text: /* vi:set ts=8 sts=4 sw=4:
   *
   * VIM - Vi IMproved	by Bram Moolenaar
   *
   * Do ":help uganda"  in Vim to read a list of people who contributed.
   * Do ":help credits" in Vim to see a list of people who contributed.
   * See README.txt for an overview of the Vim source code.
   */
  
  #include "vim.h"
  
  static int path_is_url __ARGS((char_u *p));
  #if defined(FEAT_WINDOWS) || defined(PROTO)
  static void win_init __ARGS((win_T *newp, win_T *oldp, int flags));
  static void win_init_some __ARGS((win_T *newp, win_T *oldp));
  static void frame_comp_pos __ARGS((frame_T *topfrp, int *row, int *col));
  static void frame_setheight __ARGS((frame_T *curfrp, int height));
  #ifdef FEAT_VERTSPLIT
  static void frame_setwidth __ARGS((frame_T *curfrp, int width));
  #endif
  static void win_exchange __ARGS((long));
  static void win_rotate __ARGS((int, int));
  static void win_totop __ARGS((int size, int flags));
  static void win_equal_rec __ARGS((win_T *next_curwin, int current, frame_T *topfr, int dir, int col, int row, int width, int height));
  static int last_window __ARGS((void));
  static int close_last_window_tabpage __ARGS((win_T *win, int free_buf, tabpage_T *prev_curtab));
  static win_T *win_free_mem __ARGS((win_T *win, int *dirp, tabpage_T *tp));
  static frame_T *win_altframe __ARGS((win_T *win, tabpage_T *tp));
  static tabpage_T *alt_tabpage __ARGS((void));
  static win_T *frame2win __ARGS((frame_T *frp));
  static int frame_has_win __ARGS((frame_T *frp, win_T *wp));
  static void frame_new_height __ARGS((frame_T *topfrp, int height, int topfirst, int wfh));
  static int frame_fixed_height __ARGS((frame_T *frp));
  #ifdef FEAT_VERTSPLIT
  static int frame_fixed_width __ARGS((frame_T *frp));
  static void frame_add_statusline __ARGS((frame_T *frp));
  static void frame_new_width __ARGS((frame_T *topfrp, int width, int leftfirst, int wfw));
  static void frame_add_vsep __ARGS((frame_T *frp));
  static int frame_minwidth __ARGS((frame_T *topfrp, win_T *next_curwin));
  static void frame_fix_width __ARGS((win_T *wp));
  #endif
  #endif
  static int win_alloc_firstwin __ARGS((win_T *oldwin));
  static void new_frame __ARGS((win_T *wp));
  #if defined(FEAT_WINDOWS) || defined(PROTO)
  static tabpage_T *alloc_tabpage __ARGS((void));
  static int leave_tabpage __ARGS((buf_T *new_curbuf, int trigger_leave_autocmds));
  static void enter_tabpage __ARGS((tabpage_T *tp, buf_T *old_curbuf, int trigger_enter_autocmds, int trigger_leave_autocmds));
  static void frame_fix_height __ARGS((win_T *wp));
  static int frame_minheight __ARGS((frame_T *topfrp, win_T *next_curwin));
  static void win_enter_ext __ARGS((win_T *wp, int undo_sync, int no_curwin, int trigger_enter_autocmds, int trigger_leave_autocmds));
  static void win_free __ARGS((win_T *wp, tabpage_T *tp));
  static void frame_append __ARGS((frame_T *after, frame_T *frp));
  static void frame_insert __ARGS((frame_T *before, frame_T *frp));
  static void frame_remove __ARGS((frame_T *frp));
  # ifdef FEAT_VERTSPLIT
  static void win_goto_ver __ARGS((int up, long count));
  static void win_goto_hor __ARGS((int left, long count));
  # endif
  static void frame_add_height __ARGS((frame_T *frp, int n));
  static void last_status_rec __ARGS((frame_T *fr, int statusline));
  
  static void make_snapshot_rec __ARGS((frame_T *fr, frame_T **frp));
  static void clear_snapshot __ARGS((tabpage_T *tp, int idx));
  static void clear_snapshot_rec __ARGS((frame_T *fr));
  static int check_snapshot_rec __ARGS((frame_T *sn, frame_T *fr));
  static win_T *restore_snapshot_rec __ARGS((frame_T *sn, frame_T *fr));
  
  static int frame_check_height __ARGS((frame_T *topfrp, int height));
  #ifdef FEAT_VERTSPLIT
  static int frame_check_width __ARGS((frame_T *topfrp, int width));
  #endif
  
  #endif /* FEAT_WINDOWS */
  
  static win_T *win_alloc __ARGS((win_T *after, int hidden));
  static void set_fraction __ARGS((win_T *wp));
  
  #define URL_SLASH	1		/* path_is_url() has found "://" */
  #define URL_BACKSLASH	2		/* path_is_url() has found ":\\" */
  
  #define NOWIN		(win_T *)-1	/* non-existing window */
  
  #ifdef FEAT_WINDOWS
  # define ROWS_AVAIL (Rows - p_ch - tabline_height())
  #else
  # define ROWS_AVAIL (Rows - p_ch)
  #endif
  
  #if defined(FEAT_WINDOWS) || defined(PROTO)
  
  static char *m_onlyone = N_("Already only one window");
  
  /*
   * all CTRL-W window commands are handled here, called from normal_cmd().
   */
      void
  do_window(nchar, Prenum, xchar)
      int		nchar;
      long	Prenum;
      int		xchar;	    /* extra char from ":wincmd gx" or NUL */
  {
      long	Prenum1;
      win_T	*wp;
  #if defined(FEAT_SEARCHPATH) || defined(FEAT_FIND_ID)
      char_u	*ptr;
      linenr_T    lnum = -1;
  #endif
  #ifdef FEAT_FIND_ID
      int		type = FIND_DEFINE;
      int		len;
  #endif
      char_u	cbuf[40];
  
      if (Prenum == 0)
  	Prenum1 = 1;
      else
  	Prenum1 = Prenum;
  
  #ifdef FEAT_CMDWIN
  # define CHECK_CMDWIN if (cmdwin_type != 0) { EMSG(_(e_cmdwin)); break; }
  #else
  # define CHECK_CMDWIN
  #endif
  
      switch (nchar)
      {
  /* split current window in two parts, horizontally */
      case 'S':
      case Ctrl_S:
      case 's':
  		CHECK_CMDWIN
  #ifdef FEAT_VISUAL
  		reset_VIsual_and_resel();	/* stop Visual mode */
  #endif
  #ifdef FEAT_QUICKFIX
  		/* When splitting the quickfix window open a new buffer in it,
  		 * don't replicate the quickfix buffer. */
  		if (bt_quickfix(curbuf))
  		    goto newwindow;
  #endif
  #ifdef FEAT_GUI
  		need_mouse_correct = TRUE;
  #endif
  		win_split((int)Prenum, 0);
  		break;
  
  #ifdef FEAT_VERTSPLIT
  /* split current window in two parts, vertically */
      case Ctrl_V:
      case 'v':
  		CHECK_CMDWIN
  # ifdef FEAT_VISUAL
  		reset_VIsual_and_resel();	/* stop Visual mode */
  # endif
  # ifdef FEAT_QUICKFIX
  		/* When splitting the quickfix window open a new buffer in it,
  		 * don't replicate the quickfix buffer. */
  		if (bt_quickfix(curbuf))
  		    goto newwindow;
  # endif
  # ifdef FEAT_GUI
  		need_mouse_correct = TRUE;
  # endif
  		win_split((int)Prenum, WSP_VERT);
  		break;
  #endif
  
  /* split current window and edit alternate file */
      case Ctrl_HAT:
      case '^':
  		CHECK_CMDWIN
  #ifdef FEAT_VISUAL
  		reset_VIsual_and_resel();	/* stop Visual mode */
  #endif
  		STRCPY(cbuf, "split #");
  		if (Prenum)
  		    vim_snprintf((char *)cbuf + 7, sizeof(cbuf) - 7,
  							       "%ld", Prenum);
  		do_cmdline_cmd(cbuf);
  		break;
  
  /* open new window */
      case Ctrl_N:
      case 'n':
  		CHECK_CMDWIN
  #ifdef FEAT_VISUAL
  		reset_VIsual_and_resel();	/* stop Visual mode */
  #endif
  #ifdef FEAT_QUICKFIX
  newwindow:
  #endif
  		if (Prenum)
  		    /* window height */
  		    vim_snprintf((char *)cbuf, sizeof(cbuf) - 5, "%ld", Prenum);
  		else
  		    cbuf[0] = NUL;
  #if defined(FEAT_VERTSPLIT) && defined(FEAT_QUICKFIX)
  		if (nchar == 'v' || nchar == Ctrl_V)
  		    STRCAT(cbuf, "v");
  #endif
  		STRCAT(cbuf, "new");
  		do_cmdline_cmd(cbuf);
  		break;
  
  /* quit current window */
      case Ctrl_Q:
      case 'q':
  #ifdef FEAT_VISUAL
  		reset_VIsual_and_resel();	/* stop Visual mode */
  #endif
  		do_cmdline_cmd((char_u *)"quit");
  		break;
  
