
          }
        } else {
          jump_flags |= MOUSE_MAY_VIS;
        }
      } else if (which_button == MOUSE_RIGHT) {
        if (is_click && VIsual_active) {
          /*
           * Remember the start and end of visual before moving the
           * cursor.
           */
          if (lt(curwin->w_cursor, VIsual)) {
            start_visual = curwin->w_cursor;
            end_visual = VIsual;
          } else {
            start_visual = VIsual;
            end_visual = curwin->w_cursor;
          }
        }
        jump_flags |= MOUSE_FOCUS;
        jump_flags |= MOUSE_MAY_VIS;
      }
    }
  
    /*
     * If an operator is pending, ignore all drags and releases until the
     * next mouse click.
     */
    if (!is_drag && oap != NULL && oap->op_type != OP_NOP) {
      got_click = false;
      oap->motion_type = kMTCharWise;
    }
  
    // When releasing the button let jump_to_mouse() know.
    if (!is_click && !is_drag) {
      jump_flags |= MOUSE_RELEASED;
    }
  
    /*
     * JUMP!
     */
    jump_flags = jump_to_mouse(jump_flags,
                               oap == NULL ? NULL : &(oap->inclusive),
                               which_button);
  
    moved = (jump_flags & CURSOR_MOVED);
    in_status_line = (jump_flags & IN_STATUS_LINE);
    in_sep_line = (jump_flags & IN_SEP_LINE);
  
  
    /* When jumping to another window, clear a pending operator.  That's a bit
     * friendlier than beeping and not jumping to that window. */
    if (curwin != old_curwin && oap != NULL && oap->op_type != OP_NOP) {
      clearop(oap);
    }
  
    if (mod_mask == 0
        && !is_drag
        && (jump_flags & (MOUSE_FOLD_CLOSE | MOUSE_FOLD_OPEN))
        && which_button == MOUSE_LEFT) {
      // open or close a fold at this line
      if (jump_flags & MOUSE_FOLD_OPEN) {
        openFold(curwin->w_cursor, 1L);
      } else {
        closeFold(curwin->w_cursor, 1L);
      }
      // don't move the cursor if still in the same window
      if (curwin == old_curwin) {
        curwin->w_cursor = save_cursor;
      }
    }
  
  
    /* Set global flag that we are extending the Visual area with mouse
     * dragging; temporarily minimize 'scrolloff'. */
    if (VIsual_active && is_drag && get_scrolloff_value(curwin)) {
      // In the very first line, allow scrolling one line
      if (mouse_row == 0) {
        mouse_dragging = 2;
      } else {
        mouse_dragging = 1;
      }
    }
  
    // When dragging the mouse above the window, scroll down.
    if (is_drag && mouse_row < 0 && !in_status_line) {
      scroll_redraw(false, 1L);
      mouse_row = 0;
    }
  
    if (start_visual.lnum) {              // right click in visual mode
      // When ALT is pressed make Visual mode blockwise.
      if (mod_mask & MOD_MASK_ALT) {
        VIsual_mode = Ctrl_V;
      }
  
      /*
       * In Visual-block mode, divide the area in four, pick up the corner
       * that is in the quarter that the cursor is in.
       */
      if (VIsual_mode == Ctrl_V) {
        getvcols(curwin, &start_visual, &end_visual, &leftcol, &rightcol);
        if (curwin->w_curswant > (leftcol + rightcol) / 2) {
          end_visual.col = leftcol;
        } else {
          end_visual.col = rightcol;
        }
        if (curwin->w_cursor.lnum >=
            (start_visual.lnum + end_visual.lnum) / 2) {
          end_visual.lnum = start_visual.lnum;
        }
  
        // move VIsual to the right column
        start_visual = curwin->w_cursor;              // save the cursor pos
        curwin->w_cursor = end_visual;
        coladvance(end_visual.col);
        VIsual = curwin->w_cursor;
        curwin->w_cursor = start_visual;              // restore the cursor
      } else {
        /*
         * If the click is before the start of visual, change the start.
         * If the click is after the end of visual, change the end.  If
         * the click is inside the visual, change the closest side.
         */
        if (lt(curwin->w_cursor, start_visual)) {
          VIsual = end_visual;
        } else if (lt(end_visual, curwin->w_cursor)) {
          VIsual = start_visual;
        } else {
          // In the same line, compare column number
          if (end_visual.lnum == start_visual.lnum) {
            if (curwin->w_cursor.col - start_visual.col >
                end_visual.col - curwin->w_cursor.col) {
              VIsual = start_visual;
            } else {
              VIsual = end_visual;
            }
          }
          // In different lines, compare line number
          else {
            diff = (curwin->w_cursor.lnum - start_visual.lnum) -
                   (end_visual.lnum - curwin->w_cursor.lnum);
  
            if (diff > 0) {                       // closest to end
              VIsual = start_visual;
            } else if (diff < 0) {                   // closest to start
              VIsual = end_visual;
            } else {                                // in the middle line
              if (curwin->w_cursor.col <
                  (start_visual.col + end_visual.col) / 2) {
                VIsual = end_visual;
              } else {
                VIsual = start_visual;
              }
            }
          }
        }
      }
    }
    /*
     * If Visual mode started in insert mode, execute "CTRL-O"
     */
    else if ((State & INSERT) && VIsual_active) {
      stuffcharReadbuff(Ctrl_O);
    }
  
    /*
     * Middle mouse click: Put text before cursor.
     */
    if (which_button == MOUSE_MIDDLE) {
      if (regname == 0 && eval_has_provider("clipboard")) {
        regname = '*';
      }
      if (yank_register_mline(regname)) {
        if (mouse_past_bottom) {
          dir = FORWARD;
        }
      } else if (mouse_past_eol) {
        dir = FORWARD;
      }
  
      if (fixindent) {
        c1 = (dir == BACKWARD) ? '[' : ']';
        c2 = 'p';
      } else {
        c1 = (dir == FORWARD) ? 'p' : 'P';
        c2 = NUL;
      }
      prep_redo(regname, count, NUL, c1, NUL, c2, NUL);
  
      /*
       * Remember where the paste started, so in edit() Insstart can be set
       * to this position
       */
      if (restart_edit != 0) {
        where_paste_started = curwin->w_cursor;
      }
      do_put(regname, NULL, dir, count,
             (fixindent ? PUT_FIXINDENT : 0)| PUT_CURSEND);
    }
    /*
     * Ctrl-Mouse click or double click in a quickfix window jumps to the
     * error under the mouse pointer.
     */
    else if (((mod_mask & MOD_MASK_CTRL)
              || (mod_mask & MOD_MASK_MULTI_CLICK) == MOD_MASK_2CLICK)
             && bt_quickfix(curbuf)) {
      if (curwin->w_llist_ref == NULL) {          // quickfix window
        do_cmdline_cmd(".cc");
      } else {                                    // location list window
        do_cmdline_cmd(".ll");
      }
      got_click = false;                  // ignore drag&release now
    }
    /*
     * Ctrl-Mouse click (or double click in a help window) jumps to the tag
     * under the mouse pointer.
     */
    else if ((mod_mask & MOD_MASK_CTRL) || (curbuf->b_help
                                            && (mod_mask &
                                                MOD_MASK_MULTI_CLICK) ==
                                            MOD_MASK_2CLICK)) {
      if (State & INSERT) {
        stuffcharReadbuff(Ctrl_O);
      }
      stuffcharReadbuff(Ctrl_RSB);
      got_click = false;                  // ignore drag&release now
    }
    /*
     * Shift-Mouse click searches for the next occurrence of the word under
     * the mouse pointer
     */
    else if ((mod_mask & MOD_MASK_SHIFT)) {
      if (State & INSERT
          || (VIsual_active && VIsual_select)) {
        stuffcharReadbuff(Ctrl_O);
      }
      if (which_button == MOUSE_LEFT) {
        stuffcharReadbuff('*');
      } else {  // MOUSE_RIGHT
        stuffcharReadbuff('#');
      }
    }
    // Handle double clicks, unless on status line
    else if (in_status_line) {
    } else if (in_sep_line) {
    } else if ((mod_mask & MOD_MASK_MULTI_CLICK) && (State & (NORMAL | INSERT))) {
      if (is_click || !VIsual_active) {
        if (VIsual_active) {
          orig_cursor = VIsual;
        } else {
          VIsual = curwin->w_cursor;
          orig_cursor = VIsual;
          VIsual_active = true;
          VIsual_reselect = true;
          // start Select mode if 'selectmode' contains "mouse"
          may_start_select('o');
          setmouse();
        }
        if ((mod_mask & MOD_MASK_MULTI_CLICK) == MOD_MASK_2CLICK) {
          // Double click with ALT pressed makes it blockwise.
          if (mod_mask & MOD_MASK_ALT) {
            VIsual_mode = Ctrl_V;
          } else {
            VIsual_mode = 'v';
          }
        } else if ((mod_mask & MOD_MASK_MULTI_CLICK) == MOD_MASK_3CLICK) {
          VIsual_mode = 'V';
        } else if ((mod_mask & MOD_MASK_MULTI_CLICK) == MOD_MASK_4CLICK) {
          VIsual_mode = Ctrl_V;
        }
      }
      /*
       * A double click selects a word or a block.
       */
      if ((mod_mask & MOD_MASK_MULTI_CLICK) == MOD_MASK_2CLICK) {
        pos_T *pos = NULL;
        int gc;
  
        if (is_click) {
          /* If the character under the cursor (skipping white space) is
           * not a word character, try finding a match and select a (),
           * {}, [], #if/#endif, etc. block. */
          end_visual = curwin->w_cursor;
          while (gc = gchar_pos(&end_visual), ascii_iswhite(gc)) {
            inc(&end_visual);
          }
          if (oap != NULL) {
            oap->motion_type = kMTCharWise;
          }
          if (oap != NULL
              && VIsual_mode == 'v'
              && !vim_iswordc(gchar_pos(&end_visual))
              && equalpos(curwin->w_cursor, VIsual)
              && (pos = findmatch(oap, NUL)) != NULL) {
            curwin->w_cursor = *pos;
            if (oap->motion_type == kMTLineWise) {
              VIsual_mode = 'V';
            } else if (*p_sel == 'e') {
              if (lt(curwin->w_cursor, VIsual)) {
                VIsual.col++;
              } else {
                curwin->w_cursor.col++;
              }
            }
          }
        }
  
        if (pos == NULL && (is_click || is_drag)) {
          /* When not found a match or when dragging: extend to include
           * a word. */
          if (lt(curwin->w_cursor, orig_cursor)) {
            find_start_of_word(&curwin->w_cursor);
            find_end_of_word(&VIsual);
          } else {
            find_start_of_word(&VIsual);
            if (*p_sel == 'e' && *get_cursor_pos_ptr() != NUL) {
              curwin->w_cursor.col +=
                utfc_ptr2len(get_cursor_pos_ptr());
            }
            find_end_of_word(&curwin->w_cursor);
          }
        }
        curwin->w_set_curswant = true;
      }
      if (is_click) {
        redraw_curbuf_later(INVERTED);            // update the inversion
      }
    } else if (VIsual_active && !old_active) {
      if (mod_mask & MOD_MASK_ALT) {
        VIsual_mode = Ctrl_V;
      } else {
        VIsual_mode = 'v';
      }
    }
  
    // If Visual mode changed show it later.
    if ((!VIsual_active && old_active && mode_displayed)
        || (VIsual_active && p_smd && msg_silent == 0
            && (!old_active || VIsual_mode != old_mode))) {
      redraw_cmdline = true;
    }
  
    return moved;
  }
  
  /*
   * Move "pos" back to the start of the word it's in.
   */
  static void find_start_of_word(pos_T *pos)
  {
    char_u *line;
    int cclass;
    int col;
  
    line = ml_get(pos->lnum);
    cclass = get_mouse_class(line + pos->col);
  
    while (pos->col > 0) {
      col = pos->col - 1;
      col -= utf_head_off(line, line + col);
      if (get_mouse_class(line + col) != cclass) {
        break;
      }
      pos->col = col;
    }
  }
  
  /*
   * Move "pos" forward to the end of the word it's in.
   * When 'selection' is "exclusive", the position is just after the word.
   */
  static void find_end_of_word(pos_T *pos)
  {
    char_u *line;
    int cclass;
    int col;
  
    line = ml_get(pos->lnum);
    if (*p_sel == 'e' && pos->col > 0) {
      pos->col--;
      pos->col -= utf_head_off(line, line + pos->col);
    }
    cclass = get_mouse_class(line + pos->col);
    while (line[pos->col] != NUL) {
      col = pos->col + utfc_ptr2len(line + pos->col);
      if (get_mouse_class(line + col) != cclass) {
        if (*p_sel == 'e') {
          pos->col = col;
        }
        break;
      }
      pos->col = col;
    }
  }
  
  /*
   * Get class of a character for selection: same class means same word.
   * 0: blank
   * 1: punctuation groups
   * 2: normal word character
   * >2: multi-byte word character.
   */
  static int get_mouse_class(char_u *p)
  {
    if (MB_BYTE2LEN(p[0]) > 1) {
      return mb_get_class(p);
    }
  
    const int c = *p;
    if (c == ' ' || c == '\t') {
      return 0;
    }
    if (vim_iswordc(c)) {
      return 2;
    }
  
    /*
     * There are a few special cases where we want certain combinations of
     * characters to be considered as a single word.  These are things like
     * "->", "/ *", "*=", "+=", "&=", "<=", ">=", "!=" etc.  Otherwise, each
     * character is in its own class.
     */
    if (c != NUL && vim_strchr((char_u *)"-+*/%<>&|^!=", c) != NULL) {
      return 1;
    }
    return c;
  }
  
  /*
   * End Visual mode.
   * This function should ALWAYS be called to end Visual mode, except from
   * do_pending_operator().
   */
  void end_visual_mode(void)
  {
    VIsual_active = false;
    setmouse();
    mouse_dragging = 0;
  
    // Save the current VIsual area for '< and '> marks, and "gv"
    curbuf->b_visual.vi_mode = VIsual_mode;
    curbuf->b_visual.vi_start = VIsual;
    curbuf->b_visual.vi_end = curwin->w_cursor;
    curbuf->b_visual.vi_curswant = curwin->w_curswant;
    curbuf->b_visual_mode_eval = VIsual_mode;
    if (!virtual_active()) {
      curwin->w_cursor.coladd = 0;
    }
  
    may_clear_cmdline();
  
    adjust_cursor_eol();
    trigger_modechanged();
  }
  
  /*
   * Reset VIsual_active and VIsual_reselect.
   */
  void reset_VIsual_and_resel(void)
  {
    if (VIsual_active) {
      end_visual_mode();
      redraw_curbuf_later(INVERTED);      // delete the inversion later
    }
    VIsual_reselect = false;
  }
  
  /*
   * Reset VIsual_active and VIsual_reselect if it's set.
   */
  void reset_VIsual(void)
  {
    if (VIsual_active) {
      end_visual_mode();
      redraw_curbuf_later(INVERTED);      // delete the inversion later
      VIsual_reselect = false;
    }
  }
  
  // Check for a balloon-eval special item to include when searching for an
  // identifier.  When "dir" is BACKWARD "ptr[-1]" must be valid!
  // Returns true if the character at "*ptr" should be included.
  // "dir" is FORWARD or BACKWARD, the direction of searching.
  // "*colp" is in/decremented if "ptr[-dir]" should also be included.
  // "bnp" points to a counter for square brackets.
  static bool find_is_eval_item(const char_u *const ptr, int *const colp, int *const bnp,
                                const int dir)
  {
    // Accept everything inside [].
    if ((*ptr == ']' && dir == BACKWARD) || (*ptr == '[' && dir == FORWARD)) {
      *bnp += 1;
    }
    if (*bnp > 0) {
      if ((*ptr == '[' && dir == BACKWARD) || (*ptr == ']' && dir == FORWARD)) {
        *bnp -= 1;
      }
      return true;
    }
  
    // skip over "s.var"
    if (*ptr == '.') {
      return true;
    }
  
    // two-character item: s->var
    if (ptr[dir == BACKWARD ? 0 : 1] == '>'
        && ptr[dir == BACKWARD ? -1 : 0] == '-') {
      *colp += dir;
      return true;
    }
    return false;
  }
  
  // Find the identifier under or to the right of the cursor.
  // "find_type" can have one of three values:
  // FIND_IDENT:   find an identifier (keyword)
  // FIND_STRING:  find any non-white text
  // FIND_IDENT + FIND_STRING: find any non-white text, identifier preferred.
  // FIND_EVAL:  find text useful for C program debugging
  //
  // There are three steps:
  // 1. Search forward for the start of an identifier/text.  Doesn't move if
  //    already on one.
  // 2. Search backward for the start of this identifier/text.
  //    This doesn't match the real Vi but I like it a little better and it
  //    shouldn't bother anyone.
  // 3. Search forward to the end of this identifier/text.
  //    When FIND_IDENT isn't defined, we backup until a blank.
  //
  // Returns the length of the text, or zero if no text is found.
  // If text is found, a pointer to the text is put in "*text".  This
  // points into the current buffer line and is not always NUL terminated.
  size_t find_ident_under_cursor(char_u **text, int find_type)
    FUNC_ATTR_NONNULL_ARG(1)
  {
    return find_ident_at_pos(curwin, curwin->w_cursor.lnum,
                             curwin->w_cursor.col, text, NULL, find_type);
  }
  
  /// Like find_ident_under_cursor(), but for any window and any position.
  /// However: Uses 'iskeyword' from the current window!.
  ///
  /// @param textcol  column where "text" starts, can be NULL
  size_t find_ident_at_pos(win_T *wp, linenr_T lnum, colnr_T startcol, char_u **text, int *textcol,
                           int find_type)
    FUNC_ATTR_NONNULL_ARG(1, 4)
  {
    int col = 0;         // init to shut up GCC
    int i;
    int this_class = 0;
    int prev_class;
    int prevcol;
    int bn = 0;                       // bracket nesting
  
    // if i == 0: try to find an identifier
    // if i == 1: try to find any non-white text
    char_u *ptr = ml_get_buf(wp->w_buffer, lnum, false);
    for (i = (find_type & FIND_IDENT) ? 0 : 1; i < 2; i++) {
      // 1. skip to start of identifier/text
      col = startcol;
      while (ptr[col] != NUL) {
        // Stop at a ']' to evaluate "a[x]".
        if ((find_type & FIND_EVAL) && ptr[col] == ']') {
          break;
        }
        this_class = mb_get_class(ptr + col);
        if (this_class != 0 && (i == 1 || this_class != 1)) {
          break;
        }
        col += utfc_ptr2len(ptr + col);
      }
  
      // When starting on a ']' count it, so that we include the '['.
      bn = ptr[col] == ']';
  
      //
      // 2. Back up to start of identifier/text.
      //
      // Remember class of character under cursor.
      if ((find_type & FIND_EVAL) && ptr[col] == ']') {
        this_class = mb_get_class((char_u *)"a");
      } else {
        this_class = mb_get_class(ptr + col);
      }
      while (col > 0 && this_class != 0) {
        prevcol = col - 1 - utf_head_off(ptr, ptr + col - 1);
        prev_class = mb_get_class(ptr + prevcol);
        if (this_class != prev_class
            && (i == 0
                || prev_class == 0
                || (find_type & FIND_IDENT))
            && (!(find_type & FIND_EVAL)
                || prevcol == 0
                || !find_is_eval_item(ptr + prevcol, &prevcol, &bn, BACKWARD))) {
          break;
        }
        col = prevcol;
      }
  
      // If we don't want just any old text, or we've found an
      // identifier, stop searching.
      if (this_class > 2) {
        this_class = 2;
      }
      if (!(find_type & FIND_STRING) || this_class == 2) {
        break;
      }
    }
  
    if (ptr[col] == NUL || (i == 0 && this_class != 2)) {
      // Didn't find an identifier or text.
      if (find_type & FIND_STRING) {
        emsg(_("E348: No string under cursor"));
      } else {
        emsg(_(e_noident));
      }
      return 0;
    }
    ptr += col;
    *text = ptr;
    if (textcol != NULL) {
      *textcol = col;
    }
  
    // 3. Find the end if the identifier/text.
    bn = 0;
    startcol -= col;
    col = 0;
    // Search for point of changing multibyte character class.
    this_class = mb_get_class(ptr);
    while (ptr[col] != NUL
           && ((i == 0
                ? mb_get_class(ptr + col) == this_class
                : mb_get_class(ptr + col) != 0)
               || ((find_type & FIND_EVAL)
                   && col <= (int)startcol
                   && find_is_eval_item(ptr + col, &col, &bn, FORWARD)))) {
      col += utfc_ptr2len(ptr + col);
    }
  
    assert(col >= 0);
    return (size_t)col;
  }
  
  /*
   * Prepare for redo of a normal command.
   */
  static void prep_redo_cmd(cmdarg_T *cap)
  {
    prep_redo(cap->oap->regname, cap->count0,
              NUL, cap->cmdchar, NUL, NUL, cap->nchar);
  }
  
  /*
   * Prepare for redo of any command.
   * Note that only the last argument can be a multi-byte char.
   */
  static void prep_redo(int regname, long num, int cmd1, int cmd2, int cmd3, int cmd4, int cmd5)
  {
    ResetRedobuff();
    if (regname != 0) {   // yank from specified buffer
      AppendCharToRedobuff('"');
      AppendCharToRedobuff(regname);
    }
    if (num) {
      AppendNumberToRedobuff(num);
    }
  
    if (cmd1 != NUL) {
      AppendCharToRedobuff(cmd1);
    }
    if (cmd2 != NUL) {
      AppendCharToRedobuff(cmd2);
    }
    if (cmd3 != NUL) {
      AppendCharToRedobuff(cmd3);
    }
    if (cmd4 != NUL) {
      AppendCharToRedobuff(cmd4);
    }
    if (cmd5 != NUL) {
      AppendCharToRedobuff(cmd5);
    }
  }
  
  /*
   * check for operator active and clear it
   *
   * return true if operator was active
   */
  static bool checkclearop(oparg_T *oap)
  {
    if (oap->op_type == OP_NOP) {
      return false;
    }
    clearopbeep(oap);
    return true;
  }
  
  /*
   * Check for operator or Visual active.  Clear active operator.
   *
   * Return true if operator or Visual was active.
   */
  static bool checkclearopq(oparg_T *oap)
  {
    if (oap->op_type == OP_NOP
        && !VIsual_active) {
      return false;
    }
    clearopbeep(oap);
    return true;
  }
  
  static void clearop(oparg_T *oap)
  {
    oap->op_type = OP_NOP;
    oap->regname = 0;
    oap->motion_force = NUL;
    oap->use_reg_one = false;
    motion_force = NUL;
  }
  
  static void clearopbeep(oparg_T *oap)
  {
    clearop(oap);
    beep_flush();
  }
  