  /* close current window */
      case Ctrl_C:
      case 'c':
  #ifdef FEAT_VISUAL
  		reset_VIsual_and_resel();	/* stop Visual mode */
  #endif
  		do_cmdline_cmd((char_u *)"close");
  		break;
  
  #if defined(FEAT_WINDOWS) && defined(FEAT_QUICKFIX)
  /* close preview window */
      case Ctrl_Z:
      case 'z':
  		CHECK_CMDWIN
  #ifdef FEAT_VISUAL
  		reset_VIsual_and_resel();	/* stop Visual mode */
  #endif
  		do_cmdline_cmd((char_u *)"pclose");
  		break;
  
  /* cursor to preview window */
      case 'P':
  		for (wp = firstwin; wp != NULL; wp = wp->w_next)
  		    if (wp->w_p_pvw)
  			break;
  		if (wp == NULL)
  		    EMSG(_("E441: There is no preview window"));
  		else
  		    win_goto(wp);
  		break;
  #endif
  
  /* close all but current window */
      case Ctrl_O:
      case 'o':
  		CHECK_CMDWIN
  #ifdef FEAT_VISUAL
  		reset_VIsual_and_resel();	/* stop Visual mode */
  #endif
  		do_cmdline_cmd((char_u *)"only");
  		break;
  
  /* cursor to next window with wrap around */
      case Ctrl_W:
      case 'w':
  /* cursor to previous window with wrap around */
      case 'W':
  		CHECK_CMDWIN
  		if (firstwin == lastwin && Prenum != 1)	/* just one window */
  		    beep_flush();
  		else
  		{
  		    if (Prenum)			/* go to specified window */
  		    {
  			for (wp = firstwin; --Prenum > 0; )
  			{
  			    if (wp->w_next == NULL)
  				break;
  			    else
  				wp = wp->w_next;
  			}
  		    }
  		    else
  		    {
  			if (nchar == 'W')	    /* go to previous window */
  			{
  			    wp = curwin->w_prev;
  			    if (wp == NULL)
  				wp = lastwin;	    /* wrap around */
  			}
  			else			    /* go to next window */
  			{
  			    wp = curwin->w_next;
  			    if (wp == NULL)
  				wp = firstwin;	    /* wrap around */
  			}
  		    }
  		    win_goto(wp);
  		}
  		break;
  
  /* cursor to window below */
      case 'j':
      case K_DOWN:
      case Ctrl_J:
  		CHECK_CMDWIN
  #ifdef FEAT_VERTSPLIT
  		win_goto_ver(FALSE, Prenum1);
  #else
  		for (wp = curwin; wp->w_next != NULL && Prenum1-- > 0;
  							    wp = wp->w_next)
  		    ;
  		win_goto(wp);
  #endif
  		break;
  
  /* cursor to window above */
      case 'k':
      case K_UP:
      case Ctrl_K:
  		CHECK_CMDWIN
  #ifdef FEAT_VERTSPLIT
  		win_goto_ver(TRUE, Prenum1);
  #else
  		for (wp = curwin; wp->w_prev != NULL && Prenum1-- > 0;
  							    wp = wp->w_prev)
  		    ;
  		win_goto(wp);
  #endif
  		break;
  
  #ifdef FEAT_VERTSPLIT
  /* cursor to left window */
      case 'h':
      case K_LEFT:
      case Ctrl_H:
      case K_BS:
  		CHECK_CMDWIN
  		win_goto_hor(TRUE, Prenum1);
  		break;
  
  /* cursor to right window */
      case 'l':
      case K_RIGHT:
      case Ctrl_L:
  		CHECK_CMDWIN
  		win_goto_hor(FALSE, Prenum1);
  		break;
  #endif
  
  /* move window to new tab page */
      case 'T':
  		if (one_window())
  		    MSG(_(m_onlyone));
  		else
  		{
  		    tabpage_T	*oldtab = curtab;
  		    tabpage_T	*newtab;
  
  		    /* First create a new tab with the window, then go back to
  		     * the old tab and close the window there. */
  		    wp = curwin;
  		    if (win_new_tabpage((int)Prenum) == OK
  						     && valid_tabpage(oldtab))
  		    {
  			newtab = curtab;
  			goto_tabpage_tp(oldtab, TRUE, TRUE);
  			if (curwin == wp)
  			    win_close(curwin, FALSE);
  			if (valid_tabpage(newtab))
  			    goto_tabpage_tp(newtab, TRUE, TRUE);
  		    }
  		}
  		break;
  
  /* cursor to top-left window */
      case 't':
      case Ctrl_T:
  		win_goto(firstwin);
  		break;
  
  /* cursor to bottom-right window */
      case 'b':
      case Ctrl_B:
  		win_goto(lastwin);
  		break;
  
  /* cursor to last accessed (previous) window */
      case 'p':
      case Ctrl_P:
  		if (prevwin == NULL)
  		    beep_flush();
  		else
  		    win_goto(prevwin);
  		break;
  
  /* exchange current and next window */
      case 'x':
      case Ctrl_X:
  		CHECK_CMDWIN
  		win_exchange(Prenum);
  		break;
  
  /* rotate windows downwards */
      case Ctrl_R:
      case 'r':
  		CHECK_CMDWIN
  #ifdef FEAT_VISUAL
  		reset_VIsual_and_resel();	/* stop Visual mode */
  #endif
  		win_rotate(FALSE, (int)Prenum1);    /* downwards */
  		break;
  
  /* rotate windows upwards */
      case 'R':
  		CHECK_CMDWIN
  #ifdef FEAT_VISUAL
  		reset_VIsual_and_resel();	/* stop Visual mode */
  #endif
  		win_rotate(TRUE, (int)Prenum1);	    /* upwards */
  		break;
  
  /* move window to the very top/bottom/left/right */
      case 'K':
      case 'J':
  #ifdef FEAT_VERTSPLIT
      case 'H':
      case 'L':
  #endif
  		CHECK_CMDWIN
  		win_totop((int)Prenum,
  			((nchar == 'H' || nchar == 'L') ? WSP_VERT : 0)
  			| ((nchar == 'H' || nchar == 'K') ? WSP_TOP : WSP_BOT));
  		break;
  
  /* make all windows the same height */
      case '=':
  #ifdef FEAT_GUI
  		need_mouse_correct = TRUE;
  #endif
  		win_equal(NULL, FALSE, 'b');
  		break;
  
  /* increase current window height */
      case '+':
  #ifdef FEAT_GUI
  		need_mouse_correct = TRUE;
  #endif
  		win_setheight(curwin->w_height + (int)Prenum1);
  		break;
  
  /* decrease current window height */
      case '-':
  #ifdef FEAT_GUI
  		need_mouse_correct = TRUE;
  #endif
  		win_setheight(curwin->w_height - (int)Prenum1);
  		break;
  
  /* set current window height */
      case Ctrl__:
      case '_':
  #ifdef FEAT_GUI
  		need_mouse_correct = TRUE;
  #endif
  		win_setheight(Prenum ? (int)Prenum : 9999);
  		break;
  
  #ifdef FEAT_VERTSPLIT
  /* increase current window width */
      case '>':
  #ifdef FEAT_GUI
  		need_mouse_correct = TRUE;
  #endif
  		win_setwidth(curwin->w_width + (int)Prenum1);
  		break;
  
  /* decrease current window width */
      case '<':
  #ifdef FEAT_GUI
  		need_mouse_correct = TRUE;
  #endif
  		win_setwidth(curwin->w_width - (int)Prenum1);
  		break;
  
  /* set current window width */
      case '|':
  #ifdef FEAT_GUI
  		need_mouse_correct = TRUE;
  #endif
  		win_setwidth(Prenum != 0 ? (int)Prenum : 9999);
  		break;
  #endif
  
  /* jump to tag and split window if tag exists (in preview window) */
  #if defined(FEAT_QUICKFIX)
      case '}':
  		CHECK_CMDWIN
  		if (Prenum)
  		    g_do_tagpreview = Prenum;
  		else
  		    g_do_tagpreview = p_pvh;
  		/*FALLTHROUGH*/
  #endif
      case ']':
      case Ctrl_RSB:
  		CHECK_CMDWIN
  #ifdef FEAT_VISUAL
  		reset_VIsual_and_resel();	/* stop Visual mode */
  #endif
  		if (Prenum)
  		    postponed_split = Prenum;
  		else
  		    postponed_split = -1;
  
  		/* Execute the command right here, required when
  		 * "wincmd ]" was used in a function. */
  		do_nv_ident(Ctrl_RSB, NUL);
  		break;
  
  #ifdef FEAT_SEARCHPATH
  /* edit file name under cursor in a new window */
      case 'f':
      case 'F':
      case Ctrl_F:
  wingotofile:
  		CHECK_CMDWIN
  
  		ptr = grab_file_name(Prenum1, &lnum);
  		if (ptr != NULL)
  		{
  # ifdef FEAT_GUI
  		    need_mouse_correct = TRUE;
  # endif
  		    setpcmark();
  		    if (win_split(0, 0) == OK)
  		    {
  			RESET_BINDING(curwin);
  			(void)do_ecmd(0, ptr, NULL, NULL, ECMD_LASTL,
  							   ECMD_HIDE, NULL);
  			if (nchar == 'F' && lnum >= 0)
  			{
  			    curwin->w_cursor.lnum = lnum;
  			    check_cursor_lnum();
  			    beginline(BL_SOL | BL_FIX);
  			}
  		    }
  		    vim_free(ptr);
  		}
  		break;
  #endif
  
  #ifdef FEAT_FIND_ID
  /* Go to the first occurrence of the identifier under cursor along path in a
   * new window -- webb
   */
      case 'i':			    /* Go to any match */
      case Ctrl_I:
  		type = FIND_ANY;
  		/* FALLTHROUGH */
      case 'd':			    /* Go to definition, using 'define' */
      case Ctrl_D:
  		CHECK_CMDWIN
  		if ((len = find_ident_under_cursor(&ptr, FIND_IDENT)) == 0)
  		    break;
  		find_pattern_in_path(ptr, 0, len, TRUE,
  			Prenum == 0 ? TRUE : FALSE, type,
  			Prenum1, ACTION_SPLIT, (linenr_T)1, (linenr_T)MAXLNUM);
  		curwin->w_set_curswant = TRUE;
  		break;
  #endif
  
      case K_KENTER:
      case CAR:
  #if defined(FEAT_QUICKFIX)
  		/*
  		 * In a quickfix window a <CR> jumps to the error under the
  		 * cursor in a new window.
  		 */
  		if (bt_quickfix(curbuf))
  		{
  		    sprintf((char *)cbuf, "split +%ld%s",
  				(long)curwin->w_cursor.lnum,
  				(curwin->w_llist_ref == NULL) ? "cc" : "ll");
  		    do_cmdline_cmd(cbuf);
  		}
  #endif
  		break;
  
  
  /* CTRL-W g  extended commands */
      case 'g':
      case Ctrl_G:
  		CHECK_CMDWIN
  #ifdef USE_ON_FLY_SCROLL
  		dont_scroll = TRUE;		/* disallow scrolling here */
  #endif
  		++no_mapping;
  		++allow_keys;   /* no mapping for xchar, but allow key codes */
  		if (xchar == NUL)
  		    xchar = plain_vgetc();
  		LANGMAP_ADJUST(xchar, TRUE);
  		--no_mapping;
  		--allow_keys;
  #ifdef FEAT_CMDL_INFO
  		(void)add_to_showcmd(xchar);
  #endif
  		switch (xchar)
  		{
  #if defined(FEAT_QUICKFIX)
  		    case '}':
  			xchar = Ctrl_RSB;
  			if (Prenum)
  			    g_do_tagpreview = Prenum;
  			else
  			    g_do_tagpreview = p_pvh;
  			/*FALLTHROUGH*/
  #endif
  		    case ']':
  		    case Ctrl_RSB:
  #ifdef FEAT_VISUAL
  			reset_VIsual_and_resel();	/* stop Visual mode */
  #endif
  			if (Prenum)
  			    postponed_split = Prenum;
  			else
  			    postponed_split = -1;
  
  			/* Execute the command right here, required when
  			 * "wincmd g}" was used in a function. */
  			do_nv_ident('g', xchar);
  			break;
  
  #ifdef FEAT_SEARCHPATH
  		    case 'f':	    /* CTRL-W gf: "gf" in a new tab page */
  		    case 'F':	    /* CTRL-W gF: "gF" in a new tab page */
  			cmdmod.tab = tabpage_index(curtab) + 1;
  			nchar = xchar;
  			goto wingotofile;
  #endif
  		    default:
  			beep_flush();
  			break;
  		}
  		break;
  
      default:	beep_flush();
  		break;
      }
  }
  
  /*
   * split the current window, implements CTRL-W s and :split
   *
   * "size" is the height or width for the new window, 0 to use half of current
   * height or width.
   *
   * "flags":
   * WSP_ROOM: require enough room for new window
   * WSP_VERT: vertical split.
   * WSP_TOP:  open window at the top-left of the shell (help window).
   * WSP_BOT:  open window at the bottom-right of the shell (quickfix window).
   * WSP_HELP: creating the help window, keep layout snapshot
   *
   * return FAIL for failure, OK otherwise
   */
      int
  win_split(size, flags)
      int		size;
      int		flags;
  {
      /* When the ":tab" modifier was used open a new tab page instead. */
      if (may_open_tabpage() == OK)
  	return OK;
  
      /* Add flags from ":vertical", ":topleft" and ":botright". */
      flags |= cmdmod.split;
      if ((flags & WSP_TOP) && (flags & WSP_BOT))
      {
  	EMSG(_("E442: Can't split topleft and botright at the same time"));
  	return FAIL;
      }
  
      /* When creating the help window make a snapshot of the window layout.
       * Otherwise clear the snapshot, it's now invalid. */
      if (flags & WSP_HELP)
  	make_snapshot(SNAP_HELP_IDX);
      else
  	clear_snapshot(curtab, SNAP_HELP_IDX);
  
      return win_split_ins(size, flags, NULL, 0);
  }
  
  /*
   * When "new_wp" is NULL: split the current window in two.
   * When "new_wp" is not NULL: insert this window at the far
   * top/left/right/bottom.
   * return FAIL for failure, OK otherwise
   */
      int
  win_split_ins(size, flags, new_wp, dir)
      int		size;
      int		flags;
      win_T	*new_wp;
      int		dir;
  {
      win_T	*wp = new_wp;
      win_T	*oldwin;
      int		new_size = size;
      int		i;
      int		need_status = 0;
      int		do_equal = FALSE;
      int		needed;
      int		available;
      int		oldwin_height = 0;
      int		layout;
      frame_T	*frp, *curfrp;
      int		before;
  
      if (flags & WSP_TOP)
  	oldwin = firstwin;
      else if (flags & WSP_BOT)
  	oldwin = lastwin;
      else
  	oldwin = curwin;
  
      /* add a status line when p_ls == 1 and splitting the first window */
      if (lastwin == firstwin && p_ls == 1 && oldwin->w_status_height == 0)
      {
  	if (oldwin->w_height <= p_wmh && new_wp == NULL)
  	{
  	    EMSG(_(e_noroom));
  	    return FAIL;
  	}
  	need_status = STATUS_HEIGHT;
      }
  
  #ifdef FEAT_GUI
      /* May be needed for the scrollbars that are going to change. */
      if (gui.in_use)
  	out_flush();
  #endif
  
  #ifdef FEAT_VERTSPLIT
      if (flags & WSP_VERT)
      {
  	layout = FR_ROW;
  
  	/*
  	 * Check if we are able to split the current window and compute its
  	 * width.
  	 */
  	needed = p_wmw + 1;
  	if (flags & WSP_ROOM)
  	    needed += p_wiw - p_wmw;
  	if (p_ea || (flags & (WSP_BOT | WSP_TOP)))
  	{
  	    available = topframe->fr_width;
  	    needed += frame_minwidth(topframe, NULL);
  	}
  	else
  	    available = oldwin->w_width;
  	if (available < needed && new_wp == NULL)
  	{
  	    EMSG(_(e_noroom));
  	    return FAIL;
  	}
  	if (new_size == 0)
  	    new_size = oldwin->w_width / 2;
  	if (new_size > oldwin->w_width - p_wmw - 1)
  	    new_size = oldwin->w_width - p_wmw - 1;
  	if (new_size < p_wmw)
  	    new_size = p_wmw;
  
  	/* if it doesn't fit in the current window, need win_equal() */
  	if (oldwin->w_width - new_size - 1 < p_wmw)
  	    do_equal = TRUE;
  
  	/* We don't like to take lines for the new window from a
  	 * 'winfixwidth' window.  Take them from a window to the left or right
  	 * instead, if possible. */
  	if (oldwin->w_p_wfw)
  	    win_setwidth_win(oldwin->w_width + new_size, oldwin);
  
  	/* Only make all windows the same width if one of them (except oldwin)
  	 * is wider than one of the split windows. */
  	if (!do_equal && p_ea && size == 0 && *p_ead != 'v'
  	   && oldwin->w_frame->fr_parent != NULL)
  	{
  	    frp = oldwin->w_frame->fr_parent->fr_child;
  	    while (frp != NULL)
  	    {
  		if (frp->fr_win != oldwin && frp->fr_win != NULL
  			&& (frp->fr_win->w_width > new_size
  			    || frp->fr_win->w_width > oldwin->w_width
  						   - new_size - STATUS_HEIGHT))
  		{
  		    do_equal = TRUE;
  		    break;
  		}
  		frp = frp->fr_next;
  	    }
  	}
      }
      else
  #endif
      {
  	layout = FR_COL;
  