  /*
   * Remove the shift modifier from a special key.
   */
  static void unshift_special(cmdarg_T *cap)
  {
    switch (cap->cmdchar) {
    case K_S_RIGHT:
      cap->cmdchar = K_RIGHT; break;
    case K_S_LEFT:
      cap->cmdchar = K_LEFT; break;
    case K_S_UP:
      cap->cmdchar = K_UP; break;
    case K_S_DOWN:
      cap->cmdchar = K_DOWN; break;
    case K_S_HOME:
      cap->cmdchar = K_HOME; break;
    case K_S_END:
      cap->cmdchar = K_END; break;
    }
    cap->cmdchar = simplify_key(cap->cmdchar, &mod_mask);
  }
  
  /// If the mode is currently displayed clear the command line or update the
  /// command displayed.
  static void may_clear_cmdline(void)
  {
    if (mode_displayed) {
      // unshow visual mode later
      clear_cmdline = true;
    } else {
      clear_showcmd();
    }
  }
  
  // Routines for displaying a partly typed command
  #define SHOWCMD_BUFLEN SHOWCMD_COLS + 1 + 30
  static char_u showcmd_buf[SHOWCMD_BUFLEN];
  static char_u old_showcmd_buf[SHOWCMD_BUFLEN];    // For push_showcmd()
  static bool showcmd_is_clear = true;
  static bool showcmd_visual = false;
  
  
  void clear_showcmd(void)
  {
    if (!p_sc) {
      return;
    }
  
    if (VIsual_active && !char_avail()) {
      int cursor_bot = lt(VIsual, curwin->w_cursor);
      long lines;
      colnr_T leftcol, rightcol;
      linenr_T top, bot;
  
      // Show the size of the Visual area.
      if (cursor_bot) {
        top = VIsual.lnum;
        bot = curwin->w_cursor.lnum;
      } else {
        top = curwin->w_cursor.lnum;
        bot = VIsual.lnum;
      }
      // Include closed folds as a whole.
      (void)hasFolding(top, &top, NULL);
      (void)hasFolding(bot, NULL, &bot);
      lines = bot - top + 1;
  
      if (VIsual_mode == Ctrl_V) {
        char_u *const saved_sbr = p_sbr;
        char_u *const saved_w_sbr = curwin->w_p_sbr;
  
        // Make 'sbr' empty for a moment to get the correct size.
        p_sbr = empty_option;
        curwin->w_p_sbr = empty_option;
        getvcols(curwin, &curwin->w_cursor, &VIsual, &leftcol, &rightcol);
        p_sbr = saved_sbr;
        curwin->w_p_sbr = saved_w_sbr;
        snprintf((char *)showcmd_buf, SHOWCMD_BUFLEN, "%" PRId64 "x%" PRId64,
                 (int64_t)lines, (int64_t)rightcol - leftcol + 1);
      } else if (VIsual_mode == 'V' || VIsual.lnum != curwin->w_cursor.lnum) {
        snprintf((char *)showcmd_buf, SHOWCMD_BUFLEN, "%" PRId64, (int64_t)lines);
      } else {
        char_u *s, *e;
        int l;
        int bytes = 0;
        int chars = 0;
  
        if (cursor_bot) {
          s = ml_get_pos(&VIsual);
          e = get_cursor_pos_ptr();
        } else {
          s = get_cursor_pos_ptr();
          e = ml_get_pos(&VIsual);
        }
        while ((*p_sel != 'e') ? s <= e : s < e) {
          l = utfc_ptr2len(s);
          if (l == 0) {
            ++bytes;
            ++chars;
            break;            // end of line
          }
          bytes += l;
          ++chars;
          s += l;
        }
        if (bytes == chars) {
          sprintf((char *)showcmd_buf, "%d", chars);
        } else {
          sprintf((char *)showcmd_buf, "%d-%d", chars, bytes);
        }
      }
      int limit = ui_has(kUIMessages) ? SHOWCMD_BUFLEN-1 : SHOWCMD_COLS;
      showcmd_buf[limit] = NUL;  // truncate
      showcmd_visual = true;
    } else {
      showcmd_buf[0] = NUL;
      showcmd_visual = false;
  
      // Don't actually display something if there is nothing to clear.
      if (showcmd_is_clear) {
        return;
      }
    }
  
    display_showcmd();
  }
  
  /*
   * Add 'c' to string of shown command chars.
   * Return true if output has been written (and setcursor() has been called).
   */
  bool add_to_showcmd(int c)
  {
    char_u *p;
    int i;
    static int ignore[] =
    {
      K_IGNORE,
      K_LEFTMOUSE, K_LEFTDRAG, K_LEFTRELEASE, K_MOUSEMOVE,
      K_MIDDLEMOUSE, K_MIDDLEDRAG, K_MIDDLERELEASE,
      K_RIGHTMOUSE, K_RIGHTDRAG, K_RIGHTRELEASE,
      K_MOUSEDOWN, K_MOUSEUP, K_MOUSELEFT, K_MOUSERIGHT,
      K_X1MOUSE, K_X1DRAG, K_X1RELEASE, K_X2MOUSE, K_X2DRAG, K_X2RELEASE,
      K_EVENT,
      0
    };
  
    if (!p_sc || msg_silent != 0) {
      return false;
    }
  
    if (showcmd_visual) {
      showcmd_buf[0] = NUL;
      showcmd_visual = false;
    }
  
    // Ignore keys that are scrollbar updates and mouse clicks
    if (IS_SPECIAL(c)) {
      for (i = 0; ignore[i] != 0; ++i) {
        if (ignore[i] == c) {
          return false;
        }
      }
    }
  
    p = transchar(c);
    if (*p == ' ') {
      STRCPY(p, "<20>");
    }
    size_t old_len = STRLEN(showcmd_buf);
    size_t extra_len = STRLEN(p);
    size_t limit = ui_has(kUIMessages) ? SHOWCMD_BUFLEN-1 : SHOWCMD_COLS;
    if (old_len + extra_len > limit) {
      size_t overflow = old_len + extra_len - limit;
      memmove(showcmd_buf, showcmd_buf + overflow, old_len - overflow + 1);
    }
    STRCAT(showcmd_buf, p);
  
    if (char_avail()) {
      return false;
    }
  
    display_showcmd();
  
    return true;
  }
  
  void add_to_showcmd_c(int c)
  {
    add_to_showcmd(c);
    setcursor();
  }
  
  /*
   * Delete 'len' characters from the end of the shown command.
   */
  static void del_from_showcmd(int len)
  {
    int old_len;
  
    if (!p_sc) {
      return;
    }
  
    old_len = (int)STRLEN(showcmd_buf);
    if (len > old_len) {
      len = old_len;
    }
    showcmd_buf[old_len - len] = NUL;
  
    if (!char_avail()) {
      display_showcmd();
    }
  }
  
  /*
   * push_showcmd() and pop_showcmd() are used when waiting for the user to type
   * something and there is a partial mapping.
   */
  void push_showcmd(void)
  {
    if (p_sc) {
      STRCPY(old_showcmd_buf, showcmd_buf);
    }
  }
  
  void pop_showcmd(void)
  {
    if (!p_sc) {
      return;
    }
  
    STRCPY(showcmd_buf, old_showcmd_buf);
  
    display_showcmd();
  }
  
  static void display_showcmd(void)
  {
    int len;
    len = (int)STRLEN(showcmd_buf);
    showcmd_is_clear = (len == 0);
  
    if (ui_has(kUIMessages)) {
      Array content = ARRAY_DICT_INIT;
      if (len > 0) {
        Array chunk = ARRAY_DICT_INIT;
        // placeholder for future highlight support
        ADD(chunk, INTEGER_OBJ(0));
        ADD(chunk, STRING_OBJ(cstr_to_string((char *)showcmd_buf)));
        ADD(content, ARRAY_OBJ(chunk));
      }
      ui_call_msg_showcmd(content);
      return;
    }
  
    msg_grid_validate();
    int showcmd_row = Rows - 1;
    grid_puts_line_start(&msg_grid_adj, showcmd_row);
  
    if (!showcmd_is_clear) {
      grid_puts(&msg_grid_adj, showcmd_buf, showcmd_row, sc_col,
                HL_ATTR(HLF_MSG));
    }
  
    // clear the rest of an old message by outputting up to SHOWCMD_COLS spaces
    grid_puts(&msg_grid_adj, (char_u *)"          " + len, showcmd_row,
              sc_col + len, HL_ATTR(HLF_MSG));
  
    grid_puts_line_flush(false);
  }
  
  /*
   * When "check" is false, prepare for commands that scroll the window.
   * When "check" is true, take care of scroll-binding after the window has
   * scrolled.  Called from normal_cmd() and edit().
   */
  void do_check_scrollbind(bool check)
  {
    static win_T *old_curwin = NULL;
    static linenr_T old_topline = 0;
    static int old_topfill = 0;
    static buf_T *old_buf = NULL;
    static colnr_T old_leftcol = 0;
  
    if (check && curwin->w_p_scb) {
      // If a ":syncbind" command was just used, don't scroll, only reset
      // the values.
      if (did_syncbind) {
        did_syncbind = false;
      } else if (curwin == old_curwin) {
        /*
         * Synchronize other windows, as necessary according to
         * 'scrollbind'.  Don't do this after an ":edit" command, except
         * when 'diff' is set.
         */
        if ((curwin->w_buffer == old_buf
             || curwin->w_p_diff
             )
            && (curwin->w_topline != old_topline
                || curwin->w_topfill != old_topfill
                || curwin->w_leftcol != old_leftcol)) {
          check_scrollbind(curwin->w_topline - old_topline,
                           (long)(curwin->w_leftcol - old_leftcol));
        }
      } else if (vim_strchr(p_sbo, 'j')) {  // jump flag set in 'scrollopt'
        /*
         * When switching between windows, make sure that the relative
         * vertical offset is valid for the new window.  The relative
         * offset is invalid whenever another 'scrollbind' window has
         * scrolled to a point that would force the current window to
         * scroll past the beginning or end of its buffer.  When the
         * resync is performed, some of the other 'scrollbind' windows may
         * need to jump so that the current window's relative position is
         * visible on-screen.
         */
        check_scrollbind(curwin->w_topline - curwin->w_scbind_pos, 0L);
      }
      curwin->w_scbind_pos = curwin->w_topline;
    }
  
    old_curwin = curwin;
    old_topline = curwin->w_topline;
    old_topfill = curwin->w_topfill;
    old_buf = curwin->w_buffer;
    old_leftcol = curwin->w_leftcol;
  }
  
  /*
   * Synchronize any windows that have "scrollbind" set, based on the
   * number of rows by which the current window has changed
   * (1998-11-02 16:21:01  R. Edward Ralston <eralston@computer.org>)
   */
  void check_scrollbind(linenr_T topline_diff, long leftcol_diff)
  {
    bool want_ver;
    bool want_hor;
    win_T *old_curwin = curwin;
    buf_T *old_curbuf = curbuf;
    int old_VIsual_select = VIsual_select;
    int old_VIsual_active = VIsual_active;
    colnr_T tgt_leftcol = curwin->w_leftcol;
    long topline;
    long y;
  
    /*
     * check 'scrollopt' string for vertical and horizontal scroll options
     */
    want_ver = (vim_strchr(p_sbo, 'v') && topline_diff != 0);
    want_ver |= old_curwin->w_p_diff;
    want_hor = (vim_strchr(p_sbo, 'h') && (leftcol_diff || topline_diff != 0));
  
    /*
     * loop through the scrollbound windows and scroll accordingly
     */
    VIsual_select = VIsual_active = 0;
    FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
      curwin = wp;
      curbuf = curwin->w_buffer;
      // skip original window  and windows with 'noscrollbind'
      if (curwin == old_curwin || !curwin->w_p_scb) {
        continue;
      }
      /*
       * do the vertical scroll
       */
      if (want_ver) {
        if (old_curwin->w_p_diff && curwin->w_p_diff) {
          diff_set_topline(old_curwin, curwin);
        } else {
          curwin->w_scbind_pos += topline_diff;
          topline = curwin->w_scbind_pos;
          if (topline > curbuf->b_ml.ml_line_count) {
            topline = curbuf->b_ml.ml_line_count;
          }
          if (topline < 1) {
            topline = 1;
          }
  
          y = topline - curwin->w_topline;
          if (y > 0) {
            scrollup(y, false);
          } else {
            scrolldown(-y, false);
          }
        }
  
        redraw_later(curwin, VALID);
        cursor_correct();
        curwin->w_redr_status = true;
      }
  
      /*
       * do the horizontal scroll
       */
      if (want_hor && curwin->w_leftcol != tgt_leftcol) {
        curwin->w_leftcol = tgt_leftcol;
        leftcol_changed();
      }
    }
  
    /*
     * reset current-window
     */
    VIsual_select = old_VIsual_select;
    VIsual_active = old_VIsual_active;
    curwin = old_curwin;
    curbuf = old_curbuf;
  }
  
  /*
   * Command character that's ignored.
   * Used for CTRL-Q and CTRL-S to avoid problems with terminals that use
   * xon/xoff.
   */
  static void nv_ignore(cmdarg_T *cap)
  {
    cap->retval |= CA_COMMAND_BUSY;       // don't call edit() now
  }
  
  /*
   * Command character that doesn't do anything, but unlike nv_ignore() does
   * start edit().  Used for "startinsert" executed while starting up.
   */
  static void nv_nop(cmdarg_T *cap)
  {
  }
  
  /*
   * Command character doesn't exist.
   */
  static void nv_error(cmdarg_T *cap)
  {
    clearopbeep(cap->oap);
  }
  
  /*
   * <Help> and <F1> commands.
   */
  static void nv_help(cmdarg_T *cap)
  {
    if (!checkclearopq(cap->oap)) {
      ex_help(NULL);
    }
  }
  
  /*
   * CTRL-A and CTRL-X: Add or subtract from letter or number under cursor.
   */
  static void nv_addsub(cmdarg_T *cap)
  {
    if (bt_prompt(curbuf) && !prompt_curpos_editable()) {
      clearopbeep(cap->oap);
    } else if (!VIsual_active && cap->oap->op_type == OP_NOP) {
      prep_redo_cmd(cap);
      cap->oap->op_type = cap->cmdchar == Ctrl_A ? OP_NR_ADD : OP_NR_SUB;
      op_addsub(cap->oap, cap->count1, cap->arg);
      cap->oap->op_type = OP_NOP;
    } else if (VIsual_active) {
      nv_operator(cap);
    } else {
      clearop(cap->oap);
    }
  }
  
  /*
   * CTRL-F, CTRL-B, etc: Scroll page up or down.
   */
  static void nv_page(cmdarg_T *cap)
  {
    if (!checkclearop(cap->oap)) {
      if (mod_mask & MOD_MASK_CTRL) {
        // <C-PageUp>: tab page back; <C-PageDown>: tab page forward
        if (cap->arg == BACKWARD) {
          goto_tabpage(-(int)cap->count1);
        } else {
          goto_tabpage((int)cap->count0);
        }
      } else {
        (void)onepage(cap->arg, cap->count1);
      }
    }
  }
  
  /// Implementation of "gd" and "gD" command.
  ///
  /// @param thisblock  1 for "1gd" and "1gD"
  static void nv_gd(oparg_T *oap, int nchar, int thisblock)
  {
    size_t len;
    char_u *ptr;
    if ((len = find_ident_under_cursor(&ptr, FIND_IDENT)) == 0
        || !find_decl(ptr, len, nchar == 'd', thisblock, SEARCH_START)) {
      clearopbeep(oap);
    } else if ((fdo_flags & FDO_SEARCH) && KeyTyped && oap->op_type == OP_NOP) {
      foldOpenCursor();
    }
  }
  
  // Return true if line[offset] is not inside a C-style comment or string, false
  // otherwise.
  static bool is_ident(char_u *line, int offset)
  {
    bool incomment = false;
    int instring = 0;
    int prev = 0;
  
    for (int i = 0; i < offset && line[i] != NUL; i++) {
      if (instring != 0) {
        if (prev != '\\' && line[i] == instring) {
          instring = 0;
        }
      } else if ((line[i] == '"' || line[i] == '\'') && !incomment) {
        instring = line[i];
      } else {
        if (incomment) {
          if (prev == '*' && line[i] == '/') {
            incomment = false;
          }
        } else if (prev == '/' && line[i] == '*') {
          incomment = true;
        } else if (prev == '/' && line[i] == '/') {
          return false;
        }
      }
  
      prev = line[i];
    }
  
    return incomment == false && instring == 0;
  }
  
  /// Search for variable declaration of "ptr[len]".
  /// When "locally" is true in the current function ("gd"), otherwise in the
  /// current file ("gD").
  ///
  /// @param thisblock  when true check the {} block scope.
  /// @param flags_arg  flags passed to searchit()
  ///
  /// @return           fail when not found.
  bool find_decl(char_u *ptr, size_t len, bool locally, bool thisblock, int flags_arg)
  {
    char_u *pat;
    pos_T old_pos;
    pos_T par_pos;
    pos_T found_pos;
    bool t;
    bool save_p_ws;
    bool save_p_scs;
    bool retval = true;
    bool incll;
    int searchflags = flags_arg;
  
    pat = xmalloc(len + 7);
  
    // Put "\V" before the pattern to avoid that the special meaning of "."
    // and "~" causes trouble.
    assert(len <= INT_MAX);
    sprintf((char *)pat, vim_iswordp(ptr) ? "\\V\\<%.*s\\>" : "\\V%.*s",
            (int)len, ptr);
    old_pos = curwin->w_cursor;
    save_p_ws = p_ws;
    save_p_scs = p_scs;
    p_ws = false;         // don't wrap around end of file now
    p_scs = false;        // don't switch ignorecase off now
  
    /*
     * With "gD" go to line 1.
     * With "gd" Search back for the start of the current function, then go
     * back until a blank line.  If this fails go to line 1.
     */
    if (!locally || !findpar(&incll, BACKWARD, 1L, '{', false)) {
      setpcmark();                        // Set in findpar() otherwise
      curwin->w_cursor.lnum = 1;
      par_pos = curwin->w_cursor;
    } else {
      par_pos = curwin->w_cursor;
      while (curwin->w_cursor.lnum > 1
             && *skipwhite(get_cursor_line_ptr()) != NUL) {
        --curwin->w_cursor.lnum;
      }
    }
    curwin->w_cursor.col = 0;
  
    // Search forward for the identifier, ignore comment lines.
    clearpos(&found_pos);
    for (;;) {
      t = searchit(curwin, curbuf, &curwin->w_cursor, NULL, FORWARD,
                   pat, 1L, searchflags, RE_LAST, NULL);
      if (curwin->w_cursor.lnum >= old_pos.lnum) {
        t = false;         // match after start is failure too
      }
  
      if (thisblock && t != false) {
        const int64_t maxtravel = old_pos.lnum - curwin->w_cursor.lnum + 1;
        const pos_T *pos = findmatchlimit(NULL, '}', FM_FORWARD, maxtravel);
  
        // Check that the block the match is in doesn't end before the
        // position where we started the search from.
        if (pos != NULL && pos->lnum < old_pos.lnum) {
          // There can't be a useful match before the end of this block.
          // Skip to the end
          curwin->w_cursor = *pos;
          continue;
        }
      }
  
      if (t == false) {
        // If we previously found a valid position, use it.
        if (found_pos.lnum != 0) {
          curwin->w_cursor = found_pos;
          t = true;
        }
        break;
      }
      if (get_leader_len(get_cursor_line_ptr(), NULL, false, true) > 0) {
        // Ignore this line, continue at start of next line.
        ++curwin->w_cursor.lnum;
        curwin->w_cursor.col = 0;
        continue;
      }
      bool valid = is_ident(get_cursor_line_ptr(), curwin->w_cursor.col);
  
      // If the current position is not a valid identifier and a previous match is
      // present, favor that one instead.
      if (!valid && found_pos.lnum != 0) {
        curwin->w_cursor = found_pos;
        break;
      }
      // global search: use first match found
      if (valid && !locally) {
        break;
      }
      if (valid && curwin->w_cursor.lnum >= par_pos.lnum) {
        // If we previously found a valid position, use it.
        if (found_pos.lnum != 0) {
          curwin->w_cursor = found_pos;
        }
        break;
      }
  
      // For finding a local variable and the match is before the "{" or
      // inside a comment, continue searching.  For K&R style function
      // declarations this skips the function header without types.
      if (!valid) {
        clearpos(&found_pos);
      } else {
        found_pos = curwin->w_cursor;
      }
      // Remove SEARCH_START from flags to avoid getting stuck at one position.
      searchflags &= ~SEARCH_START;
    }
  
    if (t == false) {
      retval = false;
      curwin->w_cursor = old_pos;
    } else {
      curwin->w_set_curswant = true;
      // "n" searches forward now
      reset_search_dir();
    }
  
    xfree(pat);
    p_ws = save_p_ws;
    p_scs = save_p_scs;
  
    return retval;
  }
  
  /*
   * Move 'dist' lines in direction 'dir', counting lines by *screen*
   * lines rather than lines in the file.
   * 'dist' must be positive.
   *
   * Return true if able to move cursor, false otherwise.
   */
  static bool nv_screengo(oparg_T *oap, int dir, long dist)
  {
    int linelen = linetabsize(get_cursor_line_ptr());
    bool retval = true;
    bool atend = false;
    int n;
    int col_off1;                 // margin offset for first screen line
    int col_off2;                 // margin offset for wrapped screen line
    int width1;                   // text width for first screen line
    int width2;                   // test width for wrapped screen line
  
    oap->motion_type = kMTCharWise;
    oap->inclusive = (curwin->w_curswant == MAXCOL);
  
    col_off1 = curwin_col_off();
    col_off2 = col_off1 - curwin_col_off2();
    width1 = curwin->w_width_inner - col_off1;
    width2 = curwin->w_width_inner - col_off2;
  
    if (width2 == 0) {
      width2 = 1;  // Avoid divide by zero.
    }
  
    if (curwin->w_width_inner != 0) {
      // Instead of sticking at the last character of the buffer line we
      // try to stick in the last column of the screen.
      if (curwin->w_curswant == MAXCOL) {
        atend = true;
        validate_virtcol();
        if (width1 <= 0) {
          curwin->w_curswant = 0;
        } else {
          curwin->w_curswant = width1 - 1;
          if (curwin->w_virtcol > curwin->w_curswant) {
            curwin->w_curswant += ((curwin->w_virtcol
                                    - curwin->w_curswant -
                                    1) / width2 + 1) * width2;
          }
        }
      } else {
        if (linelen > width1) {
          n = ((linelen - width1 - 1) / width2 + 1) * width2 + width1;
        } else {
          n = width1;
        }
        if (curwin->w_curswant >= n) {
          curwin->w_curswant = n - 1;
        }
      }
  
      while (dist--) {
        if (dir == BACKWARD) {
          if (curwin->w_curswant >= width1
              && !hasFolding(curwin->w_cursor.lnum, NULL, NULL)) {
            // Move back within the line. This can give a negative value
            // for w_curswant if width1 < width2 (with cpoptions+=n),
            // which will get clipped to column 0.
            curwin->w_curswant -= width2;
          } else {
            // to previous line
  
            // Move to the start of a closed fold.  Don't do that when
            // 'foldopen' contains "all": it will open in a moment.
            if (!(fdo_flags & FDO_ALL)) {
              (void)hasFolding(curwin->w_cursor.lnum,
                               &curwin->w_cursor.lnum, NULL);
            }
            if (curwin->w_cursor.lnum == 1) {
              retval = false;
              break;
            }
            curwin->w_cursor.lnum--;
  
            linelen = linetabsize(get_cursor_line_ptr());
            if (linelen > width1) {
              int w = (((linelen - width1 - 1) / width2) + 1) * width2;
              assert(curwin->w_curswant <= INT_MAX - w);
              curwin->w_curswant += w;
            }
          }
        } else {  // dir == FORWARD
          if (linelen > width1) {
            n = ((linelen - width1 - 1) / width2 + 1) * width2 + width1;
          } else {
            n = width1;
          }
          if (curwin->w_curswant + width2 < (colnr_T)n
              && !hasFolding(curwin->w_cursor.lnum, NULL, NULL)) {
            // move forward within line
            curwin->w_curswant += width2;
          } else {
            // to next line
  
            // Move to the end of a closed fold.
            (void)hasFolding(curwin->w_cursor.lnum, NULL,
                             &curwin->w_cursor.lnum);
            if (curwin->w_cursor.lnum == curbuf->b_ml.ml_line_count) {
              retval = false;
              break;
            }
            curwin->w_cursor.lnum++;
            curwin->w_curswant %= width2;
            // Check if the cursor has moved below the number display
            // when width1 < width2 (with cpoptions+=n). Subtract width2
            // to get a negative value for w_curswant, which will get
            // clipped to column 0.
            if (curwin->w_curswant >= width1) {
              curwin->w_curswant -= width2;
            }
            linelen = linetabsize(get_cursor_line_ptr());
          }
        }
      }
    }
  
    if (virtual_active() && atend) {
      coladvance(MAXCOL);
    } else {
      coladvance(curwin->w_curswant);
    }
  
    if (curwin->w_cursor.col > 0 && curwin->w_p_wrap) {
      /*
       * Check for landing on a character that got split at the end of the
       * last line.  We want to advance a screenline, not end up in the same
       * screenline or move two screenlines.
       */
      validate_virtcol();
      colnr_T virtcol = curwin->w_virtcol;
      if (virtcol > (colnr_T)width1 && *get_showbreak_value(curwin) != NUL) {
        virtcol -= vim_strsize(get_showbreak_value(curwin));
      }
  
      if (virtcol > curwin->w_curswant
          && (curwin->w_curswant < (colnr_T)width1
              ? (curwin->w_curswant > (colnr_T)width1 / 2)
              : ((curwin->w_curswant - width1) % width2
                 > (colnr_T)width2 / 2))) {
        --curwin->w_cursor.col;
      }
    }
  
    if (atend) {
      curwin->w_curswant = MAXCOL;            // stick in the last column
    }
    return retval;
  }
  
  /*
   * Mouse scroll wheel: Default action is to scroll three lines, or one page
   * when Shift or Ctrl is used.
   * K_MOUSEUP (cap->arg == 1) or K_MOUSEDOWN (cap->arg == 0) or
   * K_MOUSELEFT (cap->arg == -1) or K_MOUSERIGHT (cap->arg == -2)
   */
  static void nv_mousescroll(cmdarg_T *cap)
  {
    win_T *old_curwin = curwin;
  
    if (mouse_row >= 0 && mouse_col >= 0) {
      int grid, row, col;
  
      grid = mouse_grid;
      row = mouse_row;
      col = mouse_col;
  
      // find the window at the pointer coordinates
      win_T *wp = mouse_find_win(&grid, &row, &col);
      if (wp == NULL) {
        return;
      }
      curwin = wp;
      curbuf = curwin->w_buffer;
    }
  
    if (cap->arg == MSCR_UP || cap->arg == MSCR_DOWN) {
      if (mod_mask & (MOD_MASK_SHIFT | MOD_MASK_CTRL)) {
        (void)onepage(cap->arg ? FORWARD : BACKWARD, 1L);
      } else {
        cap->count1 = 3;
        cap->count0 = 3;
        nv_scroll_line(cap);
      }
    } else {
      mouse_scroll_horiz(cap->arg);
    }
    if (curwin != old_curwin && curwin->w_p_cul) {
      redraw_for_cursorline(curwin);
    }
  
    curwin->w_redr_status = true;
  
    curwin = old_curwin;
    curbuf = curwin->w_buffer;
  }
  
  /*
   * Mouse clicks and drags.
   */
  static void nv_mouse(cmdarg_T *cap)
  {
    (void)do_mouse(cap->oap, cap->cmdchar, BACKWARD, cap->count1, 0);
  }
  
  /*
   * Handle CTRL-E and CTRL-Y commands: scroll a line up or down.
   * cap->arg must be true for CTRL-E.
   */
  static void nv_scroll_line(cmdarg_T *cap)
  {
    if (!checkclearop(cap->oap)) {
      scroll_redraw(cap->arg, cap->count1);
    }
  }
  
  /*
   * Scroll "count" lines up or down, and redraw.
   */
  void scroll_redraw(int up, long count)
  {
    linenr_T prev_topline = curwin->w_topline;
    int prev_topfill = curwin->w_topfill;
    linenr_T prev_lnum = curwin->w_cursor.lnum;
  
    bool moved = up ?
                 scrollup(count, true) :
                 scrolldown(count, true);
  
    if (get_scrolloff_value(curwin)) {
      // Adjust the cursor position for 'scrolloff'.  Mark w_topline as
      // valid, otherwise the screen jumps back at the end of the file.
      cursor_correct();
      check_cursor_moved(curwin);
      curwin->w_valid |= VALID_TOPLINE;
  
      // If moved back to where we were, at least move the cursor, otherwise
      // we get stuck at one position.  Don't move the cursor up if the
      // first line of the buffer is already on the screen
      while (curwin->w_topline == prev_topline
             && curwin->w_topfill == prev_topfill) {
        if (up) {
          if (curwin->w_cursor.lnum > prev_lnum
              || cursor_down(1L, false) == false) {
            break;
          }
        } else {
          if (curwin->w_cursor.lnum < prev_lnum
              || prev_topline == 1L
              || cursor_up(1L, false) == false) {
            break;
          }
        }
        // Mark w_topline as valid, otherwise the screen jumps back at the
        // end of the file.
        check_cursor_moved(curwin);
        curwin->w_valid |= VALID_TOPLINE;
      }
    }
    if (curwin->w_cursor.lnum != prev_lnum) {
      coladvance(curwin->w_curswant);
    }
    if (moved) {
      curwin->w_viewport_invalid = true;
    }
    redraw_later(curwin, VALID);
  }
  
  /*
   * Commands that start with "z".
   */
  static void nv_zet(cmdarg_T *cap)
  {
    int n;
    colnr_T col;
    int nchar = cap->nchar;
    long old_fdl = curwin->w_p_fdl;
    int old_fen = curwin->w_p_fen;
    bool undo = false;
  
    int l_p_siso = (int)get_sidescrolloff_value(curwin);
    assert(l_p_siso <= INT_MAX);
  
    if (ascii_isdigit(nchar)) {
      /*
       * "z123{nchar}": edit the count before obtaining {nchar}
       */
      if (checkclearop(cap->oap)) {
        return;
      }
      n = nchar - '0';
      for (;;) {
        no_mapping++;
        nchar = plain_vgetc();
        LANGMAP_ADJUST(nchar, true);
        no_mapping--;
        (void)add_to_showcmd(nchar);
        if (nchar == K_DEL || nchar == K_KDEL) {
          n /= 10;
        } else if (ascii_isdigit(nchar)) {
          n = n * 10 + (nchar - '0');
        } else if (nchar == CAR) {
          win_setheight(n);
          break;
        } else if (nchar == 'l'
                   || nchar == 'h'
                   || nchar == K_LEFT
                   || nchar == K_RIGHT) {
          cap->count1 = n ? n * cap->count1 : cap->count1;
          goto dozet;
        } else {
          clearopbeep(cap->oap);
          break;
        }
      }
      cap->oap->op_type = OP_NOP;
      return;
    }
  
  dozet:
    // "zf" and "zF" are always an operator, "zd", "zo", "zO", "zc"
    // and "zC" only in Visual mode.  "zj" and "zk" are motion
    // commands.
    if (cap->nchar != 'f' && cap->nchar != 'F'
        && !(VIsual_active && vim_strchr((char_u *)"dcCoO", cap->nchar))
        && cap->nchar != 'j' && cap->nchar != 'k'
        && checkclearop(cap->oap)) {
      return;
    }
  
    /*
     * For "z+", "z<CR>", "zt", "z.", "zz", "z^", "z-", "zb":
     * If line number given, set cursor.
     */
    if ((vim_strchr((char_u *)"+\r\nt.z^-b", nchar) != NULL)
        && cap->count0
        && cap->count0 != curwin->w_cursor.lnum) {
      setpcmark();
      if (cap->count0 > curbuf->b_ml.ml_line_count) {
        curwin->w_cursor.lnum = curbuf->b_ml.ml_line_count;
      } else {
        curwin->w_cursor.lnum = cap->count0;
      }
      check_cursor_col();
    }
  
    switch (nchar) {
    // "z+", "z<CR>" and "zt": put cursor at top of screen
    case '+':
      if (cap->count0 == 0) {
        // No count given: put cursor at the line below screen
        validate_botline(curwin);               // make sure w_botline is valid
        if (curwin->w_botline > curbuf->b_ml.ml_line_count) {
          curwin->w_cursor.lnum = curbuf->b_ml.ml_line_count;
        } else {
          curwin->w_cursor.lnum = curwin->w_botline;
        }
      }
      FALLTHROUGH;
    case NL:
    case CAR:
    case K_KENTER:
      beginline(BL_WHITE | BL_FIX);
      FALLTHROUGH;
  
    case 't':
      scroll_cursor_top(0, true);
      redraw_later(curwin, VALID);
      set_fraction(curwin);
      break;
  
    // "z." and "zz": put cursor in middle of screen
    case '.':
      beginline(BL_WHITE | BL_FIX);
      FALLTHROUGH;
  
    case 'z':
      scroll_cursor_halfway(true);
      redraw_later(curwin, VALID);
      set_fraction(curwin);
      break;
  
    // "z^", "z-" and "zb": put cursor at bottom of screen
    case '^':     // Strange Vi behavior: <count>z^ finds line at top of window
                  // when <count> is at bottom of window, and puts that one at
                  // bottom of window.
      if (cap->count0 != 0) {
        scroll_cursor_bot(0, true);
        curwin->w_cursor.lnum = curwin->w_topline;
      } else if (curwin->w_topline == 1) {
        curwin->w_cursor.lnum = 1;
      } else {
        curwin->w_cursor.lnum = curwin->w_topline - 1;
      }
      FALLTHROUGH;
    case '-':
      beginline(BL_WHITE | BL_FIX);
      FALLTHROUGH;
  
    case 'b':
      scroll_cursor_bot(0, true);
      redraw_later(curwin, VALID);
      set_fraction(curwin);
      break;
  
    // "zH" - scroll screen right half-page
    case 'H':
      cap->count1 *= curwin->w_width_inner / 2;
      FALLTHROUGH;
  
    // "zh" - scroll screen to the right
    case 'h':
    case K_LEFT:
      if (!curwin->w_p_wrap) {
        if ((colnr_T)cap->count1 > curwin->w_leftcol) {
          curwin->w_leftcol = 0;
        } else {
          curwin->w_leftcol -= (colnr_T)cap->count1;
        }
        leftcol_changed();
      }
      break;
  
    // "zL" - scroll screen left half-page
    case 'L':
      cap->count1 *= curwin->w_width_inner / 2;
      FALLTHROUGH;
  
    // "zl" - scroll screen to the left
    case 'l':
    case K_RIGHT:
      if (!curwin->w_p_wrap) {
        // scroll the window left
        curwin->w_leftcol += (colnr_T)cap->count1;
        leftcol_changed();
      }
      break;
  
    // "zs" - scroll screen, cursor at the start
    case 's':
      if (!curwin->w_p_wrap) {
        if (hasFolding(curwin->w_cursor.lnum, NULL, NULL)) {
          col = 0;                        // like the cursor is in col 0
        } else {
          getvcol(curwin, &curwin->w_cursor, &col, NULL, NULL);
        }
        if (col > l_p_siso) {
          col -= l_p_siso;
        } else {
          col = 0;
        }
        if (curwin->w_leftcol != col) {
          curwin->w_leftcol = col;
          redraw_later(curwin, NOT_VALID);
        }
      }
      break;
  
    // "ze" - scroll screen, cursor at the end
    case 'e':
      if (!curwin->w_p_wrap) {
        if (hasFolding(curwin->w_cursor.lnum, NULL, NULL)) {
          col = 0;                        // like the cursor is in col 0
        } else {
          getvcol(curwin, &curwin->w_cursor, NULL, NULL, &col);
        }
        n = curwin->w_width_inner - curwin_col_off();
        if (col + l_p_siso < n) {
          col = 0;
        } else {
          col = col + l_p_siso - n + 1;
        }
        if (curwin->w_leftcol != col) {
          curwin->w_leftcol = col;
          redraw_later(curwin, NOT_VALID);
        }
      }
      break;
  
    // "zp", "zP" in block mode put without addind trailing spaces
    case 'P':
    case 'p':
      nv_put(cap);
      break;
    // "zy" Yank without trailing spaces
    case 'y':
      nv_operator(cap);
      break;
  
    // "zF": create fold command
    // "zf": create fold operator
    case 'F':
    case 'f':
      if (foldManualAllowed(true)) {
        cap->nchar = 'f';
        nv_operator(cap);
        curwin->w_p_fen = true;
  
        // "zF" is like "zfzf"
        if (nchar == 'F' && cap->oap->op_type == OP_FOLD) {
          nv_operator(cap);
          finish_op = true;
        }
      } else {
        clearopbeep(cap->oap);
      }
      break;
  
    // "zd": delete fold at cursor
    // "zD": delete fold at cursor recursively
    case 'd':
    case 'D':
      if (foldManualAllowed(false)) {
        if (VIsual_active) {
          nv_operator(cap);
        } else {
          deleteFold(curwin, curwin->w_cursor.lnum,
                     curwin->w_cursor.lnum, nchar == 'D', false);
        }
      }
      break;
  
    // "zE": erase all folds
    case 'E':
      if (foldmethodIsManual(curwin)) {
        clearFolding(curwin);
        changed_window_setting();
      } else if (foldmethodIsMarker(curwin)) {
        deleteFold(curwin, (linenr_T)1, curbuf->b_ml.ml_line_count, true, false);
      } else {
        emsg(_("E352: Cannot erase folds with current 'foldmethod'"));
      }
      break;
  
    // "zn": fold none: reset 'foldenable'
    case 'n':
      curwin->w_p_fen = false;
      break;
  
    // "zN": fold Normal: set 'foldenable'
    case 'N':
      curwin->w_p_fen = true;
      break;
  
    // "zi": invert folding: toggle 'foldenable'
    case 'i':
      curwin->w_p_fen = !curwin->w_p_fen;
      break;
  
    // "za": open closed fold or close open fold at cursor
    case 'a':
      if (hasFolding(curwin->w_cursor.lnum, NULL, NULL)) {
        openFold(curwin->w_cursor, cap->count1);
      } else {
        closeFold(curwin->w_cursor, cap->count1);
        curwin->w_p_fen = true;
      }
      break;
  
    // "zA": open fold at cursor recursively
    case 'A':
      if (hasFolding(curwin->w_cursor.lnum, NULL, NULL)) {
        openFoldRecurse(curwin->w_cursor);
      } else {
        closeFoldRecurse(curwin->w_cursor);
        curwin->w_p_fen = true;
      }
      break;
  
    // "zo": open fold at cursor or Visual area
    case 'o':
      if (VIsual_active) {
        nv_operator(cap);
      } else {
        openFold(curwin->w_cursor, cap->count1);
      }
      break;
  
    // "zO": open fold recursively
    case 'O':
      if (VIsual_active) {
        nv_operator(cap);
      } else {
        openFoldRecurse(curwin->w_cursor);
      }
      break;
  
    // "zc": close fold at cursor or Visual area
    case 'c':
      if (VIsual_active) {
        nv_operator(cap);
      } else {
        closeFold(curwin->w_cursor, cap->count1);
      }
      curwin->w_p_fen = true;
      break;
  
    // "zC": close fold recursively
    case 'C':
      if (VIsual_active) {
        nv_operator(cap);
      } else {
        closeFoldRecurse(curwin->w_cursor);
      }
      curwin->w_p_fen = true;
      break;
  
    // "zv": open folds at the cursor
    case 'v':
      foldOpenCursor();
      break;
  
    // "zx": re-apply 'foldlevel' and open folds at the cursor
    case 'x':
      curwin->w_p_fen = true;
      curwin->w_foldinvalid = true;               // recompute folds
      newFoldLevel();                             // update right now
      foldOpenCursor();
      break;
  
    // "zX": undo manual opens/closes, re-apply 'foldlevel'
    case 'X':
      curwin->w_p_fen = true;
      curwin->w_foldinvalid = true;               // recompute folds
      old_fdl = -1;                               // force an update
      break;
  
    // "zm": fold more
    case 'm':
      if (curwin->w_p_fdl > 0) {
        curwin->w_p_fdl -= cap->count1;
        if (curwin->w_p_fdl < 0) {
          curwin->w_p_fdl = 0;
        }
      }
      old_fdl = -1;                       // force an update
      curwin->w_p_fen = true;
      break;
  
    // "zM": close all folds
    case 'M':
      curwin->w_p_fdl = 0;
      old_fdl = -1;                       // force an update
      curwin->w_p_fen = true;
      break;
  
    // "zr": reduce folding
    case 'r':
      curwin->w_p_fdl += cap->count1;
      {
        int d = getDeepestNesting(curwin);
        if (curwin->w_p_fdl >= d) {
          curwin->w_p_fdl = d;
        }
      }
      break;
  
    case 'R':     //  "zR": open all folds
      curwin->w_p_fdl = getDeepestNesting(curwin);
      old_fdl = -1;                       // force an update
      break;
  
    case 'j':     // "zj" move to next fold downwards
    case 'k':     // "zk" move to next fold upwards
      if (foldMoveTo(true, nchar == 'j' ? FORWARD : BACKWARD,
                     cap->count1) == false) {
        clearopbeep(cap->oap);
      }
      break;
  
  
    case 'u':     // "zug" and "zuw": undo "zg" and "zw"
      no_mapping++;
      nchar = plain_vgetc();
      LANGMAP_ADJUST(nchar, true);
      no_mapping--;
      (void)add_to_showcmd(nchar);
      if (vim_strchr((char_u *)"gGwW", nchar) == NULL) {
        clearopbeep(cap->oap);
        break;
      }
      undo = true;
      FALLTHROUGH;
  
    case 'g':     // "zg": add good word to word list
    case 'w':     // "zw": add wrong word to word list
    case 'G':     // "zG": add good word to temp word list
    case 'W':     // "zW": add wrong word to temp word list
    {
      char_u *ptr = NULL;
      size_t len;
  
      if (checkclearop(cap->oap)) {
        break;
      }
      if (VIsual_active && !get_visual_text(cap, &ptr, &len)) {
        return;
      }
      if (ptr == NULL) {
        pos_T pos = curwin->w_cursor;
  
        // Find bad word under the cursor.  When 'spell' is
        // off this fails and find_ident_under_cursor() is
        // used below.
        emsg_off++;
        len = spell_move_to(curwin, FORWARD, true, true, NULL);
        emsg_off--;
        if (len != 0 && curwin->w_cursor.col <= pos.col) {
          ptr = ml_get_pos(&curwin->w_cursor);
        }
        curwin->w_cursor = pos;
      }
  
      if (ptr == NULL && (len = find_ident_under_cursor(&ptr, FIND_IDENT)) == 0) {
        return;
      }
      assert(len <= INT_MAX);
      spell_add_word(ptr, (int)len,
                     nchar == 'w' || nchar == 'W'
                     ? SPELL_ADD_BAD : SPELL_ADD_GOOD,
                     (nchar == 'G' || nchar == 'W') ? 0 : (int)cap->count1,
                     undo);
    }
    break;
  
    case '=':     // "z=": suggestions for a badly spelled word
      if (!checkclearop(cap->oap)) {
        spell_suggest((int)cap->count0);
      }
      break;
  
    default:
      clearopbeep(cap->oap);
    }
  
    // Redraw when 'foldenable' changed
    if (old_fen != curwin->w_p_fen) {
      if (foldmethodIsDiff(curwin) && curwin->w_p_scb) {
        // Adjust 'foldenable' in diff-synced windows.
        FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
          if (wp != curwin && foldmethodIsDiff(wp) && wp->w_p_scb) {
            wp->w_p_fen = curwin->w_p_fen;
            changed_window_setting_win(wp);
          }
        }
      }
      changed_window_setting();
    }
  
    // Redraw when 'foldlevel' changed.
    if (old_fdl != curwin->w_p_fdl) {
      newFoldLevel();
    }
  }
  
  
  /*
   * "Q" command.
   */
  static void nv_exmode(cmdarg_T *cap)
  {
    /*
     * Ignore 'Q' in Visual mode, just give a beep.
     */
    if (VIsual_active) {
      vim_beep(BO_EX);
    } else if (!checkclearop(cap->oap)) {
      do_exmode();
    }
  }
  
  /// Handle a ":" command and <Cmd>.
  static void nv_colon(cmdarg_T *cap)
  {
    int old_p_im;
    bool cmd_result;
    bool is_cmdkey = cap->cmdchar == K_COMMAND;
  
    if (VIsual_active && !is_cmdkey) {
      nv_operator(cap);
    } else {
      if (cap->oap->op_type != OP_NOP) {
        // Using ":" as a movement is charwise exclusive.
        cap->oap->motion_type = kMTCharWise;
        cap->oap->inclusive = false;
      } else if (cap->count0 && !is_cmdkey) {
        // translate "count:" into ":.,.+(count - 1)"
        stuffcharReadbuff('.');
        if (cap->count0 > 1) {
          stuffReadbuff(",.+");
          stuffnumReadbuff(cap->count0 - 1L);
        }
      }
  
      // When typing, don't type below an old message
      if (KeyTyped) {
        compute_cmdrow();
      }
  
      old_p_im = p_im;
  
      // get a command line and execute it
      cmd_result = do_cmdline(NULL, is_cmdkey ? getcmdkeycmd : getexline, NULL,
                              cap->oap->op_type != OP_NOP ? DOCMD_KEEPLINE : 0);
  
      // If 'insertmode' changed, enter or exit Insert mode
      if (p_im != old_p_im) {
        if (p_im) {
          restart_edit = 'i';
        } else {
          restart_edit = 0;
        }
      }
  
      if (cmd_result == false) {
        // The Ex command failed, do not execute the operator.
        clearop(cap->oap);
      } else if (cap->oap->op_type != OP_NOP
                 && (cap->oap->start.lnum > curbuf->b_ml.ml_line_count
                     || cap->oap->start.col >
                     (colnr_T)STRLEN(ml_get(cap->oap->start.lnum))
                     || did_emsg)) {
        // The start of the operator has become invalid by the Ex command.
        clearopbeep(cap->oap);
      }
    }
  }
  