  	/*
  	 * Check if we are able to split the current window and compute its
  	 * height.
  	 */
  	needed = p_wmh + STATUS_HEIGHT + need_status;
  	if (flags & WSP_ROOM)
  	    needed += p_wh - p_wmh;
  	if (p_ea || (flags & (WSP_BOT | WSP_TOP)))
  	{
  	    available = topframe->fr_height;
  	    needed += frame_minheight(topframe, NULL);
  	}
  	else
  	{
  	    available = oldwin->w_height;
  	    needed += p_wmh;
  	}
  	if (available < needed && new_wp == NULL)
  	{
  	    EMSG(_(e_noroom));
  	    return FAIL;
  	}
  	oldwin_height = oldwin->w_height;
  	if (need_status)
  	{
  	    oldwin->w_status_height = STATUS_HEIGHT;
  	    oldwin_height -= STATUS_HEIGHT;
  	}
  	if (new_size == 0)
  	    new_size = oldwin_height / 2;
  
  	if (new_size > oldwin_height - p_wmh - STATUS_HEIGHT)
  	    new_size = oldwin_height - p_wmh - STATUS_HEIGHT;
  	if (new_size < p_wmh)
  	    new_size = p_wmh;
  
  	/* if it doesn't fit in the current window, need win_equal() */
  	if (oldwin_height - new_size - STATUS_HEIGHT < p_wmh)
  	    do_equal = TRUE;
  
  	/* We don't like to take lines for the new window from a
  	 * 'winfixheight' window.  Take them from a window above or below
  	 * instead, if possible. */
  	if (oldwin->w_p_wfh)
  	{
  	    win_setheight_win(oldwin->w_height + new_size + STATUS_HEIGHT,
  								      oldwin);
  	    oldwin_height = oldwin->w_height;
  	    if (need_status)
  		oldwin_height -= STATUS_HEIGHT;
  	}
  
  	/* Only make all windows the same height if one of them (except oldwin)
  	 * is higher than one of the split windows. */
  	if (!do_equal && p_ea && size == 0
  #ifdef FEAT_VERTSPLIT
  		&& *p_ead != 'h'
  #endif
  	   && oldwin->w_frame->fr_parent != NULL)
  	{
  	    frp = oldwin->w_frame->fr_parent->fr_child;
  	    while (frp != NULL)
  	    {
  		if (frp->fr_win != oldwin && frp->fr_win != NULL
  			&& (frp->fr_win->w_height > new_size
  			    || frp->fr_win->w_height > oldwin_height - new_size
  							      - STATUS_HEIGHT))
  		{
  		    do_equal = TRUE;
  		    break;
  		}
  		frp = frp->fr_next;
  	    }
  	}
      }
  
      /*
       * allocate new window structure and link it in the window list
       */
      if ((flags & WSP_TOP) == 0
  	    && ((flags & WSP_BOT)
  		|| (flags & WSP_BELOW)
  		|| (!(flags & WSP_ABOVE)
  		    && (
  #ifdef FEAT_VERTSPLIT
  			(flags & WSP_VERT) ? p_spr :
  #endif
  			p_sb))))
      {
  	/* new window below/right of current one */
  	if (new_wp == NULL)
  	    wp = win_alloc(oldwin, FALSE);
  	else
  	    win_append(oldwin, wp);
      }
      else
      {
  	if (new_wp == NULL)
  	    wp = win_alloc(oldwin->w_prev, FALSE);
  	else
  	    win_append(oldwin->w_prev, wp);
      }
  
      if (new_wp == NULL)
      {
  	if (wp == NULL)
  	    return FAIL;
  
  	new_frame(wp);
  	if (wp->w_frame == NULL)
  	{
  	    win_free(wp, NULL);
  	    return FAIL;
  	}
  
  	/* make the contents of the new window the same as the current one */
  	win_init(wp, curwin, flags);
      }
  
      /*
       * Reorganise the tree of frames to insert the new window.
       */
      if (flags & (WSP_TOP | WSP_BOT))
      {
  #ifdef FEAT_VERTSPLIT
  	if ((topframe->fr_layout == FR_COL && (flags & WSP_VERT) == 0)
  	    || (topframe->fr_layout == FR_ROW && (flags & WSP_VERT) != 0))
  #else
  	if (topframe->fr_layout == FR_COL)
  #endif
  	{
  	    curfrp = topframe->fr_child;
  	    if (flags & WSP_BOT)
  		while (curfrp->fr_next != NULL)
  		    curfrp = curfrp->fr_next;
  	}
  	else
  	    curfrp = topframe;
  	before = (flags & WSP_TOP);
      }
      else
      {
  	curfrp = oldwin->w_frame;
  	if (flags & WSP_BELOW)
  	    before = FALSE;
  	else if (flags & WSP_ABOVE)
  	    before = TRUE;
  	else
  #ifdef FEAT_VERTSPLIT
  	if (flags & WSP_VERT)
  	    before = !p_spr;
  	else
  #endif
  	    before = !p_sb;
      }
      if (curfrp->fr_parent == NULL || curfrp->fr_parent->fr_layout != layout)
      {
  	/* Need to create a new frame in the tree to make a branch. */
  	frp = (frame_T *)alloc_clear((unsigned)sizeof(frame_T));
  	*frp = *curfrp;
  	curfrp->fr_layout = layout;
  	frp->fr_parent = curfrp;
  	frp->fr_next = NULL;
  	frp->fr_prev = NULL;
  	curfrp->fr_child = frp;
  	curfrp->fr_win = NULL;
  	curfrp = frp;
  	if (frp->fr_win != NULL)
  	    oldwin->w_frame = frp;
  	else
  	    for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
  		frp->fr_parent = curfrp;
      }
  
      if (new_wp == NULL)
  	frp = wp->w_frame;
      else
  	frp = new_wp->w_frame;
      frp->fr_parent = curfrp->fr_parent;
  
      /* Insert the new frame at the right place in the frame list. */
      if (before)
  	frame_insert(curfrp, frp);
      else
  	frame_append(curfrp, frp);
  
      /* Set w_fraction now so that the cursor keeps the same relative
       * vertical position. */
      if (oldwin->w_height > 0)
  	set_fraction(oldwin);
      wp->w_fraction = oldwin->w_fraction;
  
  #ifdef FEAT_VERTSPLIT
      if (flags & WSP_VERT)
      {
  	wp->w_p_scr = curwin->w_p_scr;
  
  	if (need_status)
  	{
  	    win_new_height(oldwin, oldwin->w_height - 1);
  	    oldwin->w_status_height = need_status;
  	}
  	if (flags & (WSP_TOP | WSP_BOT))
  	{
  	    /* set height and row of new window to full height */
  	    wp->w_winrow = tabline_height();
  	    win_new_height(wp, curfrp->fr_height - (p_ls > 0));
  	    wp->w_status_height = (p_ls > 0);
  	}
  	else
  	{
  	    /* height and row of new window is same as current window */
  	    wp->w_winrow = oldwin->w_winrow;
  	    win_new_height(wp, oldwin->w_height);
  	    wp->w_status_height = oldwin->w_status_height;
  	}
  	frp->fr_height = curfrp->fr_height;
  
  	/* "new_size" of the current window goes to the new window, use
  	 * one column for the vertical separator */
  	win_new_width(wp, new_size);
  	if (before)
  	    wp->w_vsep_width = 1;
  	else
  	{
  	    wp->w_vsep_width = oldwin->w_vsep_width;
  	    oldwin->w_vsep_width = 1;
  	}
  	if (flags & (WSP_TOP | WSP_BOT))
  	{
  	    if (flags & WSP_BOT)
  		frame_add_vsep(curfrp);
  	    /* Set width of neighbor frame */
  	    frame_new_width(curfrp, curfrp->fr_width
  		     - (new_size + ((flags & WSP_TOP) != 0)), flags & WSP_TOP,
  								       FALSE);
  	}
  	else
  	    win_new_width(oldwin, oldwin->w_width - (new_size + 1));
  	if (before)	/* new window left of current one */
  	{
  	    wp->w_wincol = oldwin->w_wincol;
  	    oldwin->w_wincol += new_size + 1;
  	}
  	else		/* new window right of current one */
  	    wp->w_wincol = oldwin->w_wincol + oldwin->w_width + 1;
  	frame_fix_width(oldwin);
  	frame_fix_width(wp);
      }
      else
  #endif
      {
  	/* width and column of new window is same as current window */
  #ifdef FEAT_VERTSPLIT
  	if (flags & (WSP_TOP | WSP_BOT))
  	{
  	    wp->w_wincol = 0;
  	    win_new_width(wp, Columns);
  	    wp->w_vsep_width = 0;
  	}
  	else
  	{
  	    wp->w_wincol = oldwin->w_wincol;
  	    win_new_width(wp, oldwin->w_width);
  	    wp->w_vsep_width = oldwin->w_vsep_width;
  	}
  	frp->fr_width = curfrp->fr_width;
  #endif
  