  /*
   * Handle CTRL-G command.
   */
  static void nv_ctrlg(cmdarg_T *cap)
  {
    if (VIsual_active) {  // toggle Selection/Visual mode
      VIsual_select = !VIsual_select;
      trigger_modechanged();
      showmode();
    } else if (!checkclearop(cap->oap)) {
      // print full name if count given or :cd used
      fileinfo((int)cap->count0, false, true);
    }
  }
  
  /*
   * Handle CTRL-H <Backspace> command.
   */
  static void nv_ctrlh(cmdarg_T *cap)
  {
    if (VIsual_active && VIsual_select) {
      cap->cmdchar = 'x';         // BS key behaves like 'x' in Select mode
      v_visop(cap);
    } else {
      nv_left(cap);
    }
  }
  
  /*
   * CTRL-L: clear screen and redraw.
   */
  static void nv_clear(cmdarg_T *cap)
  {
    if (!checkclearop(cap->oap)) {
      // Clear all syntax states to force resyncing.
      syn_stack_free_all(curwin->w_s);
      FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
        wp->w_s->b_syn_slow = false;
      }
      redraw_later(curwin, CLEAR);
    }
  }
  
  /*
   * CTRL-O: In Select mode: switch to Visual mode for one command.
   * Otherwise: Go to older pcmark.
   */
  static void nv_ctrlo(cmdarg_T *cap)
  {
    if (VIsual_active && VIsual_select) {
      VIsual_select = false;
      trigger_modechanged();
      showmode();
      restart_VIsual_select = 2;          // restart Select mode later
    } else {
      cap->count1 = -cap->count1;
      nv_pcmark(cap);
    }
  }
  
  // CTRL-^ command, short for ":e #".  Works even when the alternate buffer is
  // not named.
  static void nv_hat(cmdarg_T *cap)
  {
    if (!checkclearopq(cap->oap)) {
      (void)buflist_getfile((int)cap->count0, (linenr_T)0,
                            GETF_SETMARK|GETF_ALT, false);
    }
  }
  
  /*
   * "Z" commands.
   */
  static void nv_Zet(cmdarg_T *cap)
  {
    if (!checkclearopq(cap->oap)) {
      switch (cap->nchar) {
      // "ZZ": equivalent to ":x".
      case 'Z':
        do_cmdline_cmd("x");
        break;
  
      // "ZQ": equivalent to ":q!" (Elvis compatible).
      case 'Q':
        do_cmdline_cmd("q!");
        break;
  
      default:
        clearopbeep(cap->oap);
      }
    }
  }
  
  /*
   * Call nv_ident() as if "c1" was used, with "c2" as next character.
   */
  void do_nv_ident(int c1, int c2)
  {
    oparg_T oa;
    cmdarg_T ca;
  
    clear_oparg(&oa);
    memset(&ca, 0, sizeof(ca));
    ca.oap = &oa;
    ca.cmdchar = c1;
    ca.nchar = c2;
    nv_ident(&ca);
  }
  
  /*
   * Handle the commands that use the word under the cursor.
   * [g] CTRL-]   :ta to current identifier
   * [g] 'K'      run program for current identifier
   * [g] '*'      / to current identifier or string
   * [g] '#'      ? to current identifier or string
   *  g  ']'      :tselect for current identifier
   */
  static void nv_ident(cmdarg_T *cap)
  {
    char_u *ptr = NULL;
    char_u *p;
    size_t n = 0;                 // init for GCC
    int cmdchar;
    bool g_cmd;                   // "g" command
    bool tag_cmd = false;
    char_u *aux_ptr;
  
    if (cap->cmdchar == 'g') {    // "g*", "g#", "g]" and "gCTRL-]"
      cmdchar = cap->nchar;
      g_cmd = true;
    } else {
      cmdchar = cap->cmdchar;
      g_cmd = false;
    }
  
    if (cmdchar == POUND) {       // the pound sign, '#' for English keyboards
      cmdchar = '#';
    }
  
    /*
     * The "]", "CTRL-]" and "K" commands accept an argument in Visual mode.
     */
    if (cmdchar == ']' || cmdchar == Ctrl_RSB || cmdchar == 'K') {
      if (VIsual_active && get_visual_text(cap, &ptr, &n) == false) {
        return;
      }
      if (checkclearopq(cap->oap)) {
        return;
      }
    }
  
    if (ptr == NULL && (n = find_ident_under_cursor(&ptr,
                                                    ((cmdchar == '*'
                                                      || cmdchar == '#')
                                                     ? FIND_IDENT|FIND_STRING
                                                     : FIND_IDENT))) == 0) {
      clearop(cap->oap);
      return;
    }
  
    // Allocate buffer to put the command in.  Inserting backslashes can
    // double the length of the word.  p_kp / curbuf->b_p_kp could be added
    // and some numbers.
    char_u *kp = *curbuf->b_p_kp == NUL ? p_kp : curbuf->b_p_kp;  // 'keywordprg'
    assert(*kp != NUL);  // option.c:do_set() should default to ":help" if empty.
    bool kp_ex = (*kp == ':');  // 'keywordprg' is an ex command
    bool kp_help = (STRCMP(kp, ":he") == 0 || STRCMP(kp, ":help") == 0);
    if (kp_help && *skipwhite(ptr) == NUL) {
      emsg(_(e_noident));   // found white space only
      return;
    }
    size_t buf_size = n * 2 + 30 + STRLEN(kp);
    char *buf = xmalloc(buf_size);
    buf[0] = NUL;
  
    switch (cmdchar) {
    case '*':
    case '#':
      /*
       * Put cursor at start of word, makes search skip the word
       * under the cursor.
       * Call setpcmark() first, so "*``" puts the cursor back where
       * it was.
       */
      setpcmark();
      curwin->w_cursor.col = (colnr_T)(ptr - get_cursor_line_ptr());
  
      if (!g_cmd && vim_iswordp(ptr)) {
        STRCPY(buf, "\\<");
      }
      no_smartcase = true;                // don't use 'smartcase' now
      break;
  
    case 'K':
      if (kp_help) {
        STRCPY(buf, "he! ");
      } else if (kp_ex) {
        if (cap->count0 != 0) {  // Send the count to the ex command.
          snprintf(buf, buf_size, "%" PRId64, (int64_t)(cap->count0));
        }
        STRCAT(buf, kp);
        STRCAT(buf, " ");
      } else {
        // An external command will probably use an argument starting
        // with "-" as an option.  To avoid trouble we skip the "-".
        while (*ptr == '-' && n > 0) {
          ++ptr;
          --n;
        }
        if (n == 0) {
          emsg(_(e_noident));              // found dashes only
          xfree(buf);
          return;
        }
  
        // When a count is given, turn it into a range.  Is this
        // really what we want?
        bool isman = (STRCMP(kp, "man") == 0);
        bool isman_s = (STRCMP(kp, "man -s") == 0);
        if (cap->count0 != 0 && !(isman || isman_s)) {
          snprintf(buf, buf_size, ".,.+%" PRId64, (int64_t)(cap->count0 - 1));
        }
  
        do_cmdline_cmd("tabnew");
        STRCAT(buf, "terminal ");
        if (cap->count0 == 0 && isman_s) {
          STRCAT(buf, "man");
        } else {
          STRCAT(buf, kp);
        }
        STRCAT(buf, " ");
        if (cap->count0 != 0 && (isman || isman_s)) {
          snprintf(buf + STRLEN(buf), buf_size - STRLEN(buf), "%" PRId64,
                   (int64_t)cap->count0);
          STRCAT(buf, " ");
        }
      }
      break;
  
    case ']':
      tag_cmd = true;
      if (p_cst) {
        STRCPY(buf, "cstag ");
      } else {
        STRCPY(buf, "ts ");
      }
      break;
  
    default:
      tag_cmd = true;
      if (curbuf->b_help) {
        STRCPY(buf, "he! ");
      } else {
        if (g_cmd) {
          STRCPY(buf, "tj ");
        } else {
          snprintf(buf, buf_size, "%" PRId64 "ta ", (int64_t)cap->count0);
        }
      }
    }
  
    // Now grab the chars in the identifier
    if (cmdchar == 'K' && !kp_help) {
      ptr = vim_strnsave(ptr, n);
      if (kp_ex) {
        // Escape the argument properly for an Ex command
        p = (char_u *)vim_strsave_fnameescape((const char *)ptr, false);
      } else {
        // Escape the argument properly for a shell command
        p = vim_strsave_shellescape(ptr, true, true);
      }
      xfree(ptr);
      char *newbuf = xrealloc(buf, STRLEN(buf) + STRLEN(p) + 1);
      buf = newbuf;
      STRCAT(buf, p);
      xfree(p);
    } else {
      if (cmdchar == '*') {
        aux_ptr = (char_u *)(p_magic ? "/.*~[^$\\" : "/^$\\");
      } else if (cmdchar == '#') {
        aux_ptr = (char_u *)(p_magic ? "/?.*~[^$\\" : "/?^$\\");
      } else if (tag_cmd) {
        if (curbuf->b_help) {
          // ":help" handles unescaped argument
          aux_ptr = (char_u *)"";
        } else {
          aux_ptr = (char_u *)"\\|\"\n[";
        }
      } else {
        aux_ptr = (char_u *)"\\|\"\n*?[";
      }
  
      p = (char_u *)buf + STRLEN(buf);
      while (n-- > 0) {
        // put a backslash before \ and some others
        if (vim_strchr(aux_ptr, *ptr) != NULL) {
          *p++ = '\\';
        }
        // When current byte is a part of multibyte character, copy all
        // bytes of that character.
        const size_t len = (size_t)(utfc_ptr2len(ptr) - 1);
        for (size_t i = 0; i < len && n > 0; i++, n--) {
          *p++ = *ptr++;
        }
        *p++ = *ptr++;
      }
      *p = NUL;
    }
  
    /*
     * Execute the command.
     */
    if (cmdchar == '*' || cmdchar == '#') {
      if (!g_cmd
          && vim_iswordp(mb_prevptr(get_cursor_line_ptr(), ptr))) {
        STRCAT(buf, "\\>");
      }
      // put pattern in search history
      init_history();
      add_to_history(HIST_SEARCH, (char_u *)buf, true, NUL);
      (void)normal_search(cap, cmdchar == '*' ? '/' : '?', (char_u *)buf, 0,
                          NULL);
    } else {
      g_tag_at_cursor = true;
      do_cmdline_cmd(buf);
      g_tag_at_cursor = false;
  
      if (cmdchar == 'K' && !kp_ex && !kp_help) {
        // Start insert mode in terminal buffer
        restart_edit = 'i';
  
        add_map((char_u *)"<buffer> <esc> <Cmd>call jobstop(&channel)<CR>", TERM_FOCUS, true);
        do_cmdline_cmd("autocmd TermClose <buffer> "
                       " if !v:event.status |"
                       "   exec 'bdelete! ' .. expand('<abuf>') |"
                       " endif");
      }
    }
  
    xfree(buf);
  }
  
  /// Get visually selected text, within one line only.
  ///
  /// @param pp    return: start of selected text
  /// @param lenp  return: length of selected text
  ///
  /// @return      false if more than one line selected.
  bool get_visual_text(cmdarg_T *cap, char_u **pp, size_t *lenp)
  {
    if (VIsual_mode != 'V') {
      unadjust_for_sel();
    }
    if (VIsual.lnum != curwin->w_cursor.lnum) {
      if (cap != NULL) {
        clearopbeep(cap->oap);
      }
      return false;
    }
    if (VIsual_mode == 'V') {
      *pp = get_cursor_line_ptr();
      *lenp = STRLEN(*pp);
    } else {
      if (lt(curwin->w_cursor, VIsual)) {
        *pp = ml_get_pos(&curwin->w_cursor);
        *lenp = (size_t)VIsual.col - (size_t)curwin->w_cursor.col + 1;
      } else {
        *pp = ml_get_pos(&VIsual);
        *lenp = (size_t)curwin->w_cursor.col - (size_t)VIsual.col + 1;
      }
      // Correct the length to include the whole last character.
      *lenp += (size_t)(utfc_ptr2len(*pp + (*lenp - 1)) - 1);
    }
    reset_VIsual_and_resel();
    return true;
  }
  
  /*
   * CTRL-T: backwards in tag stack
   */
  static void nv_tagpop(cmdarg_T *cap)
  {
    if (!checkclearopq(cap->oap)) {
      do_tag((char_u *)"", DT_POP, (int)cap->count1, false, true);
    }
  }
  
  /*
   * Handle scrolling command 'H', 'L' and 'M'.
   */
  static void nv_scroll(cmdarg_T *cap)
  {
    int used = 0;
    long n;
    linenr_T lnum;
    int half;
  
    cap->oap->motion_type = kMTLineWise;
    setpcmark();
  
    if (cap->cmdchar == 'L') {
      validate_botline(curwin);          // make sure curwin->w_botline is valid
      curwin->w_cursor.lnum = curwin->w_botline - 1;
      if (cap->count1 - 1 >= curwin->w_cursor.lnum) {
        curwin->w_cursor.lnum = 1;
      } else {
        if (hasAnyFolding(curwin)) {
          // Count a fold for one screen line.
          for (n = cap->count1 - 1; n > 0
               && curwin->w_cursor.lnum > curwin->w_topline; --n) {
            (void)hasFolding(curwin->w_cursor.lnum,
                             &curwin->w_cursor.lnum, NULL);
            --curwin->w_cursor.lnum;
          }
        } else {
          curwin->w_cursor.lnum -= cap->count1 - 1;
        }
      }
    } else {
      if (cap->cmdchar == 'M') {
        // Don't count filler lines above the window.
        used -= win_get_fill(curwin, curwin->w_topline)
                - curwin->w_topfill;
        validate_botline(curwin);  // make sure w_empty_rows is valid
        half = (curwin->w_height_inner - curwin->w_empty_rows + 1) / 2;
        for (n = 0; curwin->w_topline + n < curbuf->b_ml.ml_line_count; n++) {
          // Count half he number of filler lines to be "below this
          // line" and half to be "above the next line".
          if (n > 0 && used + win_get_fill(curwin, curwin->w_topline + n) / 2 >= half) {
            n--;
            break;
          }
          used += plines_win(curwin, curwin->w_topline + n, true);
          if (used >= half) {
            break;
          }
          if (hasFolding(curwin->w_topline + n, NULL, &lnum)) {
            n = lnum - curwin->w_topline;
          }
        }
        if (n > 0 && used > curwin->w_height_inner) {
          n--;
        }
      } else {  // (cap->cmdchar == 'H')
        n = cap->count1 - 1;
        if (hasAnyFolding(curwin)) {
          // Count a fold for one screen line.
          lnum = curwin->w_topline;
          while (n-- > 0 && lnum < curwin->w_botline - 1) {
            (void)hasFolding(lnum, NULL, &lnum);
            lnum++;
          }
          n = lnum - curwin->w_topline;
        }
      }
      curwin->w_cursor.lnum = curwin->w_topline + n;
      if (curwin->w_cursor.lnum > curbuf->b_ml.ml_line_count) {
        curwin->w_cursor.lnum = curbuf->b_ml.ml_line_count;
      }
    }
  
    // Correct for 'so', except when an operator is pending.
    if (cap->oap->op_type == OP_NOP) {
      cursor_correct();
    }
    beginline(BL_SOL | BL_FIX);
  }
  
  /*
   * Cursor right commands.
   */
  static void nv_right(cmdarg_T *cap)
  {
    long n;
    int PAST_LINE;
  
    if (mod_mask & (MOD_MASK_SHIFT | MOD_MASK_CTRL)) {
      // <C-Right> and <S-Right> move a word or WORD right
      if (mod_mask & MOD_MASK_CTRL) {
        cap->arg = true;
      }
      nv_wordcmd(cap);
      return;
    }
  
    cap->oap->motion_type = kMTCharWise;
    cap->oap->inclusive = false;
    PAST_LINE = (VIsual_active && *p_sel != 'o');
  
    /*
     * In virtual mode, there's no such thing as "PAST_LINE", as lines are
     * (theoretically) infinitely long.
     */
    if (virtual_active()) {
      PAST_LINE = 0;
    }
  
    for (n = cap->count1; n > 0; --n) {
      if ((!PAST_LINE && oneright() == false)
          || (PAST_LINE
              && *get_cursor_pos_ptr() == NUL)) {
        //          <Space> wraps to next line if 'whichwrap' has 's'.
        //              'l' wraps to next line if 'whichwrap' has 'l'.
        // CURS_RIGHT wraps to next line if 'whichwrap' has '>'.
        if (((cap->cmdchar == ' ' && vim_strchr(p_ww, 's') != NULL)
             || (cap->cmdchar == 'l' && vim_strchr(p_ww, 'l') != NULL)
             || (cap->cmdchar == K_RIGHT && vim_strchr(p_ww, '>') != NULL))
            && curwin->w_cursor.lnum < curbuf->b_ml.ml_line_count) {
          // When deleting we also count the NL as a character.
          // Set cap->oap->inclusive when last char in the line is
          // included, move to next line after that
          if (cap->oap->op_type != OP_NOP
              && !cap->oap->inclusive
              && !LINEEMPTY(curwin->w_cursor.lnum)) {
            cap->oap->inclusive = true;
          } else {
            ++curwin->w_cursor.lnum;
            curwin->w_cursor.col = 0;
            curwin->w_cursor.coladd = 0;
            curwin->w_set_curswant = true;
            cap->oap->inclusive = false;
          }
          continue;
        }
        if (cap->oap->op_type == OP_NOP) {
          // Only beep and flush if not moved at all
          if (n == cap->count1) {
            beep_flush();
          }
        } else {
          if (!LINEEMPTY(curwin->w_cursor.lnum)) {
            cap->oap->inclusive = true;
          }
        }
        break;
      } else if (PAST_LINE) {
        curwin->w_set_curswant = true;
        if (virtual_active()) {
          oneright();
        } else {
          curwin->w_cursor.col += utfc_ptr2len(get_cursor_pos_ptr());
        }
      }
    }
    if (n != cap->count1 && (fdo_flags & FDO_HOR) && KeyTyped
        && cap->oap->op_type == OP_NOP) {
      foldOpenCursor();
    }
  }
  
  /*
   * Cursor left commands.
   *
   * Returns true when operator end should not be adjusted.
   */
  static void nv_left(cmdarg_T *cap)
  {
    long n;
  
    if (mod_mask & (MOD_MASK_SHIFT | MOD_MASK_CTRL)) {
      // <C-Left> and <S-Left> move a word or WORD left
      if (mod_mask & MOD_MASK_CTRL) {
        cap->arg = 1;
      }
      nv_bck_word(cap);
      return;
    }
  
    cap->oap->motion_type = kMTCharWise;
    cap->oap->inclusive = false;
    for (n = cap->count1; n > 0; --n) {
      if (oneleft() == false) {
        // <BS> and <Del> wrap to previous line if 'whichwrap' has 'b'.
        //                 'h' wraps to previous line if 'whichwrap' has 'h'.
        //           CURS_LEFT wraps to previous line if 'whichwrap' has '<'.
        if ((((cap->cmdchar == K_BS || cap->cmdchar == Ctrl_H)
              && vim_strchr(p_ww, 'b') != NULL)
             || (cap->cmdchar == 'h' && vim_strchr(p_ww, 'h') != NULL)
             || (cap->cmdchar == K_LEFT && vim_strchr(p_ww, '<') != NULL))
            && curwin->w_cursor.lnum > 1) {
          curwin->w_cursor.lnum--;
          coladvance(MAXCOL);
          curwin->w_set_curswant = true;
  
          // When the NL before the first char has to be deleted we
          // put the cursor on the NUL after the previous line.
          // This is a very special case, be careful!
          // Don't adjust op_end now, otherwise it won't work.
          if ((cap->oap->op_type == OP_DELETE || cap->oap->op_type == OP_CHANGE)
              && !LINEEMPTY(curwin->w_cursor.lnum)) {
            char_u *cp = get_cursor_pos_ptr();
  
            if (*cp != NUL) {
              curwin->w_cursor.col += utfc_ptr2len(cp);
            }
            cap->retval |= CA_NO_ADJ_OP_END;
          }
          continue;
        }
        // Only beep and flush if not moved at all
        else if (cap->oap->op_type == OP_NOP && n == cap->count1) {
          beep_flush();
        }
        break;
      }
    }
    if (n != cap->count1 && (fdo_flags & FDO_HOR) && KeyTyped
        && cap->oap->op_type == OP_NOP) {
      foldOpenCursor();
    }
  }
  
  /*
   * Cursor up commands.
   * cap->arg is true for "-": Move cursor to first non-blank.
   */
  static void nv_up(cmdarg_T *cap)
  {
    if (mod_mask & MOD_MASK_SHIFT) {
      // <S-Up> is page up
      cap->arg = BACKWARD;
      nv_page(cap);
    } else {
      cap->oap->motion_type = kMTLineWise;
      if (cursor_up(cap->count1, cap->oap->op_type == OP_NOP) == false) {
        clearopbeep(cap->oap);
      } else if (cap->arg) {
        beginline(BL_WHITE | BL_FIX);
      }
    }
  }
  
  /*
   * Cursor down commands.
   * cap->arg is true for CR and "+": Move cursor to first non-blank.
   */
  static void nv_down(cmdarg_T *cap)
  {
    if (mod_mask & MOD_MASK_SHIFT) {
      // <S-Down> is page down
      cap->arg = FORWARD;
      nv_page(cap);
    } else if (bt_quickfix(curbuf) && cap->cmdchar == CAR) {
      // Quickfix window only: view the result under the cursor.
      qf_view_result(false);
    } else {
      // In the cmdline window a <CR> executes the command.
      if (cmdwin_type != 0 && cap->cmdchar == CAR) {
        cmdwin_result = CAR;
      } else if (bt_prompt(curbuf) && cap->cmdchar == CAR
                 && curwin->w_cursor.lnum == curbuf->b_ml.ml_line_count) {
        // In a prompt buffer a <CR> in the last line invokes the callback.
        invoke_prompt_callback();
        if (restart_edit == 0) {
          restart_edit = 'a';
        }
      } else {
        cap->oap->motion_type = kMTLineWise;
        if (cursor_down(cap->count1, cap->oap->op_type == OP_NOP) == false) {
          clearopbeep(cap->oap);
        } else if (cap->arg) {
          beginline(BL_WHITE | BL_FIX);
        }
      }
    }
  }
  
  /*
   * Grab the file name under the cursor and edit it.
   */
  static void nv_gotofile(cmdarg_T *cap)
  {
    char_u *ptr;
    linenr_T lnum = -1;
  
    if (text_locked()) {
      clearopbeep(cap->oap);
      text_locked_msg();
      return;
    }
    if (curbuf_locked()) {
      clearop(cap->oap);
      return;
    }
  
    ptr = grab_file_name(cap->count1, &lnum);
  
    if (ptr != NULL) {
      // do autowrite if necessary
      if (curbufIsChanged() && curbuf->b_nwindows <= 1 && !buf_hide(curbuf)) {
        (void)autowrite(curbuf, false);
      }
      setpcmark();
      if (do_ecmd(0, ptr, NULL, NULL, ECMD_LAST,
                  buf_hide(curbuf) ? ECMD_HIDE : 0, curwin) == OK
          && cap->nchar == 'F' && lnum >= 0) {
        curwin->w_cursor.lnum = lnum;
        check_cursor_lnum();
        beginline(BL_SOL | BL_FIX);
      }
      xfree(ptr);
    } else {
      clearop(cap->oap);
    }
  }
  