  	/* "new_size" of the current window goes to the new window, use
  	 * one row for the status line */
  	win_new_height(wp, new_size);
  	if (flags & (WSP_TOP | WSP_BOT))
  	    frame_new_height(curfrp, curfrp->fr_height
  			- (new_size + STATUS_HEIGHT), flags & WSP_TOP, FALSE);
  	else
  	    win_new_height(oldwin, oldwin_height - (new_size + STATUS_HEIGHT));
  	if (before)	/* new window above current one */
  	{
  	    wp->w_winrow = oldwin->w_winrow;
  	    wp->w_status_height = STATUS_HEIGHT;
  	    oldwin->w_winrow += wp->w_height + STATUS_HEIGHT;
  	}
  	else		/* new window below current one */
  	{
  	    wp->w_winrow = oldwin->w_winrow + oldwin->w_height + STATUS_HEIGHT;
  	    wp->w_status_height = oldwin->w_status_height;
  	    oldwin->w_status_height = STATUS_HEIGHT;
  	}
  #ifdef FEAT_VERTSPLIT
  	if (flags & WSP_BOT)
  	    frame_add_statusline(curfrp);
  #endif
  	frame_fix_height(wp);
  	frame_fix_height(oldwin);
      }
  
      if (flags & (WSP_TOP | WSP_BOT))
  	(void)win_comp_pos();
  
      /*
       * Both windows need redrawing
       */
      redraw_win_later(wp, NOT_VALID);
      wp->w_redr_status = TRUE;
      redraw_win_later(oldwin, NOT_VALID);
      oldwin->w_redr_status = TRUE;
  
      if (need_status)
      {
  	msg_row = Rows - 1;
  	msg_col = sc_col;
  	msg_clr_eos_force();	/* Old command/ruler may still be there */
  	comp_col();
  	msg_row = Rows - 1;
  	msg_col = 0;	/* put position back at start of line */
      }
  
      /*
       * equalize the window sizes.
       */
      if (do_equal || dir != 0)
  	win_equal(wp, TRUE,
  #ifdef FEAT_VERTSPLIT
  		(flags & WSP_VERT) ? (dir == 'v' ? 'b' : 'h')
  		: dir == 'h' ? 'b' :
  #endif
  		'v');
  
      /* Don't change the window height/width to 'winheight' / 'winwidth' if a
       * size was given. */
  #ifdef FEAT_VERTSPLIT
      if (flags & WSP_VERT)
      {
  	i = p_wiw;
  	if (size != 0)
  	    p_wiw = size;
  
  # ifdef FEAT_GUI
  	/* When 'guioptions' includes 'L' or 'R' may have to add scrollbars. */
  	if (gui.in_use)
  	    gui_init_which_components(NULL);
  # endif
      }
      else
  #endif
      {
  	i = p_wh;
  	if (size != 0)
  	    p_wh = size;
      }
  
      /*
       * make the new window the current window
       */
      win_enter(wp, FALSE);
  #ifdef FEAT_VERTSPLIT
      if (flags & WSP_VERT)
  	p_wiw = i;
      else
  #endif
  	p_wh = i;
  
      return OK;
  }
  
  
  /*
   * Initialize window "newp" from window "oldp".
   * Used when splitting a window and when creating a new tab page.
   * The windows will both edit the same buffer.
   * WSP_NEWLOC may be specified in flags to prevent the location list from
   * being copied.
   */
      static void
  win_init(newp, oldp, flags)
      win_T	*newp;
      win_T	*oldp;
      int		 flags UNUSED;
  {
      int		i;
  
      newp->w_buffer = oldp->w_buffer;
  #ifdef FEAT_SYN_HL
      newp->w_s = &(oldp->w_buffer->b_s);
  #endif
      oldp->w_buffer->b_nwindows++;
      newp->w_cursor = oldp->w_cursor;
      newp->w_valid = 0;
      newp->w_curswant = oldp->w_curswant;
      newp->w_set_curswant = oldp->w_set_curswant;
      newp->w_topline = oldp->w_topline;
  #ifdef FEAT_DIFF
      newp->w_topfill = oldp->w_topfill;
  #endif
      newp->w_leftcol = oldp->w_leftcol;
      newp->w_pcmark = oldp->w_pcmark;
      newp->w_prev_pcmark = oldp->w_prev_pcmark;
      newp->w_alt_fnum = oldp->w_alt_fnum;
      newp->w_wrow = oldp->w_wrow;
      newp->w_fraction = oldp->w_fraction;
      newp->w_prev_fraction_row = oldp->w_prev_fraction_row;
  #ifdef FEAT_JUMPLIST
      copy_jumplist(oldp, newp);
  #endif
  #ifdef FEAT_QUICKFIX
      if (flags & WSP_NEWLOC)
      {
  	/* Don't copy the location list.  */
  	newp->w_llist = NULL;
  	newp->w_llist_ref = NULL;
      }
      else
  	copy_loclist(oldp, newp);
  #endif
      newp->w_localdir = (oldp->w_localdir == NULL)
  				    ? NULL : vim_strsave(oldp->w_localdir);
  
      /* copy tagstack and folds */
      for (i = 0; i < oldp->w_tagstacklen; i++)
      {
  	newp->w_tagstack[i] = oldp->w_tagstack[i];
  	if (newp->w_tagstack[i].tagname != NULL)
  	    newp->w_tagstack[i].tagname =
  				   vim_strsave(newp->w_tagstack[i].tagname);
      }
      newp->w_tagstackidx = oldp->w_tagstackidx;
      newp->w_tagstacklen = oldp->w_tagstacklen;
  #ifdef FEAT_FOLDING
      copyFoldingState(oldp, newp);
  #endif
  
      win_init_some(newp, oldp);
  
  #ifdef FEAT_SYN_HL
      check_colorcolumn(newp);
  #endif
  }
  
  /*
   * Initialize window "newp" from window"old".
   * Only the essential things are copied.
   */
      static void
  win_init_some(newp, oldp)
      win_T	*newp;
      win_T	*oldp;
  {
      /* Use the same argument list. */
      newp->w_alist = oldp->w_alist;
      ++newp->w_alist->al_refcount;
      newp->w_arg_idx = oldp->w_arg_idx;
  
      /* copy options from existing window */
      win_copy_options(oldp, newp);
  }
  
  #endif /* FEAT_WINDOWS */
  
  #if defined(FEAT_WINDOWS) || defined(PROTO)
  /*
   * Check if "win" is a pointer to an existing window.
   */
      int
  win_valid(win)
      win_T	*win;
  {
      win_T	*wp;
  
      if (win == NULL)
  	return FALSE;
      for (wp = firstwin; wp != NULL; wp = wp->w_next)
  	if (wp == win)
  	    return TRUE;
      return FALSE;
  }
  
  /*
   * Return the number of windows.
   */
      int
  win_count()
  {
      win_T	*wp;
      int		count = 0;
  
      for (wp = firstwin; wp != NULL; wp = wp->w_next)
  	++count;
      return count;
  }
  
  /*
   * Make "count" windows on the screen.
   * Return actual number of windows on the screen.
   * Must be called when there is just one window, filling the whole screen
   * (excluding the command line).
   */
      int
  make_windows(count, vertical)
      int		count;
      int		vertical UNUSED;  /* split windows vertically if TRUE */
  {
      int		maxcount;
      int		todo;
  
  #ifdef FEAT_VERTSPLIT
      if (vertical)
      {
  	/* Each windows needs at least 'winminwidth' lines and a separator
  	 * column. */
  	maxcount = (curwin->w_width + curwin->w_vsep_width
  					     - (p_wiw - p_wmw)) / (p_wmw + 1);
      }
      else
  #endif
      {
  	/* Each window needs at least 'winminheight' lines and a status line. */
  	maxcount = (curwin->w_height + curwin->w_status_height
  				  - (p_wh - p_wmh)) / (p_wmh + STATUS_HEIGHT);
      }
  
      if (maxcount < 2)
  	maxcount = 2;
      if (count > maxcount)
  	count = maxcount;
  
      /*
       * add status line now, otherwise first window will be too big
       */
      if (count > 1)
  	last_status(TRUE);
  
  #ifdef FEAT_AUTOCMD
      /*
       * Don't execute autocommands while creating the windows.  Must do that
       * when putting the buffers in the windows.
       */
      block_autocmds();
  #endif
  
      /* todo is number of windows left to create */
      for (todo = count - 1; todo > 0; --todo)
  #ifdef FEAT_VERTSPLIT
  	if (vertical)
  	{
  	    if (win_split(curwin->w_width - (curwin->w_width - todo)
  			/ (todo + 1) - 1, WSP_VERT | WSP_ABOVE) == FAIL)
  		break;
  	}
  	else
  #endif
  	{
  	    if (win_split(curwin->w_height - (curwin->w_height - todo
  			    * STATUS_HEIGHT) / (todo + 1)
  			- STATUS_HEIGHT, WSP_ABOVE) == FAIL)
  		break;
  	}
  
  #ifdef FEAT_AUTOCMD
      unblock_autocmds();
  #endif
  
      /* return actual number of windows */
      return (count - todo);
  }
  
  /*
   * Exchange current and next window
   */
      static void
  win_exchange(Prenum)
      long	Prenum;
  {
      frame_T	*frp;
      frame_T	*frp2;
      win_T	*wp;
      win_T	*wp2;
      int		temp;
  
      if (lastwin == firstwin)	    /* just one window */
      {
  	beep_flush();
  	return;
      }
  