  /*
   * <End> command: to end of current line or last line.
   */
  static void nv_end(cmdarg_T *cap)
  {
    if (cap->arg || (mod_mask & MOD_MASK_CTRL)) {  // CTRL-END = goto last line
      cap->arg = true;
      nv_goto(cap);
      cap->count1 = 1;                    // to end of current line
    }
    nv_dollar(cap);
  }
  
  /*
   * Handle the "$" command.
   */
  static void nv_dollar(cmdarg_T *cap)
  {
    cap->oap->motion_type = kMTCharWise;
    cap->oap->inclusive = true;
    // In virtual mode when off the edge of a line and an operator
    // is pending (whew!) keep the cursor where it is.
    // Otherwise, send it to the end of the line.
    if (!virtual_active() || gchar_cursor() != NUL
        || cap->oap->op_type == OP_NOP) {
      curwin->w_curswant = MAXCOL;        // so we stay at the end
    }
    if (cursor_down(cap->count1 - 1,
                    cap->oap->op_type == OP_NOP) == false) {
      clearopbeep(cap->oap);
    } else if ((fdo_flags & FDO_HOR) && KeyTyped && cap->oap->op_type == OP_NOP) {
      foldOpenCursor();
    }
  }
  
  /*
   * Implementation of '?' and '/' commands.
   * If cap->arg is true don't set PC mark.
   */
  static void nv_search(cmdarg_T *cap)
  {
    oparg_T *oap = cap->oap;
    pos_T save_cursor = curwin->w_cursor;
  
    if (cap->cmdchar == '?' && cap->oap->op_type == OP_ROT13) {
      // Translate "g??" to "g?g?"
      cap->cmdchar = 'g';
      cap->nchar = '?';
      nv_operator(cap);
      return;
    }
  
    // When using 'incsearch' the cursor may be moved to set a different search
    // start position.
    cap->searchbuf = getcmdline(cap->cmdchar, cap->count1, 0, true);
  
    if (cap->searchbuf == NULL) {
      clearop(oap);
      return;
    }
  
    (void)normal_search(cap, cap->cmdchar, cap->searchbuf,
                        (cap->arg || !equalpos(save_cursor, curwin->w_cursor))
                        ? 0 : SEARCH_MARK, NULL);
  }
  
  /*
   * Handle "N" and "n" commands.
   * cap->arg is SEARCH_REV for "N", 0 for "n".
   */
  static void nv_next(cmdarg_T *cap)
  {
    pos_T old = curwin->w_cursor;
    int wrapped = false;
    int i = normal_search(cap, 0, NULL, SEARCH_MARK | cap->arg, &wrapped);
  
    if (i == 1 && !wrapped && equalpos(old, curwin->w_cursor)) {
      // Avoid getting stuck on the current cursor position, which can happen when
      // an offset is given and the cursor is on the last char in the buffer:
      // Repeat with count + 1.
      cap->count1 += 1;
      (void)normal_search(cap, 0, NULL, SEARCH_MARK | cap->arg, NULL);
      cap->count1 -= 1;
    }
  }
  
  /// Search for "pat" in direction "dir" ('/' or '?', 0 for repeat).
  /// Uses only cap->count1 and cap->oap from "cap".
  ///
  /// @param opt  extra flags for do_search()
  ///
  /// @return 0 for failure, 1 for found, 2 for found and line offset added.
  static int normal_search(cmdarg_T *cap, int dir, char_u *pat, int opt, int *wrapped)
  {
    int i;
    searchit_arg_T sia;
  
    cap->oap->motion_type = kMTCharWise;
    cap->oap->inclusive = false;
    cap->oap->use_reg_one = true;
    curwin->w_set_curswant = true;
  
    memset(&sia, 0, sizeof(sia));
    i = do_search(cap->oap, dir, dir, pat, cap->count1,
                  opt | SEARCH_OPT | SEARCH_ECHO | SEARCH_MSG, &sia);
    if (wrapped != NULL) {
      *wrapped = sia.sa_wrapped;
    }
    if (i == 0) {
      clearop(cap->oap);
    } else {
      if (i == 2) {
        cap->oap->motion_type = kMTLineWise;
      }
      curwin->w_cursor.coladd = 0;
      if (cap->oap->op_type == OP_NOP && (fdo_flags & FDO_SEARCH) && KeyTyped) {
        foldOpenCursor();
      }
    }
  
    // "/$" will put the cursor after the end of the line, may need to
    // correct that here
    check_cursor();
    return i;
  }
  
  /*
   * Character search commands.
   * cap->arg is BACKWARD for 'F' and 'T', FORWARD for 'f' and 't', true for
   * ',' and false for ';'.
   * cap->nchar is NUL for ',' and ';' (repeat the search)
   */
  static void nv_csearch(cmdarg_T *cap)
  {
    bool t_cmd;
  
    if (cap->cmdchar == 't' || cap->cmdchar == 'T') {
      t_cmd = true;
    } else {
      t_cmd = false;
    }
  
    cap->oap->motion_type = kMTCharWise;
    if (IS_SPECIAL(cap->nchar) || searchc(cap, t_cmd) == false) {
      clearopbeep(cap->oap);
    } else {
      curwin->w_set_curswant = true;
      // Include a Tab for "tx" and for "dfx".
      if (gchar_cursor() == TAB && virtual_active() && cap->arg == FORWARD
          && (t_cmd || cap->oap->op_type != OP_NOP)) {
        colnr_T scol, ecol;
  
        getvcol(curwin, &curwin->w_cursor, &scol, NULL, &ecol);
        curwin->w_cursor.coladd = ecol - scol;
      } else {
        curwin->w_cursor.coladd = 0;
      }
      adjust_for_sel(cap);
      if ((fdo_flags & FDO_HOR) && KeyTyped && cap->oap->op_type == OP_NOP) {
        foldOpenCursor();
      }
    }
  }
  
  /*
   * "[" and "]" commands.
   * cap->arg is BACKWARD for "[" and FORWARD for "]".
   */
  static void nv_brackets(cmdarg_T *cap)
  {
    pos_T new_pos = { 0, 0, 0 };
    pos_T prev_pos;
    pos_T *pos = NULL;          // init for GCC
    pos_T old_pos;                    // cursor position before command
    int flag;
    long n;
    int findc;
    int c;
  
    cap->oap->motion_type = kMTCharWise;
    cap->oap->inclusive = false;
    old_pos = curwin->w_cursor;
    curwin->w_cursor.coladd = 0;              // TODO: don't do this for an error.
  
    /*
     * "[f" or "]f" : Edit file under the cursor (same as "gf")
     */
    if (cap->nchar == 'f') {
      nv_gotofile(cap);
    } else
    /*
     * Find the occurrence(s) of the identifier or define under cursor
     * in current and included files or jump to the first occurrence.
     *
     *                    search       list           jump
     *                  fwd   bwd    fwd   bwd     fwd    bwd
     * identifier     "]i"  "[i"   "]I"  "[I"     "]^I"  "[^I"
     * define           "]d"  "[d"   "]D"  "[D"   "]^D"  "[^D"
     */
    if (vim_strchr((char_u *)
                   "iI\011dD\004",
                   cap->nchar) != NULL) {
      char_u *ptr;
      size_t len;
  
      if ((len = find_ident_under_cursor(&ptr, FIND_IDENT)) == 0) {
        clearop(cap->oap);
      } else {
        find_pattern_in_path(ptr, 0, len, true,
                             cap->count0 == 0 ? !isupper(cap->nchar) : false,
                             (((cap->nchar & 0xf) == ('d' & 0xf))
                              ? FIND_DEFINE
                              : FIND_ANY),
                             cap->count1,
                             (isupper(cap->nchar) ? ACTION_SHOW_ALL :
                              islower(cap->nchar) ? ACTION_SHOW :
                              ACTION_GOTO),
                             (cap->cmdchar == ']'
                              ? curwin->w_cursor.lnum + 1
                              : (linenr_T)1),
                             MAXLNUM);
        curwin->w_set_curswant = true;
      }
    } else
    /*
     * "[{", "[(", "]}" or "])": go to Nth unclosed '{', '(', '}' or ')'
     * "[#", "]#": go to start/end of Nth innermost #if..#endif construct.
     * "[/", "[*", "]/", "]*": go to Nth comment start/end.
     * "[m" or "]m" search for prev/next start of (Java) method.
     * "[M" or "]M" search for prev/next end of (Java) method.
     */
    if ((cap->cmdchar == '['
         && vim_strchr((char_u *)"{(*/#mM", cap->nchar) != NULL)
        || (cap->cmdchar == ']'
            && vim_strchr((char_u *)"})*/#mM", cap->nchar) != NULL)) {
      if (cap->nchar == '*') {
        cap->nchar = '/';
      }
      prev_pos.lnum = 0;
      if (cap->nchar == 'm' || cap->nchar == 'M') {
        if (cap->cmdchar == '[') {
          findc = '{';
        } else {
          findc = '}';
        }
        n = 9999;
      } else {
        findc = cap->nchar;
        n = cap->count1;
      }
      for (; n > 0; --n) {
        if ((pos = findmatchlimit(cap->oap, findc,
                                  (cap->cmdchar == '[') ? FM_BACKWARD : FM_FORWARD, 0)) == NULL) {
          if (new_pos.lnum == 0) {        // nothing found
            if (cap->nchar != 'm' && cap->nchar != 'M') {
              clearopbeep(cap->oap);
            }
          } else {
            pos = &new_pos;               // use last one found
          }
          break;
        }
        prev_pos = new_pos;
        curwin->w_cursor = *pos;
        new_pos = *pos;
      }
      curwin->w_cursor = old_pos;
  
      /*
       * Handle "[m", "]m", "[M" and "[M".  The findmatchlimit() only
       * brought us to the match for "[m" and "]M" when inside a method.
       * Try finding the '{' or '}' we want to be at.
       * Also repeat for the given count.
       */
      if (cap->nchar == 'm' || cap->nchar == 'M') {
        // norm is true for "]M" and "[m"
        int norm = ((findc == '{') == (cap->nchar == 'm'));
  
        n = cap->count1;
        // found a match: we were inside a method
        if (prev_pos.lnum != 0) {
          pos = &prev_pos;
          curwin->w_cursor = prev_pos;
          if (norm) {
            --n;
          }
        } else {
          pos = NULL;
        }
        while (n > 0) {
          for (;;) {
            if ((findc == '{' ? dec_cursor() : inc_cursor()) < 0) {
              // if not found anything, that's an error
              if (pos == NULL) {
                clearopbeep(cap->oap);
              }
              n = 0;
              break;
            }
            c = gchar_cursor();
            if (c == '{' || c == '}') {
              // Must have found end/start of class: use it.
              // Or found the place to be at.
              if ((c == findc && norm) || (n == 1 && !norm)) {
                new_pos = curwin->w_cursor;
                pos = &new_pos;
                n = 0;
              } else if (new_pos.lnum == 0) {
                // if no match found at all, we started outside of the
                // class and we're inside now.  Just go on.
                new_pos = curwin->w_cursor;
                pos = &new_pos;
              }
              // found start/end of other method: go to match
              else if ((pos = findmatchlimit(cap->oap, findc,
                                             (cap->cmdchar == '[') ? FM_BACKWARD : FM_FORWARD,
                                             0)) == NULL) {
                n = 0;
              } else {
                curwin->w_cursor = *pos;
              }
              break;
            }
          }
          --n;
        }
        curwin->w_cursor = old_pos;
        if (pos == NULL && new_pos.lnum != 0) {
          clearopbeep(cap->oap);
        }
      }
      if (pos != NULL) {
        setpcmark();
        curwin->w_cursor = *pos;
        curwin->w_set_curswant = true;
        if ((fdo_flags & FDO_BLOCK) && KeyTyped
            && cap->oap->op_type == OP_NOP) {
          foldOpenCursor();
        }
      }
    }
    /*
     * "[[", "[]", "]]" and "][": move to start or end of function
     */
    else if (cap->nchar == '[' || cap->nchar == ']') {
      if (cap->nchar == cap->cmdchar) {               // "]]" or "[["
        flag = '{';
      } else {
        flag = '}';                   // "][" or "[]"
      }
      curwin->w_set_curswant = true;
      /*
       * Imitate strange Vi behaviour: When using "]]" with an operator
       * we also stop at '}'.
       */
      if (!findpar(&cap->oap->inclusive, cap->arg, cap->count1, flag,
                   (cap->oap->op_type != OP_NOP
                    && cap->arg == FORWARD && flag == '{'))) {
        clearopbeep(cap->oap);
      } else {
        if (cap->oap->op_type == OP_NOP) {
          beginline(BL_WHITE | BL_FIX);
        }
        if ((fdo_flags & FDO_BLOCK) && KeyTyped && cap->oap->op_type == OP_NOP) {
          foldOpenCursor();
        }
      }
    } else if (cap->nchar == 'p' || cap->nchar == 'P') {
      // "[p", "[P", "]P" and "]p": put with indent adjustment
      nv_put_opt(cap, true);
    }
    /*
     * "['", "[`", "]'" and "]`": jump to next mark
     */
    else if (cap->nchar == '\'' || cap->nchar == '`') {
      pos = &curwin->w_cursor;
      for (n = cap->count1; n > 0; --n) {
        prev_pos = *pos;
        pos = getnextmark(pos, cap->cmdchar == '[' ? BACKWARD : FORWARD,
                          cap->nchar == '\'');
        if (pos == NULL) {
          break;
        }
      }
      if (pos == NULL) {
        pos = &prev_pos;
      }
      nv_cursormark(cap, cap->nchar == '\'', pos);
    }
    /*
     * [ or ] followed by a middle mouse click: put selected text with
     * indent adjustment.  Any other button just does as usual.
     */
    else if (cap->nchar >= K_RIGHTRELEASE && cap->nchar <= K_LEFTMOUSE) {
      (void)do_mouse(cap->oap, cap->nchar,
                     (cap->cmdchar == ']') ? FORWARD : BACKWARD,
                     cap->count1, PUT_FIXINDENT);
    }
    /*
     * "[z" and "]z": move to start or end of open fold.
     */
    else if (cap->nchar == 'z') {
      if (foldMoveTo(false, cap->cmdchar == ']' ? FORWARD : BACKWARD,
                     cap->count1) == false) {
        clearopbeep(cap->oap);
      }
    }
    /*
     * "[c" and "]c": move to next or previous diff-change.
     */
    else if (cap->nchar == 'c') {
      if (diff_move_to(cap->cmdchar == ']' ? FORWARD : BACKWARD,
                       cap->count1) == false) {
        clearopbeep(cap->oap);
      }
    }
    /*
     * "[s", "[S", "]s" and "]S": move to next spell error.
     */
    else if (cap->nchar == 's' || cap->nchar == 'S') {
      setpcmark();
      for (n = 0; n < cap->count1; ++n) {
        if (spell_move_to(curwin, cap->cmdchar == ']' ? FORWARD : BACKWARD,
                          cap->nchar == 's', false, NULL) == 0) {
          clearopbeep(cap->oap);
          break;
        } else {
          curwin->w_set_curswant = true;
        }
      }
      if (cap->oap->op_type == OP_NOP && (fdo_flags & FDO_SEARCH) && KeyTyped) {
        foldOpenCursor();
      }
    }
    // Not a valid cap->nchar.
    else {
      clearopbeep(cap->oap);
    }
  }
  
  /*
   * Handle Normal mode "%" command.
   */
  static void nv_percent(cmdarg_T *cap)
  {
    pos_T *pos;
    linenr_T lnum = curwin->w_cursor.lnum;
  
    cap->oap->inclusive = true;
    if (cap->count0) {  // {cnt}% : goto {cnt} percentage in file
      if (cap->count0 > 100) {
        clearopbeep(cap->oap);
      } else {
        cap->oap->motion_type = kMTLineWise;
        setpcmark();
        // Round up, so 'normal 100%' always jumps at the line line.
        // Beyond 21474836 lines, (ml_line_count * 100 + 99) would
        // overflow on 32-bits, so use a formula with less accuracy
        // to avoid overflows.
        if (curbuf->b_ml.ml_line_count >= 21474836) {
          curwin->w_cursor.lnum = (curbuf->b_ml.ml_line_count + 99L)
                                  / 100L * cap->count0;
        } else {
          curwin->w_cursor.lnum = (curbuf->b_ml.ml_line_count *
                                   cap->count0 + 99L) / 100L;
        }
        if (curwin->w_cursor.lnum < 1) {
          curwin->w_cursor.lnum = 1;
        }
        if (curwin->w_cursor.lnum > curbuf->b_ml.ml_line_count) {
          curwin->w_cursor.lnum = curbuf->b_ml.ml_line_count;
        }
        beginline(BL_SOL | BL_FIX);
      }
    } else {  // "%" : go to matching paren
      cap->oap->motion_type = kMTCharWise;
      cap->oap->use_reg_one = true;
      if ((pos = findmatch(cap->oap, NUL)) == NULL) {
        clearopbeep(cap->oap);
      } else {
        setpcmark();
        curwin->w_cursor = *pos;
        curwin->w_set_curswant = true;
        curwin->w_cursor.coladd = 0;
        adjust_for_sel(cap);
      }
    }
    if (cap->oap->op_type == OP_NOP
        && lnum != curwin->w_cursor.lnum
        && (fdo_flags & FDO_PERCENT)
        && KeyTyped) {
      foldOpenCursor();
    }
  }
  
  /*
   * Handle "(" and ")" commands.
   * cap->arg is BACKWARD for "(" and FORWARD for ")".
   */
  static void nv_brace(cmdarg_T *cap)
  {
    cap->oap->motion_type = kMTCharWise;
    cap->oap->use_reg_one = true;
    // The motion used to be inclusive for "(", but that is not what Vi does.
    cap->oap->inclusive = false;
    curwin->w_set_curswant = true;
  
    if (findsent(cap->arg, cap->count1) == false) {
      clearopbeep(cap->oap);
    } else {
      // Don't leave the cursor on the NUL past end of line.
      adjust_cursor(cap->oap);
      curwin->w_cursor.coladd = 0;
      if ((fdo_flags & FDO_BLOCK) && KeyTyped && cap->oap->op_type == OP_NOP) {
        foldOpenCursor();
      }
    }
  }
  
  /*
   * "m" command: Mark a position.
   */
  static void nv_mark(cmdarg_T *cap)
  {
    if (!checkclearop(cap->oap)) {
      if (setmark(cap->nchar) == false) {
        clearopbeep(cap->oap);
      }
    }
  }
  
  /*
   * "{" and "}" commands.
   * cmd->arg is BACKWARD for "{" and FORWARD for "}".
   */
  static void nv_findpar(cmdarg_T *cap)
  {
    cap->oap->motion_type = kMTCharWise;
    cap->oap->inclusive = false;
    cap->oap->use_reg_one = true;
    curwin->w_set_curswant = true;
    if (!findpar(&cap->oap->inclusive, cap->arg, cap->count1, NUL, false)) {
      clearopbeep(cap->oap);
    } else {
      curwin->w_cursor.coladd = 0;
      if ((fdo_flags & FDO_BLOCK) && KeyTyped && cap->oap->op_type == OP_NOP) {
        foldOpenCursor();
      }
    }
  }
  
  /*
   * "u" command: Undo or make lower case.
   */
  static void nv_undo(cmdarg_T *cap)
  {
    if (cap->oap->op_type == OP_LOWER
        || VIsual_active) {
      // translate "<Visual>u" to "<Visual>gu" and "guu" to "gugu"
      cap->cmdchar = 'g';
      cap->nchar = 'u';
      nv_operator(cap);
    } else {
      nv_kundo(cap);
    }
  }
  
  /*
   * <Undo> command.
   */
  static void nv_kundo(cmdarg_T *cap)
  {
    if (!checkclearopq(cap->oap)) {
      if (bt_prompt(curbuf)) {
        clearopbeep(cap->oap);
        return;
      }
      u_undo((int)cap->count1);
      curwin->w_set_curswant = true;
    }
  }
  
  /*
   * Handle the "r" command.
   */
  static void nv_replace(cmdarg_T *cap)
  {
    char_u *ptr;
    int had_ctrl_v;
  
    if (checkclearop(cap->oap)) {
      return;
    }
    if (bt_prompt(curbuf) && !prompt_curpos_editable()) {
      clearopbeep(cap->oap);
      return;
    }
  
    // get another character
    if (cap->nchar == Ctrl_V) {
      had_ctrl_v = Ctrl_V;
      cap->nchar = get_literal();
      // Don't redo a multibyte character with CTRL-V.
      if (cap->nchar > DEL) {
        had_ctrl_v = NUL;
      }
    } else {
      had_ctrl_v = NUL;
    }
  
    // Abort if the character is a special key.
    if (IS_SPECIAL(cap->nchar)) {
      clearopbeep(cap->oap);
      return;
    }
  
    // Visual mode "r"
    if (VIsual_active) {
      if (got_int) {
        reset_VIsual();
      }
      if (had_ctrl_v) {
        // Use a special (negative) number to make a difference between a
        // literal CR or NL and a line break.
        if (cap->nchar == CAR) {
          cap->nchar = REPLACE_CR_NCHAR;
        } else if (cap->nchar == NL) {
          cap->nchar = REPLACE_NL_NCHAR;
        }
      }
      nv_operator(cap);
      return;
    }
  
    // Break tabs, etc.
    if (virtual_active()) {
      if (u_save_cursor() == false) {
        return;
      }
      if (gchar_cursor() == NUL) {
        // Add extra space and put the cursor on the first one.
        coladvance_force((colnr_T)(getviscol() + cap->count1));
        assert(cap->count1 <= INT_MAX);
        curwin->w_cursor.col -= (colnr_T)cap->count1;
      } else if (gchar_cursor() == TAB) {
        coladvance_force(getviscol());
      }
    }
  
    // Abort if not enough characters to replace.
    ptr = get_cursor_pos_ptr();
    if (STRLEN(ptr) < (unsigned)cap->count1
        || (mb_charlen(ptr) < cap->count1)) {
      clearopbeep(cap->oap);
      return;
    }
  
    // Replacing with a TAB is done by edit() when it is complicated because
    // 'expandtab' or 'smarttab' is set.  CTRL-V TAB inserts a literal TAB.
    // Other characters are done below to avoid problems with things like
    // CTRL-V 048 (for edit() this would be R CTRL-V 0 ESC).
    if (had_ctrl_v != Ctrl_V && cap->nchar == '\t' && (curbuf->b_p_et || p_sta)) {
      stuffnumReadbuff(cap->count1);
      stuffcharReadbuff('R');
      stuffcharReadbuff('\t');
      stuffcharReadbuff(ESC);
      return;
    }
  
    // save line for undo
    if (u_save_cursor() == false) {
      return;
    }
  
    if (had_ctrl_v != Ctrl_V && (cap->nchar == '\r' || cap->nchar == '\n')) {
      /*
       * Replace character(s) by a single newline.
       * Strange vi behaviour: Only one newline is inserted.
       * Delete the characters here.
       * Insert the newline with an insert command, takes care of
       * autoindent.      The insert command depends on being on the last
       * character of a line or not.
       */
      (void)del_chars(cap->count1, false);        // delete the characters
      stuffcharReadbuff('\r');
      stuffcharReadbuff(ESC);
  
      // Give 'r' to edit(), to get the redo command right.
      invoke_edit(cap, true, 'r', false);
    } else {
      prep_redo(cap->oap->regname, cap->count1,
                NUL, 'r', NUL, had_ctrl_v, cap->nchar);
  
      curbuf->b_op_start = curwin->w_cursor;
      const int old_State = State;
  
      if (cap->ncharC1 != 0) {
        AppendCharToRedobuff(cap->ncharC1);
      }
      if (cap->ncharC2 != 0) {
        AppendCharToRedobuff(cap->ncharC2);
      }
  
      // This is slow, but it handles replacing a single-byte with a
      // multi-byte and the other way around.  Also handles adding
      // composing characters for utf-8.
      for (long n = cap->count1; n > 0; n--) {
        State = REPLACE;
        if (cap->nchar == Ctrl_E || cap->nchar == Ctrl_Y) {
          int c = ins_copychar(curwin->w_cursor.lnum
                               + (cap->nchar == Ctrl_Y ? -1 : 1));
          if (c != NUL) {
            ins_char(c);
          } else {
            // will be decremented further down
            curwin->w_cursor.col++;
          }
        } else {
          ins_char(cap->nchar);
        }
        State = old_State;
        if (cap->ncharC1 != 0) {
          ins_char(cap->ncharC1);
        }
        if (cap->ncharC2 != 0) {
          ins_char(cap->ncharC2);
        }
      }
      curwin->w_cursor.col--;         // cursor on the last replaced char
      // if the character on the left of the current cursor is a multi-byte
      // character, move two characters left
      mb_adjust_cursor();
      curbuf->b_op_end = curwin->w_cursor;
      curwin->w_set_curswant = true;
      set_last_insert(cap->nchar);
    }
  
    foldUpdateAfterInsert();
  }
  
  /*
   * 'o': Exchange start and end of Visual area.
   * 'O': same, but in block mode exchange left and right corners.
   */
  static void v_swap_corners(int cmdchar)
  {
    pos_T old_cursor;
    colnr_T left, right;
  
    if (cmdchar == 'O' && VIsual_mode == Ctrl_V) {
      old_cursor = curwin->w_cursor;
      getvcols(curwin, &old_cursor, &VIsual, &left, &right);
      curwin->w_cursor.lnum = VIsual.lnum;
      coladvance(left);
      VIsual = curwin->w_cursor;
  
      curwin->w_cursor.lnum = old_cursor.lnum;
      curwin->w_curswant = right;
      // 'selection "exclusive" and cursor at right-bottom corner: move it
      // right one column
      if (old_cursor.lnum >= VIsual.lnum && *p_sel == 'e') {
        ++curwin->w_curswant;
      }
      coladvance(curwin->w_curswant);
      if (curwin->w_cursor.col == old_cursor.col
          && (!virtual_active()
              || curwin->w_cursor.coladd ==
              old_cursor.coladd)) {
        curwin->w_cursor.lnum = VIsual.lnum;
        if (old_cursor.lnum <= VIsual.lnum && *p_sel == 'e') {
          ++right;
        }
        coladvance(right);
        VIsual = curwin->w_cursor;
  
        curwin->w_cursor.lnum = old_cursor.lnum;
        coladvance(left);
        curwin->w_curswant = left;
      }
    } else {
      old_cursor = curwin->w_cursor;
      curwin->w_cursor = VIsual;
      VIsual = old_cursor;
      curwin->w_set_curswant = true;
    }
  }
  
  /*
   * "R" (cap->arg is false) and "gR" (cap->arg is true).
   */
  static void nv_Replace(cmdarg_T *cap)
  {
    if (VIsual_active) {          // "R" is replace lines
      cap->cmdchar = 'c';
      cap->nchar = NUL;
      VIsual_mode_orig = VIsual_mode;     // remember original area for gv
      VIsual_mode = 'V';
      nv_operator(cap);
    } else if (!checkclearopq(cap->oap)) {
      if (!MODIFIABLE(curbuf)) {
        emsg(_(e_modifiable));
      } else {
        if (virtual_active()) {
          coladvance(getviscol());
        }
        invoke_edit(cap, false, cap->arg ? 'V' : 'R', false);
      }
    }
  }
  
  /*
   * "gr".
   */
  static void nv_vreplace(cmdarg_T *cap)
  {
    if (VIsual_active) {
      cap->cmdchar = 'r';
      cap->nchar = cap->extra_char;
      nv_replace(cap);            // Do same as "r" in Visual mode for now
    } else if (!checkclearopq(cap->oap)) {
      if (!MODIFIABLE(curbuf)) {
        emsg(_(e_modifiable));
      } else {
        if (cap->extra_char == Ctrl_V) {          // get another character
          cap->extra_char = get_literal();
        }
        stuffcharReadbuff(cap->extra_char);
        stuffcharReadbuff(ESC);
        if (virtual_active()) {
          coladvance(getviscol());
        }
        invoke_edit(cap, true, 'v', false);
      }
    }
  }
  
  /*
   * Swap case for "~" command, when it does not work like an operator.
   */
  static void n_swapchar(cmdarg_T *cap)
  {
    long n;
    pos_T startpos;
    int did_change = 0;
  
    if (checkclearopq(cap->oap)) {
      return;
    }
  
    if (LINEEMPTY(curwin->w_cursor.lnum) && vim_strchr(p_ww, '~') == NULL) {
      clearopbeep(cap->oap);
      return;
    }
  
    prep_redo_cmd(cap);
  
    if (u_save_cursor() == false) {
      return;
    }
  
    startpos = curwin->w_cursor;
    for (n = cap->count1; n > 0; --n) {
      did_change |= swapchar(cap->oap->op_type, &curwin->w_cursor);
      inc_cursor();
      if (gchar_cursor() == NUL) {
        if (vim_strchr(p_ww, '~') != NULL
            && curwin->w_cursor.lnum < curbuf->b_ml.ml_line_count) {
          ++curwin->w_cursor.lnum;
          curwin->w_cursor.col = 0;
          if (n > 1) {
            if (u_savesub(curwin->w_cursor.lnum) == false) {
              break;
            }
            u_clearline();
          }
        } else {
          break;
        }
      }
    }
  
  
    check_cursor();
    curwin->w_set_curswant = true;
    if (did_change) {
      changed_lines(startpos.lnum, startpos.col, curwin->w_cursor.lnum + 1,
                    0L, true);
      curbuf->b_op_start = startpos;
      curbuf->b_op_end = curwin->w_cursor;
      if (curbuf->b_op_end.col > 0) {
        --curbuf->b_op_end.col;
      }
    }
  }
  
  /*
   * Move cursor to mark.
   */
  static void nv_cursormark(cmdarg_T *cap, int flag, pos_T *pos)
  {
    if (check_mark(pos) == false) {
      clearop(cap->oap);
    } else {
      if (cap->cmdchar == '\''
          || cap->cmdchar == '`'
          || cap->cmdchar == '['
          || cap->cmdchar == ']') {
        setpcmark();
      }
      curwin->w_cursor = *pos;
      if (flag) {
        beginline(BL_WHITE | BL_FIX);
      } else {
        check_cursor();
      }
    }
    cap->oap->motion_type = flag ? kMTLineWise : kMTCharWise;
    if (cap->cmdchar == '`') {
      cap->oap->use_reg_one = true;
    }
    cap->oap->inclusive = false;  // ignored if not kMTCharWise
    curwin->w_set_curswant = true;
  }
  
  /*
   * Handle commands that are operators in Visual mode.
   */
  static void v_visop(cmdarg_T *cap)
  {
    static char_u trans[] = "YyDdCcxdXdAAIIrr";
  
    // Uppercase means linewise, except in block mode, then "D" deletes till
    // the end of the line, and "C" replaces till EOL
    if (isupper(cap->cmdchar)) {
      if (VIsual_mode != Ctrl_V) {
        VIsual_mode_orig = VIsual_mode;
        VIsual_mode = 'V';
      } else if (cap->cmdchar == 'C' || cap->cmdchar == 'D') {
        curwin->w_curswant = MAXCOL;
      }
    }
    cap->cmdchar = *(vim_strchr(trans, cap->cmdchar) + 1);
    nv_operator(cap);
  }
  
  /*
   * "s" and "S" commands.
   */
  static void nv_subst(cmdarg_T *cap)
  {
    if (bt_prompt(curbuf) && !prompt_curpos_editable()) {
      clearopbeep(cap->oap);
      return;
    }
    if (VIsual_active) {  // "vs" and "vS" are the same as "vc"
      if (cap->cmdchar == 'S') {
        VIsual_mode_orig = VIsual_mode;
        VIsual_mode = 'V';
      }
      cap->cmdchar = 'c';
      nv_operator(cap);
    } else {
      nv_optrans(cap);
    }
  }
  
  /*
   * Abbreviated commands.
   */
  static void nv_abbrev(cmdarg_T *cap)
  {
    if (cap->cmdchar == K_DEL || cap->cmdchar == K_KDEL) {
      cap->cmdchar = 'x';                 // DEL key behaves like 'x'
    }
    // in Visual mode these commands are operators
    if (VIsual_active) {
      v_visop(cap);
    } else {
      nv_optrans(cap);
    }
  }
  
  /*
   * Translate a command into another command.
   */
  static void nv_optrans(cmdarg_T *cap)
  {
    static const char *(ar[]) = { "dl", "dh", "d$", "c$", "cl", "cc", "yy",
                                  ":s\r" };
    static const char *str = "xXDCsSY&";
  
    if (!checkclearopq(cap->oap)) {
      if (cap->count0) {
        stuffnumReadbuff(cap->count0);
      }
      stuffReadbuff(ar[strchr(str, (char)cap->cmdchar) - str]);
    }
    cap->opcount = 0;
  }
  
  /*
   * "'" and "`" commands.  Also for "g'" and "g`".
   * cap->arg is true for "'" and "g'".
   */
  static void nv_gomark(cmdarg_T *cap)
  {
    pos_T *pos;
    int c;
    pos_T old_cursor = curwin->w_cursor;
    const bool old_KeyTyped = KeyTyped;       // getting file may reset it
  
    if (cap->cmdchar == 'g') {
      c = cap->extra_char;
    } else {
      c = cap->nchar;
    }
    pos = getmark(c, (cap->oap->op_type == OP_NOP));
    if (pos == (pos_T *)-1) {         // jumped to other file
      if (cap->arg) {
        check_cursor_lnum();
        beginline(BL_WHITE | BL_FIX);
      } else {
        check_cursor();
      }
    } else {
      nv_cursormark(cap, cap->arg, pos);
    }
  
    // May need to clear the coladd that a mark includes.
    if (!virtual_active()) {
      curwin->w_cursor.coladd = 0;
    }
    check_cursor_col();
    if (cap->oap->op_type == OP_NOP
        && pos != NULL
        && (pos == (pos_T *)-1 || !equalpos(old_cursor, *pos))
        && (fdo_flags & FDO_MARK)
        && old_KeyTyped) {
      foldOpenCursor();
    }
  }
  
  // Handle CTRL-O, CTRL-I, "g;", "g,", and "CTRL-Tab" commands.
  static void nv_pcmark(cmdarg_T *cap)
  {
    pos_T *pos;
    linenr_T lnum = curwin->w_cursor.lnum;
    const bool old_KeyTyped = KeyTyped;       // getting file may reset it
  
    if (!checkclearopq(cap->oap)) {
      if (cap->cmdchar == TAB && mod_mask == MOD_MASK_CTRL) {
        goto_tabpage_lastused();
        return;
      }
      if (cap->cmdchar == 'g') {
        pos = movechangelist((int)cap->count1);
      } else {
        pos = movemark((int)cap->count1);
      }
      if (pos == (pos_T *)-1) {           // jump to other file
        curwin->w_set_curswant = true;
        check_cursor();
      } else if (pos != NULL) {               // can jump
        nv_cursormark(cap, false, pos);
      } else if (cap->cmdchar == 'g') {
        if (curbuf->b_changelistlen == 0) {
          emsg(_("E664: changelist is empty"));
        } else if (cap->count1 < 0) {
          emsg(_("E662: At start of changelist"));
        } else {
          emsg(_("E663: At end of changelist"));
        }
      } else {
        clearopbeep(cap->oap);
      }
      if (cap->oap->op_type == OP_NOP
          && (pos == (pos_T *)-1 || lnum != curwin->w_cursor.lnum)
          && (fdo_flags & FDO_MARK)
          && old_KeyTyped) {
        foldOpenCursor();
      }
    }
  }
  
  /*
   * Handle '"' command.
   */
  static void nv_regname(cmdarg_T *cap)
  {
    if (checkclearop(cap->oap)) {
      return;
    }
    if (cap->nchar == '=') {
      cap->nchar = get_expr_register();
    }
    if (cap->nchar != NUL && valid_yank_reg(cap->nchar, false)) {
      cap->oap->regname = cap->nchar;
      cap->opcount = cap->count0;         // remember count before '"'
      set_reg_var(cap->oap->regname);
    } else {
      clearopbeep(cap->oap);
    }
  }
  
  /*
   * Handle "v", "V" and "CTRL-V" commands.
   * Also for "gh", "gH" and "g^H" commands: Always start Select mode, cap->arg
   * is true.
   * Handle CTRL-Q just like CTRL-V.
   */
  static void nv_visual(cmdarg_T *cap)
  {
    if (cap->cmdchar == Ctrl_Q) {
      cap->cmdchar = Ctrl_V;
    }
  
    // 'v', 'V' and CTRL-V can be used while an operator is pending to make it
    // charwise, linewise, or blockwise.
    if (cap->oap->op_type != OP_NOP) {
      motion_force = cap->oap->motion_force = cap->cmdchar;
      finish_op = false;          // operator doesn't finish now but later
      return;
    }
  
    VIsual_select = cap->arg;
    if (VIsual_active) {      // change Visual mode
      if (VIsual_mode == cap->cmdchar) {      // stop visual mode
        end_visual_mode();
      } else {                                  // toggle char/block mode
                                                //           or char/line mode
        VIsual_mode = cap->cmdchar;
        showmode();
        trigger_modechanged();
      }
      redraw_curbuf_later(INVERTED);          // update the inversion
    } else {                // start Visual mode
      if (cap->count0 > 0 && resel_VIsual_mode != NUL) {
        // use previously selected part
        VIsual = curwin->w_cursor;
  
        VIsual_active = true;
        VIsual_reselect = true;
        if (!cap->arg) {
          // start Select mode when 'selectmode' contains "cmd"
          may_start_select('c');
        }
        setmouse();
        if (p_smd && msg_silent == 0) {
          redraw_cmdline = true;              // show visual mode later
        }
        /*
         * For V and ^V, we multiply the number of lines even if there
         * was only one -- webb
         */
        if (resel_VIsual_mode != 'v' || resel_VIsual_line_count > 1) {
          curwin->w_cursor.lnum +=
            resel_VIsual_line_count * cap->count0 - 1;
          if (curwin->w_cursor.lnum > curbuf->b_ml.ml_line_count) {
            curwin->w_cursor.lnum = curbuf->b_ml.ml_line_count;
          }
        }
        VIsual_mode = resel_VIsual_mode;
        if (VIsual_mode == 'v') {
          if (resel_VIsual_line_count <= 1) {
            validate_virtcol();
            assert(cap->count0 >= INT_MIN && cap->count0 <= INT_MAX);
            curwin->w_curswant = (curwin->w_virtcol
                                  + resel_VIsual_vcol * (int)cap->count0 - 1);
          } else {
            curwin->w_curswant = resel_VIsual_vcol;
          }
          coladvance(curwin->w_curswant);
        }
        if (resel_VIsual_vcol == MAXCOL) {
          curwin->w_curswant = MAXCOL;
          coladvance(MAXCOL);
        } else if (VIsual_mode == Ctrl_V) {
          validate_virtcol();
          assert(cap->count0 >= INT_MIN && cap->count0 <= INT_MAX);
          curwin->w_curswant = (curwin->w_virtcol
                                + resel_VIsual_vcol * (int)cap->count0 - 1);
          coladvance(curwin->w_curswant);
        } else {
          curwin->w_set_curswant = true;
        }
        redraw_curbuf_later(INVERTED);            // show the inversion
      } else {
        if (!cap->arg) {
          // start Select mode when 'selectmode' contains "cmd"
          may_start_select('c');
        }
        n_start_visual_mode(cap->cmdchar);
        if (VIsual_mode != 'V' && *p_sel == 'e') {
          ++cap->count1;          // include one more char
        }
        if (cap->count0 > 0 && --cap->count1 > 0) {
          // With a count select that many characters or lines.
          if (VIsual_mode == 'v' || VIsual_mode == Ctrl_V) {
            nv_right(cap);
          } else if (VIsual_mode == 'V') {
            nv_down(cap);
          }
        }
      }
    }
  
    // CUSTOM_UI begin
    ui_cursor_shape();
    // CUSTOM_UI end
  }
  
  /*
   * Start selection for Shift-movement keys.
   */
  void start_selection(void)
  {
    // if 'selectmode' contains "key", start Select mode
    may_start_select('k');
    n_start_visual_mode('v');
  }
  
  /*
   * Start Select mode, if "c" is in 'selectmode' and not in a mapping or menu.
   */
  void may_start_select(int c)
  {
    VIsual_select = (stuff_empty() && typebuf_typed()
                     && (vim_strchr(p_slm, c) != NULL));
  }
  
  /*
   * Start Visual mode "c".
   * Should set VIsual_select before calling this.
   */
  static void n_start_visual_mode(int c)
  {
    VIsual_mode = c;
    VIsual_active = true;
    VIsual_reselect = true;
    // Corner case: the 0 position in a tab may change when going into
    // virtualedit.  Recalculate curwin->w_cursor to avoid bad highlighting.
    //
    if (c == Ctrl_V && (ve_flags & VE_BLOCK) && gchar_cursor() == TAB) {
      validate_virtcol();
      coladvance(curwin->w_virtcol);
    }
    VIsual = curwin->w_cursor;
  
    foldAdjustVisual();
  
    trigger_modechanged();
    setmouse();
    // Check for redraw after changing the state.
    conceal_check_cursor_line();
  
    if (p_smd && msg_silent == 0) {
      redraw_cmdline = true;      // show visual mode later
    }
    // Only need to redraw this line, unless still need to redraw an old
    // Visual area (when 'lazyredraw' is set).
    if (curwin->w_redr_type < INVERTED) {
      curwin->w_old_cursor_lnum = curwin->w_cursor.lnum;
      curwin->w_old_visual_lnum = curwin->w_cursor.lnum;
    }
  }
  
  
  /*
   * CTRL-W: Window commands
   */
  static void nv_window(cmdarg_T *cap)
  {
    if (cap->nchar == ':') {
      // "CTRL-W :" is the same as typing ":"; useful in a terminal window
      cap->cmdchar = ':';
      cap->nchar = NUL;
      nv_colon(cap);
    } else if (!checkclearop(cap->oap)) {
      do_window(cap->nchar, cap->count0, NUL);  // everything is in window.c
    }
  }
  
  /*
   * CTRL-Z: Suspend
   */
  static void nv_suspend(cmdarg_T *cap)
  {
    clearop(cap->oap);
    if (VIsual_active) {
      end_visual_mode();                  // stop Visual mode
    }
    do_cmdline_cmd("st");
  }
  
  /*
   * Commands starting with "g".
   */
  static void nv_g_cmd(cmdarg_T *cap)
  {
    oparg_T *oap = cap->oap;
    pos_T tpos;
    int i;
    bool flag = false;
  
    switch (cap->nchar) {
    // "g^A/g^X": Sequentially increment visually selected region.
    case Ctrl_A:
    case Ctrl_X:
      if (VIsual_active) {
        cap->arg = true;
        cap->cmdchar = cap->nchar;
        cap->nchar = NUL;
        nv_addsub(cap);
      } else {
        clearopbeep(oap);
      }
      break;
  
    // "gR": Enter virtual replace mode.
    case 'R':
      cap->arg = true;
      nv_Replace(cap);
      break;
  
    case 'r':
      nv_vreplace(cap);
      break;
  
    case '&':
      do_cmdline_cmd("%s//~/&");
      break;
  
    /*
     * "gv": Reselect the previous Visual area.  If Visual already active,
     *         exchange previous and current Visual area.
     */
    case 'v':
      if (checkclearop(oap)) {
        break;
      }
  
      if (curbuf->b_visual.vi_start.lnum == 0
          || curbuf->b_visual.vi_start.lnum > curbuf->b_ml.ml_line_count
          || curbuf->b_visual.vi_end.lnum == 0) {
        beep_flush();
      } else {
        // set w_cursor to the start of the Visual area, tpos to the end
        if (VIsual_active) {
          i = VIsual_mode;
          VIsual_mode = curbuf->b_visual.vi_mode;
          curbuf->b_visual.vi_mode = i;
          curbuf->b_visual_mode_eval = i;
          i = curwin->w_curswant;
          curwin->w_curswant = curbuf->b_visual.vi_curswant;
          curbuf->b_visual.vi_curswant = i;
  
          tpos = curbuf->b_visual.vi_end;
          curbuf->b_visual.vi_end = curwin->w_cursor;
          curwin->w_cursor = curbuf->b_visual.vi_start;
          curbuf->b_visual.vi_start = VIsual;
        } else {
          VIsual_mode = curbuf->b_visual.vi_mode;
          curwin->w_curswant = curbuf->b_visual.vi_curswant;
          tpos = curbuf->b_visual.vi_end;
          curwin->w_cursor = curbuf->b_visual.vi_start;
        }
  
        VIsual_active = true;
        VIsual_reselect = true;
  
        // Set Visual to the start and w_cursor to the end of the Visual
        // area.  Make sure they are on an existing character.
        check_cursor();
        VIsual = curwin->w_cursor;
        curwin->w_cursor = tpos;
        check_cursor();
        update_topline(curwin);
        // When called from normal "g" command: start Select mode when
        // 'selectmode' contains "cmd".  When called for K_SELECT, always
        // start Select mode.
        if (cap->arg) {
          VIsual_select = true;
        } else {
          may_start_select('c');
        }
        setmouse();
        redraw_curbuf_later(INVERTED);
        showmode();
      }
      break;
    /*
     * "gV": Don't reselect the previous Visual area after a Select mode
     *         mapping of menu.
     */
    case 'V':
      VIsual_reselect = false;
      break;
  