  #ifdef FEAT_GUI
      need_mouse_correct = TRUE;
  #endif
  
      /*
       * find window to exchange with
       */
      if (Prenum)
      {
  	frp = curwin->w_frame->fr_parent->fr_child;
  	while (frp != NULL && --Prenum > 0)
  	    frp = frp->fr_next;
      }
      else if (curwin->w_frame->fr_next != NULL)	/* Swap with next */
  	frp = curwin->w_frame->fr_next;
      else    /* Swap last window in row/col with previous */
  	frp = curwin->w_frame->fr_prev;
  
      /* We can only exchange a window with another window, not with a frame
       * containing windows. */
      if (frp == NULL || frp->fr_win == NULL || frp->fr_win == curwin)
  	return;
      wp = frp->fr_win;
  
  /*
   * 1. remove curwin from the list. Remember after which window it was in wp2
   * 2. insert curwin before wp in the list
   * if wp != wp2
   *    3. remove wp from the list
   *    4. insert wp after wp2
   * 5. exchange the status line height and vsep width.
   */
      wp2 = curwin->w_prev;
      frp2 = curwin->w_frame->fr_prev;
      if (wp->w_prev != curwin)
      {
  	win_remove(curwin, NULL);
  	frame_remove(curwin->w_frame);
  	win_append(wp->w_prev, curwin);
  	frame_insert(frp, curwin->w_frame);
      }
      if (wp != wp2)
      {
  	win_remove(wp, NULL);
  	frame_remove(wp->w_frame);
  	win_append(wp2, wp);
  	if (frp2 == NULL)
  	    frame_insert(wp->w_frame->fr_parent->fr_child, wp->w_frame);
  	else
  	    frame_append(frp2, wp->w_frame);
      }
      temp = curwin->w_status_height;
      curwin->w_status_height = wp->w_status_height;
      wp->w_status_height = temp;
  #ifdef FEAT_VERTSPLIT
      temp = curwin->w_vsep_width;
      curwin->w_vsep_width = wp->w_vsep_width;
      wp->w_vsep_width = temp;
  
      /* If the windows are not in the same frame, exchange the sizes to avoid
       * messing up the window layout.  Otherwise fix the frame sizes. */
      if (curwin->w_frame->fr_parent != wp->w_frame->fr_parent)
      {
  	temp = curwin->w_height;
  	curwin->w_height = wp->w_height;
  	wp->w_height = temp;
  	temp = curwin->w_width;
  	curwin->w_width = wp->w_width;
  	wp->w_width = temp;
      }
      else
      {
  	frame_fix_height(curwin);
  	frame_fix_height(wp);
  	frame_fix_width(curwin);
  	frame_fix_width(wp);
      }
  #endif
  
      (void)win_comp_pos();		/* recompute window positions */
  
      win_enter(wp, TRUE);
      redraw_later(CLEAR);
  }
  
  /*
   * rotate windows: if upwards TRUE the second window becomes the first one
   *		   if upwards FALSE the first window becomes the second one
   */
      static void
  win_rotate(upwards, count)
      int		upwards;
      int		count;
  {
      win_T	*wp1;
      win_T	*wp2;
      frame_T	*frp;
      int		n;
  
      if (firstwin == lastwin)		/* nothing to do */
      {
  	beep_flush();
  	return;
      }
  
  #ifdef FEAT_GUI
      need_mouse_correct = TRUE;
  #endif
  
  #ifdef FEAT_VERTSPLIT
      /* Check if all frames in this row/col have one window. */
      for (frp = curwin->w_frame->fr_parent->fr_child; frp != NULL;
  							   frp = frp->fr_next)
  	if (frp->fr_win == NULL)
  	{
  	    EMSG(_("E443: Cannot rotate when another window is split"));
  	    return;
  	}
  #endif
  
      while (count--)
      {
  	if (upwards)		/* first window becomes last window */
  	{
  	    /* remove first window/frame from the list */
  	    frp = curwin->w_frame->fr_parent->fr_child;
  	    wp1 = frp->fr_win;
  	    win_remove(wp1, NULL);
  	    frame_remove(frp);
  
  	    /* find last frame and append removed window/frame after it */
  	    for ( ; frp->fr_next != NULL; frp = frp->fr_next)
  		;
  	    win_append(frp->fr_win, wp1);
  	    frame_append(frp, wp1->w_frame);
  
  	    wp2 = frp->fr_win;		/* previously last window */
  	}
  	else			/* last window becomes first window */
  	{
  	    /* find last window/frame in the list and remove it */
  	    for (frp = curwin->w_frame; frp->fr_next != NULL;
  							   frp = frp->fr_next)
  		;
  	    wp1 = frp->fr_win;
  	    wp2 = wp1->w_prev;		    /* will become last window */
  	    win_remove(wp1, NULL);
  	    frame_remove(frp);
  
  	    /* append the removed window/frame before the first in the list */
  	    win_append(frp->fr_parent->fr_child->fr_win->w_prev, wp1);
  	    frame_insert(frp->fr_parent->fr_child, frp);
  	}
  
  	/* exchange status height and vsep width of old and new last window */
  	n = wp2->w_status_height;
  	wp2->w_status_height = wp1->w_status_height;
  	wp1->w_status_height = n;
  	frame_fix_height(wp1);
  	frame_fix_height(wp2);
  #ifdef FEAT_VERTSPLIT
  	n = wp2->w_vsep_width;
  	wp2->w_vsep_width = wp1->w_vsep_width;
  	wp1->w_vsep_width = n;
  	frame_fix_width(wp1);
  	frame_fix_width(wp2);
  #endif
  
  	    /* recompute w_winrow and w_wincol for all windows */
  	(void)win_comp_pos();
      }
  
      redraw_later(CLEAR);
  }
  
  /*
   * Move the current window to the very top/bottom/left/right of the screen.
   */
      static void
  win_totop(size, flags)
      int		size;
      int		flags;
  {
      int		dir;
      int		height = curwin->w_height;
  
      if (lastwin == firstwin)
      {
  	beep_flush();
  	return;
      }
  
      /* Remove the window and frame from the tree of frames. */
      (void)winframe_remove(curwin, &dir, NULL);
      win_remove(curwin, NULL);
      last_status(FALSE);	    /* may need to remove last status line */
      (void)win_comp_pos();   /* recompute window positions */
  
      /* Split a window on the desired side and put the window there. */
      (void)win_split_ins(size, flags, curwin, dir);
      if (!(flags & WSP_VERT))
      {
  	win_setheight(height);
  	if (p_ea)
  	    win_equal(curwin, TRUE, 'v');
      }
  
  #if defined(FEAT_GUI) && defined(FEAT_VERTSPLIT)
      /* When 'guioptions' includes 'L' or 'R' may have to remove or add
       * scrollbars.  Have to update them anyway. */
      gui_may_update_scrollbars();
  #endif
  }
  
  /*
   * Move window "win1" to below/right of "win2" and make "win1" the current
   * window.  Only works within the same frame!
   */
      void
  win_move_after(win1, win2)
      win_T	*win1, *win2;
  {
      int		height;
  
      /* check if the arguments are reasonable */
      if (win1 == win2)
  	return;
  
      /* check if there is something to do */
      if (win2->w_next != win1)
      {
  	/* may need move the status line/vertical separator of the last window
  	 * */
  	if (win1 == lastwin)
  	{
  	    height = win1->w_prev->w_status_height;
  	    win1->w_prev->w_status_height = win1->w_status_height;
  	    win1->w_status_height = height;
  #ifdef FEAT_VERTSPLIT
  	    if (win1->w_prev->w_vsep_width == 1)
  	    {
  		/* Remove the vertical separator from the last-but-one window,
  		 * add it to the last window.  Adjust the frame widths. */
  		win1->w_prev->w_vsep_width = 0;
  		win1->w_prev->w_frame->fr_width -= 1;
  		win1->w_vsep_width = 1;
  		win1->w_frame->fr_width += 1;
  	    }
  #endif
  	}
  	else if (win2 == lastwin)
  	{
  	    height = win1->w_status_height;
  	    win1->w_status_height = win2->w_status_height;
  	    win2->w_status_height = height;
  #ifdef FEAT_VERTSPLIT
  	    if (win1->w_vsep_width == 1)
  	    {
  		/* Remove the vertical separator from win1, add it to the last
  		 * window, win2.  Adjust the frame widths. */
  		win2->w_vsep_width = 1;
  		win2->w_frame->fr_width += 1;
  		win1->w_vsep_width = 0;
  		win1->w_frame->fr_width -= 1;
  	    }
  #endif
  	}
  	win_remove(win1, NULL);
  	frame_remove(win1->w_frame);
  	win_append(win2, win1);
  	frame_append(win2->w_frame, win1->w_frame);
  
  	(void)win_comp_pos();	/* recompute w_winrow for all windows */
  	redraw_later(NOT_VALID);
      }
      win_enter(win1, FALSE);
  }
  
  /*
   * Make all windows the same height.
   * 'next_curwin' will soon be the current window, make sure it has enough
   * rows.
   */
      void
  win_equal(next_curwin, current, dir)
      win_T	*next_curwin;	/* pointer to current window to be or NULL */
      int		current;	/* do only frame with current window */
      int		dir;		/* 'v' for vertically, 'h' for horizontally,
  				   'b' for both, 0 for using p_ead */
  {
      if (dir == 0)
  #ifdef FEAT_VERTSPLIT
  	dir = *p_ead;
  #else
  	dir = 'b';
  #endif
      win_equal_rec(next_curwin == NULL ? curwin : next_curwin, current,
  		      topframe, dir, 0, tabline_height(),
  					   (int)Columns, topframe->fr_height);
  }
  