    /*
     * "gh":  start Select mode.
     * "gH":  start Select line mode.
     * "g^H": start Select block mode.
     */
    case K_BS:
      cap->nchar = Ctrl_H;
      FALLTHROUGH;
    case 'h':
    case 'H':
    case Ctrl_H:
      cap->cmdchar = cap->nchar + ('v' - 'h');
      cap->arg = true;
      nv_visual(cap);
      break;
  
    // "gn", "gN" visually select next/previous search match
    // "gn" selects next match
    // "gN" selects previous match
    case 'N':
    case 'n':
      if (!current_search(cap->count1, cap->nchar == 'n')) {
        clearopbeep(oap);
      }
      break;
  
    /*
     * "gj" and "gk" two new funny movement keys -- up and down
     * movement based on *screen* line rather than *file* line.
     */
    case 'j':
    case K_DOWN:
      // with 'nowrap' it works just like the normal "j" command.
      if (!curwin->w_p_wrap) {
        oap->motion_type = kMTLineWise;
        i = cursor_down(cap->count1, oap->op_type == OP_NOP);
      } else {
        i = nv_screengo(oap, FORWARD, cap->count1);
      }
      if (!i) {
        clearopbeep(oap);
      }
      break;
  
    case 'k':
    case K_UP:
      // with 'nowrap' it works just like the normal "k" command.
      if (!curwin->w_p_wrap) {
        oap->motion_type = kMTLineWise;
        i = cursor_up(cap->count1, oap->op_type == OP_NOP);
      } else {
        i = nv_screengo(oap, BACKWARD, cap->count1);
      }
      if (!i) {
        clearopbeep(oap);
      }
      break;
  
    /*
     * "gJ": join two lines without inserting a space.
     */
    case 'J':
      nv_join(cap);
      break;
  
    /*
     * "g0", "g^" and "g$": Like "0", "^" and "$" but for screen lines.
     * "gm": middle of "g0" and "g$".
     */
    case '^':
      flag = true;
      FALLTHROUGH;
  
    case '0':
    case 'm':
    case K_HOME:
    case K_KHOME:
      oap->motion_type = kMTCharWise;
      oap->inclusive = false;
      if (curwin->w_p_wrap
          && curwin->w_width_inner != 0) {
        int width1 = curwin->w_width_inner - curwin_col_off();
        int width2 = width1 + curwin_col_off2();
  
        validate_virtcol();
        i = 0;
        if (curwin->w_virtcol >= (colnr_T)width1 && width2 > 0) {
          i = (curwin->w_virtcol - width1) / width2 * width2 + width1;
        }
      } else {
        i = curwin->w_leftcol;
      }
      // Go to the middle of the screen line.  When 'number' or
      // 'relativenumber' is on and lines are wrapping the middle can be more
      // to the left.
      if (cap->nchar == 'm') {
        i += (curwin->w_width_inner - curwin_col_off()
              + ((curwin->w_p_wrap && i > 0)
                 ? curwin_col_off2() : 0)) / 2;
      }
      coladvance((colnr_T)i);
      if (flag) {
        do {
          i = gchar_cursor();
        } while (ascii_iswhite(i) && oneright());
        curwin->w_valid &= ~VALID_WCOL;
      }
      curwin->w_set_curswant = true;
      break;
  
    case 'M': {
      const char_u *const ptr = get_cursor_line_ptr();
  
      oap->motion_type = kMTCharWise;
      oap->inclusive = false;
      i = (int)mb_string2cells_len(ptr, STRLEN(ptr));
      if (cap->count0 > 0 && cap->count0 <= 100) {
        coladvance((colnr_T)(i * cap->count0 / 100));
      } else {
        coladvance((colnr_T)(i / 2));
      }
      curwin->w_set_curswant = true;
    }
    break;
  
    case '_':
      /* "g_": to the last non-blank character in the line or <count> lines
       * downward. */
      cap->oap->motion_type = kMTCharWise;
      cap->oap->inclusive = true;
      curwin->w_curswant = MAXCOL;
      if (cursor_down(cap->count1 - 1,
                      cap->oap->op_type == OP_NOP) == false) {
        clearopbeep(cap->oap);
      } else {
        char_u *ptr = get_cursor_line_ptr();
  
        // In Visual mode we may end up after the line.
        if (curwin->w_cursor.col > 0 && ptr[curwin->w_cursor.col] == NUL) {
          --curwin->w_cursor.col;
        }
  
        // Decrease the cursor column until it's on a non-blank.
        while (curwin->w_cursor.col > 0
               && ascii_iswhite(ptr[curwin->w_cursor.col])) {
          --curwin->w_cursor.col;
        }
        curwin->w_set_curswant = true;
        adjust_for_sel(cap);
      }
      break;
  
    case '$':
    case K_END:
    case K_KEND: {
      int col_off = curwin_col_off();
  
      oap->motion_type = kMTCharWise;
      oap->inclusive = true;
      if (curwin->w_p_wrap
          && curwin->w_width_inner != 0) {
        curwin->w_curswant = MAXCOL;              // so we stay at the end
        if (cap->count1 == 1) {
          int width1 = curwin->w_width_inner - col_off;
          int width2 = width1 + curwin_col_off2();
  
          validate_virtcol();
          i = width1 - 1;
          if (curwin->w_virtcol >= (colnr_T)width1) {
            i += ((curwin->w_virtcol - width1) / width2 + 1)
                 * width2;
          }
          coladvance((colnr_T)i);
  
          // Make sure we stick in this column.
          validate_virtcol();
          curwin->w_curswant = curwin->w_virtcol;
          curwin->w_set_curswant = false;
          if (curwin->w_cursor.col > 0 && curwin->w_p_wrap) {
            /*
             * Check for landing on a character that got split at
             * the end of the line.  We do not want to advance to
             * the next screen line.
             */
            if (curwin->w_virtcol > (colnr_T)i) {
              --curwin->w_cursor.col;
            }
          }
        } else if (nv_screengo(oap, FORWARD, cap->count1 - 1) == false) {
          clearopbeep(oap);
        }
      } else {
        if (cap->count1 > 1) {
          // if it fails, let the cursor still move to the last char
          (void)cursor_down(cap->count1 - 1, false);
        }
        i = curwin->w_leftcol + curwin->w_width_inner - col_off - 1;
        coladvance((colnr_T)i);
  
        // Make sure we stick in this column.
        validate_virtcol();
        curwin->w_curswant = curwin->w_virtcol;
        curwin->w_set_curswant = false;
      }
    }
    break;
  
    /*
     * "g*" and "g#", like "*" and "#" but without using "\<" and "\>"
     */
    case '*':
    case '#':
  #if POUND != '#'
    case POUND:           // pound sign (sometimes equal to '#')
  #endif
    case Ctrl_RSB:                // :tag or :tselect for current identifier
    case ']':                     // :tselect for current identifier
      nv_ident(cap);
      break;
  
    /*
     * ge and gE: go back to end of word
     */
    case 'e':
    case 'E':
      oap->motion_type = kMTCharWise;
      curwin->w_set_curswant = true;
      oap->inclusive = true;
      if (bckend_word(cap->count1, cap->nchar == 'E', false) == false) {
        clearopbeep(oap);
      }
      break;
  
    // "g CTRL-G": display info about cursor position
    case Ctrl_G:
      cursor_pos_info(NULL);
      break;
  
    // "gi": start Insert at the last position.
    case 'i':
      if (curbuf->b_last_insert.mark.lnum != 0) {
        curwin->w_cursor = curbuf->b_last_insert.mark;
        check_cursor_lnum();
        i = (int)STRLEN(get_cursor_line_ptr());
        if (curwin->w_cursor.col > (colnr_T)i) {
          if (virtual_active()) {
            curwin->w_cursor.coladd += curwin->w_cursor.col - i;
          }
          curwin->w_cursor.col = i;
        }
      }
      cap->cmdchar = 'i';
      nv_edit(cap);
      break;
  
    /*
     * "gI": Start insert in column 1.
     */
    case 'I':
      beginline(0);
      if (!checkclearopq(oap)) {
        invoke_edit(cap, false, 'g', false);
      }
      break;
  
    /*
     * "gf": goto file, edit file under cursor
     * "]f" and "[f": can also be used.
     */
    case 'f':
    case 'F':
      nv_gotofile(cap);
      break;
  
    // "g'm" and "g`m": jump to mark without setting pcmark
    case '\'':
      cap->arg = true;
      FALLTHROUGH;
    case '`':
      nv_gomark(cap);
      break;
  
    /*
     * "gs": Goto sleep.
     */
    case 's':
      do_sleep(cap->count1 * 1000L);
      break;
  
    /*
     * "ga": Display the ascii value of the character under the
     * cursor.    It is displayed in decimal, hex, and octal. -- webb
     */
    case 'a':
      do_ascii(NULL);
      break;
  
    /*
     * "g8": Display the bytes used for the UTF-8 character under the
     * cursor.    It is displayed in hex.
     * "8g8" finds illegal byte sequence.
     */
    case '8':
      if (cap->count0 == 8) {
        utf_find_illegal();
      } else {
        show_utf8();
      }
      break;
    // "g<": show scrollback text
    case '<':
      show_sb_text();
      break;
  
    /*
     * "gg": Goto the first line in file.  With a count it goes to
     * that line number like for "G". -- webb
     */
    case 'g':
      cap->arg = false;
      nv_goto(cap);
      break;
  
    /*
     *     Two-character operators:
     *     "gq"       Format text
     *     "gw"       Format text and keep cursor position
     *     "g~"       Toggle the case of the text.
     *     "gu"       Change text to lower case.
     *     "gU"       Change text to upper case.
     *   "g?"         rot13 encoding
     *   "g@"         call 'operatorfunc'
     */
    case 'q':
    case 'w':
      oap->cursor_start = curwin->w_cursor;
      FALLTHROUGH;
    case '~':
    case 'u':
    case 'U':
    case '?':
    case '@':
      nv_operator(cap);
      break;
  
    /*
     * "gd": Find first occurrence of pattern under the cursor in the
     *     current function
     * "gD": idem, but in the current file.
     */
    case 'd':
    case 'D':
      nv_gd(oap, cap->nchar, (int)cap->count0);
      break;
  
    /*
     * g<*Mouse> : <C-*mouse>
     */
    case K_MIDDLEMOUSE:
    case K_MIDDLEDRAG:
    case K_MIDDLERELEASE:
    case K_LEFTMOUSE:
    case K_LEFTDRAG:
    case K_LEFTRELEASE:
    case K_MOUSEMOVE:
    case K_RIGHTMOUSE:
    case K_RIGHTDRAG:
    case K_RIGHTRELEASE:
    case K_X1MOUSE:
    case K_X1DRAG:
    case K_X1RELEASE:
    case K_X2MOUSE:
    case K_X2DRAG:
    case K_X2RELEASE:
      mod_mask = MOD_MASK_CTRL;
      (void)do_mouse(oap, cap->nchar, BACKWARD, cap->count1, 0);
      break;
  
    case K_IGNORE:
      break;
  
    /*
     * "gP" and "gp": same as "P" and "p" but leave cursor just after new text
     */
    case 'p':
    case 'P':
      nv_put(cap);
      break;
  
    // "go": goto byte count from start of buffer
    case 'o':
      goto_byte(cap->count0);
      break;
  
    // "gQ": improved Ex mode
    case 'Q':
      if (text_locked()) {
        clearopbeep(cap->oap);
        text_locked_msg();
        break;
      }
  
      if (!checkclearopq(oap)) {
        do_exmode();
      }
      break;
  
    case ',':
      nv_pcmark(cap);
      break;
  
    case ';':
      cap->count1 = -cap->count1;
      nv_pcmark(cap);
      break;
  
    case 't':
      if (!checkclearop(oap)) {
        goto_tabpage((int)cap->count0);
      }
      break;
    case 'T':
      if (!checkclearop(oap)) {
        goto_tabpage(-(int)cap->count1);
      }
      break;
    case TAB:
      if (!checkclearop(oap)) {
        goto_tabpage_lastused();
      }
      break;
  
    case '+':
    case '-':   // "g+" and "g-": undo or redo along the timeline
      if (!checkclearopq(oap)) {
        undo_time(cap->nchar == '-' ? -cap->count1 : cap->count1,
                  false, false, false);
      }
      break;
  
    default:
      clearopbeep(oap);
      break;
    }
  }
  
  /*
   * Handle "o" and "O" commands.
   */
  static void n_opencmd(cmdarg_T *cap)
  {
    if (!checkclearopq(cap->oap)) {
      if (cap->cmdchar == 'O') {
        // Open above the first line of a folded sequence of lines
        (void)hasFolding(curwin->w_cursor.lnum,
                         &curwin->w_cursor.lnum, NULL);
      } else {
        // Open below the last line of a folded sequence of lines
        (void)hasFolding(curwin->w_cursor.lnum,
                         NULL, &curwin->w_cursor.lnum);
      }
      if (u_save((linenr_T)(curwin->w_cursor.lnum -
                            (cap->cmdchar == 'O' ? 1 : 0)),
                 (linenr_T)(curwin->w_cursor.lnum +
                            (cap->cmdchar == 'o' ? 1 : 0))
                 )
          && open_line(cap->cmdchar == 'O' ? BACKWARD : FORWARD,
                       has_format_option(FO_OPEN_COMS)
                       ? OPENLINE_DO_COM : 0,
                       0)) {
        if (win_cursorline_standout(curwin)) {
          // force redraw of cursorline
          curwin->w_valid &= ~VALID_CROW;
        }
        invoke_edit(cap, false, cap->cmdchar, true);
      }
    }
  }
  
  /*
   * "." command: redo last change.
   */
  static void nv_dot(cmdarg_T *cap)
  {
    if (!checkclearopq(cap->oap)) {
      /*
       * If "restart_edit" is true, the last but one command is repeated
       * instead of the last command (inserting text). This is used for
       * CTRL-O <.> in insert mode.
       */
      if (start_redo(cap->count0, restart_edit != 0 && !arrow_used) == false) {
        clearopbeep(cap->oap);
      }
    }
  }
  
  /*
   * CTRL-R: undo undo
   */
  static void nv_redo(cmdarg_T *cap)
  {
    if (!checkclearopq(cap->oap)) {
      u_redo((int)cap->count1);
      curwin->w_set_curswant = true;
    }
  }
  
  /*
   * Handle "U" command.
   */
  static void nv_Undo(cmdarg_T *cap)
  {
    // In Visual mode and typing "gUU" triggers an operator
    if (cap->oap->op_type == OP_UPPER
        || VIsual_active) {
      // translate "gUU" to "gUgU"
      cap->cmdchar = 'g';
      cap->nchar = 'U';
      nv_operator(cap);
    } else if (!checkclearopq(cap->oap)) {
      u_undoline();
      curwin->w_set_curswant = true;
    }
  }
  
  /*
   * '~' command: If tilde is not an operator and Visual is off: swap case of a
   * single character.
   */
  static void nv_tilde(cmdarg_T *cap)
  {
    if (!p_to
        && !VIsual_active
        && cap->oap->op_type != OP_TILDE) {
      if (bt_prompt(curbuf) && !prompt_curpos_editable()) {
        clearopbeep(cap->oap);
        return;
      }
      n_swapchar(cap);
    } else {
      nv_operator(cap);
    }
  }
  
  /*
   * Handle an operator command.
   * The actual work is done by do_pending_operator().
   */
  static void nv_operator(cmdarg_T *cap)
  {
    int op_type;
  
    op_type = get_op_type(cap->cmdchar, cap->nchar);
  
    if (bt_prompt(curbuf) && op_is_change(op_type)
        && !prompt_curpos_editable()) {
      clearopbeep(cap->oap);
      return;
    }
  
    if (op_type == cap->oap->op_type) {       // double operator works on lines
      nv_lineop(cap);
    } else if (!checkclearop(cap->oap)) {
      cap->oap->start = curwin->w_cursor;
      cap->oap->op_type = op_type;
      set_op_var(op_type);
    }
  }
  
  /*
   * Set v:operator to the characters for "optype".
   */
  static void set_op_var(int optype)
  {
    if (optype == OP_NOP) {
      set_vim_var_string(VV_OP, NULL, 0);
    } else {
      char opchars[3];
      int opchar0 = get_op_char(optype);
      assert(opchar0 >= 0 && opchar0 <= UCHAR_MAX);
      opchars[0] = (char)opchar0;
  
      int opchar1 = get_extra_op_char(optype);
      assert(opchar1 >= 0 && opchar1 <= UCHAR_MAX);
      opchars[1] = (char)opchar1;
  
      opchars[2] = NUL;
      set_vim_var_string(VV_OP, opchars, -1);
    }
  }
  
  /*
   * Handle linewise operator "dd", "yy", etc.
   *
   * "_" is is a strange motion command that helps make operators more logical.
   * It is actually implemented, but not documented in the real Vi.  This motion
   * command actually refers to "the current line".  Commands like "dd" and "yy"
   * are really an alternate form of "d_" and "y_".  It does accept a count, so
   * "d3_" works to delete 3 lines.
   */
  static void nv_lineop(cmdarg_T *cap)
  {
    cap->oap->motion_type = kMTLineWise;
    if (cursor_down(cap->count1 - 1L, cap->oap->op_type == OP_NOP) == false) {
      clearopbeep(cap->oap);
    } else if ((cap->oap->op_type == OP_DELETE
                // only with linewise motions
                && cap->oap->motion_force != 'v'
                && cap->oap->motion_force != Ctrl_V)
               || cap->oap->op_type == OP_LSHIFT
               || cap->oap->op_type == OP_RSHIFT) {
      beginline(BL_SOL | BL_FIX);
    } else if (cap->oap->op_type != OP_YANK) {  // 'Y' does not move cursor
      beginline(BL_WHITE | BL_FIX);
    }
  }
  
  /*
   * <Home> command.
   */
  static void nv_home(cmdarg_T *cap)
  {
    // CTRL-HOME is like "gg"
    if (mod_mask & MOD_MASK_CTRL) {
      nv_goto(cap);
    } else {
      cap->count0 = 1;
      nv_pipe(cap);
    }
    ins_at_eol = false;       // Don't move cursor past eol (only necessary in a
                              // one-character line).
  }
  
  /*
   * "|" command.
   */
  static void nv_pipe(cmdarg_T *cap)
  {
    cap->oap->motion_type = kMTCharWise;
    cap->oap->inclusive = false;
    beginline(0);
    if (cap->count0 > 0) {
      coladvance((colnr_T)(cap->count0 - 1));
      curwin->w_curswant = (colnr_T)(cap->count0 - 1);
    } else {
      curwin->w_curswant = 0;
    }
    // keep curswant at the column where we wanted to go, not where
    // we ended; differs if line is too short
    curwin->w_set_curswant = false;
  }
  
  /*
   * Handle back-word command "b" and "B".
   * cap->arg is 1 for "B"
   */
  static void nv_bck_word(cmdarg_T *cap)
  {
    cap->oap->motion_type = kMTCharWise;
    cap->oap->inclusive = false;
    curwin->w_set_curswant = true;
    if (bck_word(cap->count1, cap->arg, false) == false) {
      clearopbeep(cap->oap);
    } else if ((fdo_flags & FDO_HOR) && KeyTyped && cap->oap->op_type == OP_NOP) {
      foldOpenCursor();
    }
  }
  
  /*
   * Handle word motion commands "e", "E", "w" and "W".
   * cap->arg is true for "E" and "W".
   */
  static void nv_wordcmd(cmdarg_T *cap)
  {
    int n;
    bool word_end;
    bool flag = false;
    pos_T startpos = curwin->w_cursor;
  
    /*
     * Set inclusive for the "E" and "e" command.
     */
    if (cap->cmdchar == 'e' || cap->cmdchar == 'E') {
      word_end = true;
    } else {
      word_end = false;
    }
    cap->oap->inclusive = word_end;
  
    /*
     * "cw" and "cW" are a special case.
     */
    if (!word_end && cap->oap->op_type == OP_CHANGE) {
      n = gchar_cursor();
      if (n != NUL && !ascii_iswhite(n)) {
        // This is a little strange.  To match what the real Vi does, we
        // effectively map "cw" to "ce", and "cW" to "cE", provided that we are
        // not on a space or a TAB.  This seems impolite at first, but it's
        // really more what we mean when we say "cw".
        //
        // Another strangeness: When standing on the end of a word "ce" will
        // change until the end of the next word, but "cw" will change only one
        // character!  This is done by setting "flag".
        if (vim_strchr(p_cpo, CPO_CHANGEW) != NULL) {
          cap->oap->inclusive = true;
          word_end = true;
        }
        flag = true;
      }
    }
  
    cap->oap->motion_type = kMTCharWise;
    curwin->w_set_curswant = true;
    if (word_end) {
      n = end_word(cap->count1, cap->arg, flag, false);
    } else {
      n = fwd_word(cap->count1, cap->arg, cap->oap->op_type != OP_NOP);
    }
  
    // Don't leave the cursor on the NUL past the end of line. Unless we
    // didn't move it forward.
    if (lt(startpos, curwin->w_cursor)) {
      adjust_cursor(cap->oap);
    }
  
    if (n == false && cap->oap->op_type == OP_NOP) {
      clearopbeep(cap->oap);
    } else {
      adjust_for_sel(cap);
      if ((fdo_flags & FDO_HOR) && KeyTyped && cap->oap->op_type == OP_NOP) {
        foldOpenCursor();
      }
    }
  }
  
  /*
   * Used after a movement command: If the cursor ends up on the NUL after the
   * end of the line, may move it back to the last character and make the motion
   * inclusive.
   */
  static void adjust_cursor(oparg_T *oap)
  {
    // The cursor cannot remain on the NUL when:
    // - the column is > 0
    // - not in Visual mode or 'selection' is "o"
    // - 'virtualedit' is not "all" and not "onemore".
    if (curwin->w_cursor.col > 0 && gchar_cursor() == NUL
        && (!VIsual_active || *p_sel == 'o')
        && !virtual_active()
        && (ve_flags & VE_ONEMORE) == 0) {
      curwin->w_cursor.col--;
      // prevent cursor from moving on the trail byte
      mb_adjust_cursor();
      oap->inclusive = true;
    }
  }
  
  /*
   * "0" and "^" commands.
   * cap->arg is the argument for beginline().
   */
  static void nv_beginline(cmdarg_T *cap)
  {
    cap->oap->motion_type = kMTCharWise;
    cap->oap->inclusive = false;
    beginline(cap->arg);
    if ((fdo_flags & FDO_HOR) && KeyTyped && cap->oap->op_type == OP_NOP) {
      foldOpenCursor();
    }
    ins_at_eol = false;       // Don't move cursor past eol (only necessary in a
                              // one-character line).
  }
  
  /*
   * In exclusive Visual mode, may include the last character.
   */
  static void adjust_for_sel(cmdarg_T *cap)
  {
    if (VIsual_active && cap->oap->inclusive && *p_sel == 'e'
        && gchar_cursor() != NUL && lt(VIsual, curwin->w_cursor)) {
      inc_cursor();
      cap->oap->inclusive = false;
    }
  }
  