  /*
   * Set a frame to a new position and height, spreading the available room
   * equally over contained frames.
   * The window "next_curwin" (if not NULL) should at least get the size from
   * 'winheight' and 'winwidth' if possible.
   */
      static void
  win_equal_rec(next_curwin, current, topfr, dir, col, row, width, height)
      win_T	*next_curwin;	/* pointer to current window to be or NULL */
      int		current;	/* do only frame with current window */
      frame_T	*topfr;		/* frame to set size off */
      int		dir;		/* 'v', 'h' or 'b', see win_equal() */
      int		col;		/* horizontal position for frame */
      int		row;		/* vertical position for frame */
      int		width;		/* new width of frame */
      int		height;		/* new height of frame */
  {
      int		n, m;
      int		extra_sep = 0;
      int		wincount, totwincount = 0;
      frame_T	*fr;
      int		next_curwin_size = 0;
      int		room = 0;
      int		new_size;
      int		has_next_curwin = 0;
      int		hnc;
  
      if (topfr->fr_layout == FR_LEAF)
      {
  	/* Set the width/height of this frame.
  	 * Redraw when size or position changes */
  	if (topfr->fr_height != height || topfr->fr_win->w_winrow != row
  #ifdef FEAT_VERTSPLIT
  		|| topfr->fr_width != width || topfr->fr_win->w_wincol != col
  #endif
  	   )
  	{
  	    topfr->fr_win->w_winrow = row;
  	    frame_new_height(topfr, height, FALSE, FALSE);
  #ifdef FEAT_VERTSPLIT
  	    topfr->fr_win->w_wincol = col;
  	    frame_new_width(topfr, width, FALSE, FALSE);
  #endif
  	    redraw_all_later(CLEAR);
  	}
      }
  #ifdef FEAT_VERTSPLIT
      else if (topfr->fr_layout == FR_ROW)
      {
  	topfr->fr_width = width;
  	topfr->fr_height = height;
  
  	if (dir != 'v')			/* equalize frame widths */
  	{
  	    /* Compute the maximum number of windows horizontally in this
  	     * frame. */
  	    n = frame_minwidth(topfr, NOWIN);
  	    /* add one for the rightmost window, it doesn't have a separator */
  	    if (col + width == Columns)
  		extra_sep = 1;
  	    else
  		extra_sep = 0;
  	    totwincount = (n + extra_sep) / (p_wmw + 1);
  	    has_next_curwin = frame_has_win(topfr, next_curwin);
  
  	    /*
  	     * Compute width for "next_curwin" window and room available for
  	     * other windows.
  	     * "m" is the minimal width when counting p_wiw for "next_curwin".
  	     */
  	    m = frame_minwidth(topfr, next_curwin);
  	    room = width - m;
  	    if (room < 0)
  	    {
  		next_curwin_size = p_wiw + room;
  		room = 0;
  	    }
  	    else
  	    {
  		next_curwin_size = -1;
  		for (fr = topfr->fr_child; fr != NULL; fr = fr->fr_next)
  		{
  		    /* If 'winfixwidth' set keep the window width if
  		     * possible.
  		     * Watch out for this window being the next_curwin. */
  		    if (frame_fixed_width(fr))
  		    {
  			n = frame_minwidth(fr, NOWIN);
  			new_size = fr->fr_width;
  			if (frame_has_win(fr, next_curwin))
  			{
  			    room += p_wiw - p_wmw;
  			    next_curwin_size = 0;
  			    if (new_size < p_wiw)
  				new_size = p_wiw;
  			}
  			else
  			    /* These windows don't use up room. */
  			    totwincount -= (n + (fr->fr_next == NULL
  					      ? extra_sep : 0)) / (p_wmw + 1);
  			room -= new_size - n;
  			if (room < 0)
  			{
  			    new_size += room;
  			    room = 0;
  			}
  			fr->fr_newwidth = new_size;
  		    }
  		}
  		if (next_curwin_size == -1)
  		{
  		    if (!has_next_curwin)
  			next_curwin_size = 0;
  		    else if (totwincount > 1
  			    && (room + (totwincount - 2))
  						  / (totwincount - 1) > p_wiw)
  		    {
  			/* Can make all windows wider than 'winwidth', spread
  			 * the room equally. */
  			next_curwin_size = (room + p_wiw
  					    + (totwincount - 1) * p_wmw
  					    + (totwincount - 1)) / totwincount;
  			room -= next_curwin_size - p_wiw;
  		    }
  		    else
  			next_curwin_size = p_wiw;
  		}
  	    }
  
  	    if (has_next_curwin)
  		--totwincount;		/* don't count curwin */
  	}
  
  	for (fr = topfr->fr_child; fr != NULL; fr = fr->fr_next)
  	{
  	    n = m = 0;
  	    wincount = 1;
  	    if (fr->fr_next == NULL)
  		/* last frame gets all that remains (avoid roundoff error) */
  		new_size = width;
  	    else if (dir == 'v')
  		new_size = fr->fr_width;
  	    else if (frame_fixed_width(fr))
  	    {
  		new_size = fr->fr_newwidth;
  		wincount = 0;	    /* doesn't count as a sizeable window */
  	    }
  	    else
  	    {
  		/* Compute the maximum number of windows horiz. in "fr". */
  		n = frame_minwidth(fr, NOWIN);
  		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
  								/ (p_wmw + 1);
  		m = frame_minwidth(fr, next_curwin);
  		if (has_next_curwin)
  		    hnc = frame_has_win(fr, next_curwin);
  		else
  		    hnc = FALSE;
  		if (hnc)	    /* don't count next_curwin */
  		    --wincount;
  		if (totwincount == 0)
  		    new_size = room;
  		else
  		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
  								/ totwincount;
  		if (hnc)	    /* add next_curwin size */
  		{
  		    next_curwin_size -= p_wiw - (m - n);
  		    new_size += next_curwin_size;
  		    room -= new_size - next_curwin_size;
  		}
  		else
  		    room -= new_size;
  		new_size += n;
  	    }
  
  	    /* Skip frame that is full width when splitting or closing a
  	     * window, unless equalizing all frames. */
  	    if (!current || dir != 'v' || topfr->fr_parent != NULL
  		    || (new_size != fr->fr_width)
  		    || frame_has_win(fr, next_curwin))
  		win_equal_rec(next_curwin, current, fr, dir, col, row,
  							    new_size, height);
  	    col += new_size;
  	    width -= new_size;
  	    totwincount -= wincount;
  	}
      }
  #endif
      else /* topfr->fr_layout == FR_COL */
      {
  #ifdef FEAT_VERTSPLIT
  	topfr->fr_width = width;
  #endif
  	topfr->fr_height = height;
  
  	if (dir != 'h')			/* equalize frame heights */
  	{
  	    /* Compute maximum number of windows vertically in this frame. */
  	    n = frame_minheight(topfr, NOWIN);
  	    /* add one for the bottom window if it doesn't have a statusline */
  	    if (row + height == cmdline_row && p_ls == 0)
  		extra_sep = 1;
  	    else
  		extra_sep = 0;
  	    totwincount = (n + extra_sep) / (p_wmh + 1);
  	    has_next_curwin = frame_has_win(topfr, next_curwin);
  
  	    /*
  	     * Compute height for "next_curwin" window and room available for
  	     * other windows.
  	     * "m" is the minimal height when counting p_wh for "next_curwin".
  	     */
  	    m = frame_minheight(topfr, next_curwin);
  	    room = height - m;
  	    if (room < 0)
  	    {
  		/* The room is less then 'winheight', use all space for the
  		 * current window. */
  		next_curwin_size = p_wh + room;
  		room = 0;
  	    }
  	    else
  	    {
  		next_curwin_size = -1;
  		for (fr = topfr->fr_child; fr != NULL; fr = fr->fr_next)
  		{
  		    /* If 'winfixheight' set keep the window height if
  		     * possible.
  		     * Watch out for this window being the next_curwin. */
  		    if (frame_fixed_height(fr))
  		    {
  			n = frame_minheight(fr, NOWIN);
  			new_size = fr->fr_height;
  			if (frame_has_win(fr, next_curwin))
  			{
  			    room += p_wh - p_wmh;
  			    next_curwin_size = 0;
  			    if (new_size < p_wh)
  				new_size = p_wh;
  			}
  			else
  			    /* These windows don't use up room. */
  			    totwincount -= (n + (fr->fr_next == NULL
  					      ? extra_sep : 0)) / (p_wmh + 1);
  			room -= new_size - n;
  			if (room < 0)
  			{
  			    new_size += room;
  			    room = 0;
  			}
  			fr->fr_newheight = new_size;
  		    }
  		}
  		if (next_curwin_size == -1)
  		{
  		    if (!has_next_curwin)
  			next_curwin_size = 0;
  		    else if (totwincount > 1
  			    && (room + (totwincount - 2))
  						   / (totwincount - 1) > p_wh)
  		    {
  			/* can make all windows higher than 'winheight',
  			 * spread the room equally. */
  			next_curwin_size = (room + p_wh
  					   + (totwincount - 1) * p_wmh
  					   + (totwincount - 1)) / totwincount;
  			room -= next_curwin_size - p_wh;
  		    }
  		    else
  			next_curwin_size = p_wh;
  		}
  	    }
  