  /*
   * Exclude last character at end of Visual area for 'selection' == "exclusive".
   * Should check VIsual_mode before calling this.
   * Returns true when backed up to the previous line.
   */
  static bool unadjust_for_sel(void)
  {
    pos_T *pp;
  
    if (*p_sel == 'e' && !equalpos(VIsual, curwin->w_cursor)) {
      if (lt(VIsual, curwin->w_cursor)) {
        pp = &curwin->w_cursor;
      } else {
        pp = &VIsual;
      }
      if (pp->coladd > 0) {
        pp->coladd--;
      } else if (pp->col > 0) {
        pp->col--;
        mark_mb_adjustpos(curbuf, pp);
      } else if (pp->lnum > 1) {
        --pp->lnum;
        pp->col = (colnr_T)STRLEN(ml_get(pp->lnum));
        return true;
      }
    }
    return false;
  }
  
  /*
   * SELECT key in Normal or Visual mode: end of Select mode mapping.
   */
  static void nv_select(cmdarg_T *cap)
  {
    if (VIsual_active) {
      VIsual_select = true;
    } else if (VIsual_reselect) {
      cap->nchar = 'v';               // fake "gv" command
      cap->arg = true;
      nv_g_cmd(cap);
    }
  }
  
  
  /*
   * "G", "gg", CTRL-END, CTRL-HOME.
   * cap->arg is true for "G".
   */
  static void nv_goto(cmdarg_T *cap)
  {
    linenr_T lnum;
  
    if (cap->arg) {
      lnum = curbuf->b_ml.ml_line_count;
    } else {
      lnum = 1L;
    }
    cap->oap->motion_type = kMTLineWise;
    setpcmark();
  
    // When a count is given, use it instead of the default lnum
    if (cap->count0 != 0) {
      lnum = cap->count0;
    }
    if (lnum < 1L) {
      lnum = 1L;
    } else if (lnum > curbuf->b_ml.ml_line_count) {
      lnum = curbuf->b_ml.ml_line_count;
    }
    curwin->w_cursor.lnum = lnum;
    beginline(BL_SOL | BL_FIX);
    if ((fdo_flags & FDO_JUMP) && KeyTyped && cap->oap->op_type == OP_NOP) {
      foldOpenCursor();
    }
  }
  
  /*
   * CTRL-\ in Normal mode.
   */
  static void nv_normal(cmdarg_T *cap)
  {
    if (cap->nchar == Ctrl_N || cap->nchar == Ctrl_G) {
      clearop(cap->oap);
      if (restart_edit != 0 && mode_displayed) {
        clear_cmdline = true;                     // unshow mode later
      }
      restart_edit = 0;
      if (cmdwin_type != 0) {
        cmdwin_result = Ctrl_C;
      }
      if (VIsual_active) {
        end_visual_mode();                // stop Visual
        redraw_curbuf_later(INVERTED);
      }
      // CTRL-\ CTRL-G restarts Insert mode when 'insertmode' is set.
      if (cap->nchar == Ctrl_G && p_im) {
        restart_edit = 'a';
      }
    } else {
      clearopbeep(cap->oap);
    }
  }
  
  /*
   * ESC in Normal mode: beep, but don't flush buffers.
   * Don't even beep if we are canceling a command.
   */
  static void nv_esc(cmdarg_T *cap)
  {
    int no_reason;
  
    no_reason = (cap->oap->op_type == OP_NOP
                 && cap->opcount == 0
                 && cap->count0 == 0
                 && cap->oap->regname == 0
                 && !p_im);
  
    if (cap->arg) {               // true for CTRL-C
      if (restart_edit == 0
          && cmdwin_type == 0
          && !VIsual_active
          && no_reason) {
        if (anyBufIsChanged()) {
          msg(_("Type  :qa!  and press <Enter> to abandon all changes"
                " and exit Nvim"));
        } else {
          msg(_("Type  :qa  and press <Enter> to exit Nvim"));
        }
      }
  
      // Don't reset "restart_edit" when 'insertmode' is set, it won't be
      // set again below when halfway through a mapping.
      if (!p_im) {
        restart_edit = 0;
      }
      if (cmdwin_type != 0) {
        cmdwin_result = K_IGNORE;
        got_int = false;          // don't stop executing autocommands et al.
        return;
      }
    } else if (cmdwin_type != 0 && ex_normal_busy) {
      // When :normal runs out of characters while in the command line window
      // vgetorpeek() will return ESC.  Exit the cmdline window to break the
      // loop.
      cmdwin_result = K_IGNORE;
      return;
    }
  
    if (VIsual_active) {
      end_visual_mode();          // stop Visual
      check_cursor_col();         // make sure cursor is not beyond EOL
      curwin->w_set_curswant = true;
      redraw_curbuf_later(INVERTED);
    } else if (no_reason) {
      vim_beep(BO_ESC);
    }
    clearop(cap->oap);
  
    // A CTRL-C is often used at the start of a menu.  When 'insertmode' is
    // set return to Insert mode afterwards.
    if (restart_edit == 0 && goto_im()
        && ex_normal_busy == 0) {
      restart_edit = 'a';
    }
  }
  
  // Move the cursor for the "A" command.
  void set_cursor_for_append_to_line(void)
  {
    curwin->w_set_curswant = true;
    if (ve_flags == VE_ALL) {
      const int save_State = State;
  
      // Pretend Insert mode here to allow the cursor on the
      // character past the end of the line
      State = INSERT;
      coladvance(MAXCOL);
      State = save_State;
    } else {
      curwin->w_cursor.col += (colnr_T)STRLEN(get_cursor_pos_ptr());
    }
  }
  
  /// Handle "A", "a", "I", "i" and <Insert> commands.
  static void nv_edit(cmdarg_T *cap)
  {
    // <Insert> is equal to "i"
    if (cap->cmdchar == K_INS || cap->cmdchar == K_KINS) {
      cap->cmdchar = 'i';
    }
  
    // in Visual mode "A" and "I" are an operator
    if (VIsual_active && (cap->cmdchar == 'A' || cap->cmdchar == 'I')) {
      v_visop(cap);
      // in Visual mode and after an operator "a" and "i" are for text objects
    } else if ((cap->cmdchar == 'a' || cap->cmdchar == 'i')
               && (cap->oap->op_type != OP_NOP || VIsual_active)) {
      nv_object(cap);
    } else if (!curbuf->b_p_ma && !p_im && !curbuf->terminal) {
      // Only give this error when 'insertmode' is off.
      emsg(_(e_modifiable));
      clearop(cap->oap);
    } else if (!checkclearopq(cap->oap)) {
      switch (cap->cmdchar) {
      case 'A':           // "A"ppend after the line
        set_cursor_for_append_to_line();
        break;
  
      case 'I':           // "I"nsert before the first non-blank
        beginline(BL_WHITE);
        break;
  
      case 'a':           // "a"ppend is like "i"nsert on the next character.
        // increment coladd when in virtual space, increment the
        // column otherwise, also to append after an unprintable char
        if (virtual_active()
            && (curwin->w_cursor.coladd > 0
                || *get_cursor_pos_ptr() == NUL
                || *get_cursor_pos_ptr() == TAB)) {
          curwin->w_cursor.coladd++;
        } else if (*get_cursor_pos_ptr() != NUL) {
          inc_cursor();
        }
        break;
      }
  
      if (curwin->w_cursor.coladd && cap->cmdchar != 'A') {
        int save_State = State;
  
        // Pretend Insert mode here to allow the cursor on the
        // character past the end of the line
        State = INSERT;
        coladvance(getviscol());
        State = save_State;
      }
  
      invoke_edit(cap, false, cap->cmdchar, false);
    }
  }
  
  /// Invoke edit() and take care of "restart_edit" and the return value.
  ///
  /// @param repl  "r" or "gr" command
  static void invoke_edit(cmdarg_T *cap, int repl, int cmd, int startln)
  {
    int restart_edit_save = 0;
  
    // Complicated: When the user types "a<C-O>a" we don't want to do Insert
    // mode recursively.  But when doing "a<C-O>." or "a<C-O>rx" we do allow
    // it.
    if (repl || !stuff_empty()) {
      restart_edit_save = restart_edit;
    } else {
      restart_edit_save = 0;
    }
  
    // Always reset "restart_edit", this is not a restarted edit.
    restart_edit = 0;
  
    if (edit(cmd, startln, cap->count1)) {
      cap->retval |= CA_COMMAND_BUSY;
    }
  
    if (restart_edit == 0) {
      restart_edit = restart_edit_save;
    }
  }
  
  /*
   * "a" or "i" while an operator is pending or in Visual mode: object motion.
   */
  static void nv_object(cmdarg_T *cap)
  {
    bool flag;
    bool include;
    char_u *mps_save;
  
    if (cap->cmdchar == 'i') {
      include = false;        // "ix" = inner object: exclude white space
    } else {
      include = true;         // "ax" = an object: include white space
    }
    // Make sure (), [], {} and <> are in 'matchpairs'
    mps_save = curbuf->b_p_mps;
    curbuf->b_p_mps = (char_u *)"(:),{:},[:],<:>";
  
    switch (cap->nchar) {
    case 'w':       // "aw" = a word
      flag = current_word(cap->oap, cap->count1, include, false);
      break;
    case 'W':       // "aW" = a WORD
      flag = current_word(cap->oap, cap->count1, include, true);
      break;
    case 'b':       // "ab" = a braces block
    case '(':
    case ')':
      flag = current_block(cap->oap, cap->count1, include, '(', ')');
      break;
    case 'B':       // "aB" = a Brackets block
    case '{':
    case '}':
      flag = current_block(cap->oap, cap->count1, include, '{', '}');
      break;
    case '[':       // "a[" = a [] block
    case ']':
      flag = current_block(cap->oap, cap->count1, include, '[', ']');
      break;
    case '<':       // "a<" = a <> block
    case '>':
      flag = current_block(cap->oap, cap->count1, include, '<', '>');
      break;
    case 't':       // "at" = a tag block (xml and html)
      // Do not adjust oap->end in do_pending_operator()
      // otherwise there are different results for 'dit'
      // (note leading whitespace in last line):
      // 1) <b>      2) <b>
      //    foobar      foobar
      //    </b>            </b>
      cap->retval |= CA_NO_ADJ_OP_END;
      flag = current_tagblock(cap->oap, cap->count1, include);
      break;
    case 'p':       // "ap" = a paragraph
      flag = current_par(cap->oap, cap->count1, include, 'p');
      break;
    case 's':       // "as" = a sentence
      flag = current_sent(cap->oap, cap->count1, include);
      break;
    case '"':       // "a"" = a double quoted string
    case '\'':       // "a'" = a single quoted string
    case '`':       // "a`" = a backtick quoted string
      flag = current_quote(cap->oap, cap->count1, include,
                           cap->nchar);
      break;
    default:
      flag = false;
      break;
    }
  
    curbuf->b_p_mps = mps_save;
    if (!flag) {
      clearopbeep(cap->oap);
    }
    adjust_cursor_col();
    curwin->w_set_curswant = true;
  }
  
  /*
   * "q" command: Start/stop recording.
   * "q:", "q/", "q?": edit command-line in command-line window.
   */
  static void nv_record(cmdarg_T *cap)
  {
    if (cap->oap->op_type == OP_FORMAT) {
      // "gqq" is the same as "gqgq": format line
      cap->cmdchar = 'g';
      cap->nchar = 'q';
      nv_operator(cap);
    } else if (!checkclearop(cap->oap)) {
      if (cap->nchar == ':' || cap->nchar == '/' || cap->nchar == '?') {
        stuffcharReadbuff(cap->nchar);
        stuffcharReadbuff(K_CMDWIN);
      } else {
        // (stop) recording into a named register, unless executing a
        // register.
        if (reg_executing == 0 && do_record(cap->nchar) == FAIL) {
          clearopbeep(cap->oap);
        }
      }
    }
  }
  
  /*
   * Handle the "@r" command.
   */
  static void nv_at(cmdarg_T *cap)
  {
    if (checkclearop(cap->oap)) {
      return;
    }
    if (cap->nchar == '=') {
      if (get_expr_register() == NUL) {
        return;
      }
    }
    while (cap->count1-- && !got_int) {
      if (do_execreg(cap->nchar, false, false, false) == false) {
        clearopbeep(cap->oap);
        break;
      }
      line_breakcheck();
    }
  }
  
  /*
   * Handle the CTRL-U and CTRL-D commands.
   */
  static void nv_halfpage(cmdarg_T *cap)
  {
    if ((cap->cmdchar == Ctrl_U && curwin->w_cursor.lnum == 1)
        || (cap->cmdchar == Ctrl_D
            && curwin->w_cursor.lnum == curbuf->b_ml.ml_line_count)) {
      clearopbeep(cap->oap);
    } else if (!checkclearop(cap->oap)) {
      halfpage(cap->cmdchar == Ctrl_D, cap->count0);
    }
  }
  
  /*
   * Handle "J" or "gJ" command.
   */
  static void nv_join(cmdarg_T *cap)
  {
    if (VIsual_active) {  // join the visual lines
      nv_operator(cap);
    } else if (!checkclearop(cap->oap)) {
      if (cap->count0 <= 1) {
        cap->count0 = 2;  // default for join is two lines!
      }
      if (curwin->w_cursor.lnum + cap->count0 - 1 >
          curbuf->b_ml.ml_line_count) {
        // can't join when on the last line
        if (cap->count0 <= 2) {
          clearopbeep(cap->oap);
          return;
        }
        cap->count0 = curbuf->b_ml.ml_line_count - curwin->w_cursor.lnum + 1;
      }
  
      prep_redo(cap->oap->regname, cap->count0,
                NUL, cap->cmdchar, NUL, NUL, cap->nchar);
      do_join((size_t)cap->count0, cap->nchar == NUL, true, true, true);
    }
  }
  
  /*
   * "P", "gP", "p" and "gp" commands.
   */
  static void nv_put(cmdarg_T *cap)
  {
    nv_put_opt(cap, false);
  }
  
  // "P", "gP", "p" and "gp" commands.
  // "fix_indent" is true for "[p", "[P", "]p" and "]P".
  static void nv_put_opt(cmdarg_T *cap, bool fix_indent)
  {
    int regname = 0;
    yankreg_T *savereg = NULL;
    bool empty = false;
    bool was_visual = false;
    int dir;
    int flags = 0;
  
    if (cap->oap->op_type != OP_NOP) {
      // "dp" is ":diffput"
      if (cap->oap->op_type == OP_DELETE && cap->cmdchar == 'p') {
        clearop(cap->oap);
        assert(cap->opcount >= 0);
        nv_diffgetput(true, (size_t)cap->opcount);
      } else {
        clearopbeep(cap->oap);
      }
    } else if (bt_prompt(curbuf) && !prompt_curpos_editable()) {
      clearopbeep(cap->oap);
    } else {
      if (fix_indent) {
        dir = (cap->cmdchar == ']' && cap->nchar == 'p')
          ? FORWARD : BACKWARD;
        flags |= PUT_FIXINDENT;
      } else {
        dir = (cap->cmdchar == 'P'
               || ((cap->cmdchar == 'g' || cap->cmdchar == 'z')
                   && cap->nchar == 'P')) ? BACKWARD : FORWARD;
      }
      prep_redo_cmd(cap);
      if (cap->cmdchar == 'g') {
        flags |= PUT_CURSEND;
      } else if (cap->cmdchar == 'z') {
        flags |= PUT_BLOCK_INNER;
      }
  
      if (VIsual_active) {
        // Putting in Visual mode: The put text replaces the selected
        // text.  First delete the selected text, then put the new text.
        // Need to save and restore the registers that the delete
        // overwrites if the old contents is being put.
        was_visual = true;
        regname = cap->oap->regname;
        // '+' and '*' could be the same selection
        bool clipoverwrite = (regname == '+' || regname == '*')
                             && (cb_flags & CB_UNNAMEDMASK);
        if (regname == 0 || regname == '"' || clipoverwrite
            || ascii_isdigit(regname) || regname == '-') {
          // The delete might overwrite the register we want to put, save it first
          savereg = copy_register(regname);
        }
  
        // To place the cursor correctly after a blockwise put, and to leave the
        // text in the correct position when putting over a selection with
        // 'virtualedit' and past the end of the line, we use the 'c' operator in
        // do_put(), which requires the visual selection to still be active.
        if (!VIsual_active || VIsual_mode == 'V' || regname != '.') {
          // Now delete the selected text. Avoid messages here.
          cap->cmdchar = 'd';
          cap->nchar = NUL;
          cap->oap->regname = NUL;
          msg_silent++;
          nv_operator(cap);
          do_pending_operator(cap, 0, false);
          empty = (curbuf->b_ml.ml_flags & ML_EMPTY);
          msg_silent--;
  
          // delete PUT_LINE_BACKWARD;
          cap->oap->regname = regname;
        }
  
        // When deleted a linewise Visual area, put the register as
        // lines to avoid it joined with the next line.  When deletion was
        // charwise, split a line when putting lines.
        if (VIsual_mode == 'V') {
          flags |= PUT_LINE;
        } else if (VIsual_mode == 'v') {
          flags |= PUT_LINE_SPLIT;
        }
        if (VIsual_mode == Ctrl_V && dir == FORWARD) {
          flags |= PUT_LINE_FORWARD;
        }
        dir = BACKWARD;
        if ((VIsual_mode != 'V'
             && curwin->w_cursor.col < curbuf->b_op_start.col)
            || (VIsual_mode == 'V'
                && curwin->w_cursor.lnum < curbuf->b_op_start.lnum)) {
          // cursor is at the end of the line or end of file, put
          // forward.
          dir = FORWARD;
        }
        // May have been reset in do_put().
        VIsual_active = true;
      }
      do_put(cap->oap->regname, savereg, dir, cap->count1, flags);
  
      // If a register was saved, free it
      if (savereg != NULL) {
        free_register(savereg);
        xfree(savereg);
      }
  
      // What to reselect with "gv"?  Selecting the just put text seems to
      // be the most useful, since the original text was removed.
      if (was_visual) {
        curbuf->b_visual.vi_start = curbuf->b_op_start;
        curbuf->b_visual.vi_end = curbuf->b_op_end;
        // need to adjust cursor position
        if (*p_sel == 'e') {
          inc(&curbuf->b_visual.vi_end);
        }
      }
  
      // When all lines were selected and deleted do_put() leaves an empty
      // line that needs to be deleted now.
      if (empty && *ml_get(curbuf->b_ml.ml_line_count) == NUL) {
        ml_delete(curbuf->b_ml.ml_line_count, true);
        deleted_lines(curbuf->b_ml.ml_line_count + 1, 1);
  
        // If the cursor was in that line, move it to the end of the last
        // line.
        if (curwin->w_cursor.lnum > curbuf->b_ml.ml_line_count) {
          curwin->w_cursor.lnum = curbuf->b_ml.ml_line_count;
          coladvance(MAXCOL);
        }
      }
      auto_format(false, true);
    }
  }
  
  /*
   * "o" and "O" commands.
   */
  static void nv_open(cmdarg_T *cap)
  {
    // "do" is ":diffget"
    if (cap->oap->op_type == OP_DELETE && cap->cmdchar == 'o') {
      clearop(cap->oap);
      assert(cap->opcount >= 0);
      nv_diffgetput(false, (size_t)cap->opcount);
    } else if (VIsual_active) {
      // switch start and end of visual/
      v_swap_corners(cap->cmdchar);
    } else if (bt_prompt(curbuf)) {
      clearopbeep(cap->oap);
    } else {
      n_opencmd(cap);
    }
  }
  
  /// Calculate start/end virtual columns for operating in block mode.
  ///
  /// @param initial  when true: adjust position for 'selectmode'
  static void get_op_vcol(oparg_T *oap, colnr_T redo_VIsual_vcol, bool initial)
  {
    colnr_T start;
    colnr_T end;
  
    if (VIsual_mode != Ctrl_V
        || (!initial && oap->end.col < curwin->w_width_inner)) {
      return;
    }
  
    oap->motion_type = kMTBlockWise;
  
    // prevent from moving onto a trail byte
    mark_mb_adjustpos(curwin->w_buffer, &oap->end);
  
    getvvcol(curwin, &(oap->start), &oap->start_vcol, NULL, &oap->end_vcol);
    if (!redo_VIsual_busy) {
      getvvcol(curwin, &(oap->end), &start, NULL, &end);
  
      if (start < oap->start_vcol) {
        oap->start_vcol = start;
      }
      if (end > oap->end_vcol) {
        if (initial && *p_sel == 'e'
            && start >= 1
            && start - 1 >= oap->end_vcol) {
          oap->end_vcol = start - 1;
        } else {
          oap->end_vcol = end;
        }
      }
    }
  
    // if '$' was used, get oap->end_vcol from longest line
    if (curwin->w_curswant == MAXCOL) {
      curwin->w_cursor.col = MAXCOL;
      oap->end_vcol = 0;
      for (curwin->w_cursor.lnum = oap->start.lnum;
           curwin->w_cursor.lnum <= oap->end.lnum; ++curwin->w_cursor.lnum) {
        getvvcol(curwin, &curwin->w_cursor, NULL, NULL, &end);
        if (end > oap->end_vcol) {
          oap->end_vcol = end;
        }
      }
    } else if (redo_VIsual_busy) {
      oap->end_vcol = oap->start_vcol + redo_VIsual_vcol - 1;
    }
  
    // Correct oap->end.col and oap->start.col to be the
    // upper-left and lower-right corner of the block area.
    //
    // (Actually, this does convert column positions into character
    // positions)
    curwin->w_cursor.lnum = oap->end.lnum;
    coladvance(oap->end_vcol);
    oap->end = curwin->w_cursor;
  
    curwin->w_cursor = oap->start;
    coladvance(oap->start_vcol);
    oap->start = curwin->w_cursor;
  }
  
  // Handle an arbitrary event in normal mode
  static void nv_event(cmdarg_T *cap)
  {
    // Garbage collection should have been executed before blocking for events in
    // the `os_inchar` in `state_enter`, but we also disable it here in case the
    // `os_inchar` branch was not executed (!multiqueue_empty(loop.events), which
    // could have `may_garbage_collect` set to true in `normal_check`).
    //
    // That is because here we may run code that calls `os_inchar`
    // later(`f_confirm` or `get_keystroke` for example), but in these cases it is
    // not safe to perform garbage collection because there could be unreferenced
    // lists or dicts being used.
    may_garbage_collect = false;
    bool may_restart = (restart_edit != 0 || restart_VIsual_select != 0);
    state_handle_k_event();
    finish_op = false;
    if (may_restart) {
      // Tricky: if restart_edit was set before the handler we are in ctrl-o mode,
      // but if not, the event should be allowed to trigger :startinsert.
      cap->retval |= CA_COMMAND_BUSY;  // don't call edit() or restart Select now
    }
  }
  
  /// @return true when 'mousemodel' is set to "popup" or "popup_setpos".
  static bool mouse_model_popup(void)
  {
    return p_mousem[0] == 'p';
  }
  
  void normal_cmd(oparg_T *oap, bool toplevel)
  {
    NormalState s;
    normal_state_init(&s);
    s.toplevel = toplevel;
    s.oa = *oap;
    normal_prepare(&s);
    (void)normal_execute(&s.state, safe_vgetc());
    *oap = s.oa;
  }
  