  	    if (has_next_curwin)
  		--totwincount;		/* don't count curwin */
  	}
  
  	for (fr = topfr->fr_child; fr != NULL; fr = fr->fr_next)
  	{
  	    n = m = 0;
  	    wincount = 1;
  	    if (fr->fr_next == NULL)
  		/* last frame gets all that remains (avoid roundoff error) */
  		new_size = height;
  	    else if (dir == 'h')
  		new_size = fr->fr_height;
  	    else if (frame_fixed_height(fr))
  	    {
  		new_size = fr->fr_newheight;
  		wincount = 0;	    /* doesn't count as a sizeable window */
  	    }
  	    else
  	    {
  		/* Compute the maximum number of windows vert. in "fr". */
  		n = frame_minheight(fr, NOWIN);
  		wincount = (n + (fr->fr_next == NULL ? extra_sep : 0))
  								/ (p_wmh + 1);
  		m = frame_minheight(fr, next_curwin);
  		if (has_next_curwin)
  		    hnc = frame_has_win(fr, next_curwin);
  		else
  		    hnc = FALSE;
  		if (hnc)	    /* don't count next_curwin */
  		    --wincount;
  		if (totwincount == 0)
  		    new_size = room;
  		else
  		    new_size = (wincount * room + ((unsigned)totwincount >> 1))
  								/ totwincount;
  		if (hnc)	    /* add next_curwin size */
  		{
  		    next_curwin_size -= p_wh - (m - n);
  		    new_size += next_curwin_size;
  		    room -= new_size - next_curwin_size;
  		}
  		else
  		    room -= new_size;
  		new_size += n;
  	    }
  	    /* Skip frame that is full width when splitting or closing a
  	     * window, unless equalizing all frames. */
  	    if (!current || dir != 'h' || topfr->fr_parent != NULL
  		    || (new_size != fr->fr_height)
  		    || frame_has_win(fr, next_curwin))
  		win_equal_rec(next_curwin, current, fr, dir, col, row,
  							     width, new_size);
  	    row += new_size;
  	    height -= new_size;
  	    totwincount -= wincount;
  	}
      }
  }
  
  /*
   * close all windows for buffer 'buf'
   */
      void
  close_windows(buf, keep_curwin)
      buf_T	*buf;
      int		keep_curwin;	    /* don't close "curwin" */
  {
      win_T	*wp;
      tabpage_T   *tp, *nexttp;
      int		h = tabline_height();
  
      ++RedrawingDisabled;
  
      for (wp = firstwin; wp != NULL && lastwin != firstwin; )
      {
  	if (wp->w_buffer == buf && (!keep_curwin || wp != curwin)
  #ifdef FEAT_AUTOCMD
  		&& !(wp->w_closing || wp->w_buffer->b_closing)
  #endif
  		)
  	{
  	    win_close(wp, FALSE);
  
  	    /* Start all over, autocommands may change the window layout. */
  	    wp = firstwin;
  	}
  	else
  	    wp = wp->w_next;
      }
  
      /* Also check windows in other tab pages. */
      for (tp = first_tabpage; tp != NULL; tp = nexttp)
      {
  	nexttp = tp->tp_next;
  	if (tp != curtab)
  	    for (wp = tp->tp_firstwin; wp != NULL; wp = wp->w_next)
  		if (wp->w_buffer == buf
  #ifdef FEAT_AUTOCMD
  		    && !(wp->w_closing || wp->w_buffer->b_closing)
  #endif
  		    )
  		{
  		    win_close_othertab(wp, FALSE, tp);
  
  		    /* Start all over, the tab page may be closed and
  		     * autocommands may change the window layout. */
  		    nexttp = first_tabpage;
  		    break;
  		}
      }
  
      --RedrawingDisabled;
  
      redraw_tabline = TRUE;
      if (h != tabline_height())
  	shell_new_rows();
  }
  
  /*
   * Return TRUE if the current window is the only window that exists (ignoring
   * "aucmd_win").
   * Returns FALSE if there is a window, possibly in another tab page.
   */
      static int
  last_window()
  {
      return (one_window() && first_tabpage->tp_next == NULL);
  }
  
  /*
   * Return TRUE if there is only one window other than "aucmd_win" in the
   * current tab page.
   */
      int
  one_window()
  {
  #ifdef FEAT_AUTOCMD
      win_T	*wp;
      int		seen_one = FALSE;
  
      FOR_ALL_WINDOWS(wp)
      {
  	if (wp != aucmd_win)
  	{
  	    if (seen_one)
  		return FALSE;
  	    seen_one = TRUE;
  	}
      }
      return TRUE;
  #else
      return firstwin == lastwin;
  #endif
  }
  
  /*
   * Close the possibly last window in a tab page.
   * Returns TRUE when the window was closed already.
   */
      static int
  close_last_window_tabpage(win, free_buf, prev_curtab)
      win_T	*win;
      int		free_buf;
      tabpage_T   *prev_curtab;
  {
      if (firstwin == lastwin)
      {
  #ifdef FEAT_AUTOCMD
  	buf_T	*old_curbuf = curbuf;
  #endif
  
  	/*
  	 * Closing the last window in a tab page.  First go to another tab
  	 * page and then close the window and the tab page.  This avoids that
  	 * curwin and curtab are invalid while we are freeing memory, they may
  	 * be used in GUI events.
  	 * Don't trigger autocommands yet, they may use wrong values, so do
  	 * that below.
  	 */
  	goto_tabpage_tp(alt_tabpage(), FALSE, TRUE);
  	redraw_tabline = TRUE;
  
  	/* Safety check: Autocommands may have closed the window when jumping
  	 * to the other tab page. */
  	if (valid_tabpage(prev_curtab) && prev_curtab->tp_firstwin == win)
  	{
  	    int	    h = tabline_height();
  
  	    win_close_othertab(win, free_buf, prev_curtab);
  	    if (h != tabline_height())
  		shell_new_rows();
  	}
  	/* Since goto_tabpage_tp above did not trigger *Enter autocommands, do
  	 * that now. */
  #ifdef FEAT_AUTOCMD
  	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
  	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
  	if (old_curbuf != curbuf)
  	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
  #endif
  	return TRUE;
      }
      return FALSE;
  }
  
  /*
   * Close window "win".  Only works for the current tab page.
   * If "free_buf" is TRUE related buffer may be unloaded.
   *
   * Called by :quit, :close, :xit, :wq and findtag().
   * Returns FAIL when the window was not closed.
   */
      int
  win_close(win, free_buf)
      win_T	*win;
      int		free_buf;
  {
      win_T	*wp;
  #ifdef FEAT_AUTOCMD
      int		other_buffer = FALSE;
  #endif
      int		close_curwin = FALSE;
      int		dir;
      int		help_window = FALSE;
      tabpage_T   *prev_curtab = curtab;
  
      if (last_window())
      {
  	EMSG(_("E444: Cannot close last window"));
  	return FAIL;
      }
  
  #ifdef FEAT_AUTOCMD
      if (win->w_closing || (win->w_buffer != NULL && win->w_buffer->b_closing))
  	return FAIL; /* window is already being closed */
      if (win == aucmd_win)
      {
  	EMSG(_("E813: Cannot close autocmd window"));
  	return FAIL;
      }
      if ((firstwin == aucmd_win || lastwin == aucmd_win) && one_window())
      {
  	EMSG(_("E814: Cannot close window, only autocmd window would remain"));
  	return FAIL;
      }
  #endif
  
      /* When closing the last window in a tab page first go to another tab page
       * and then close the window and the tab page to avoid that curwin and
       * curtab are invalid while we are freeing memory. */
      if (close_last_window_tabpage(win, free_buf, prev_curtab))
        return FAIL;
  
      /* When closing the help window, try restoring a snapshot after closing
       * the window.  Otherwise clear the snapshot, it's now invalid. */
      if (win->w_buffer != NULL && win->w_buffer->b_help)
  	help_window = TRUE;
      else
  	clear_snapshot(curtab, SNAP_HELP_IDX);
  
  #ifdef FEAT_AUTOCMD
      if (win == curwin)
      {
  	/*
  	 * Guess which window is going to be the new current window.
  	 * This may change because of the autocommands (sigh).
  	 */
  	wp = frame2win(win_altframe(win, NULL));
  
  	/*
  	 * Be careful: If autocommands delete the window or cause this window
  	 * to be the last one left, return now.
  	 */
  	if (wp->w_buffer != curbuf)
  	{
  	    other_buffer = TRUE;
  	    win->w_closing = TRUE;
  	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
  	    if (!win_valid(win))
  		return FAIL;
  	    win->w_closing = FALSE;
  	    if (last_window())
  		return FAIL;
  	}
  	win->w_closing = TRUE;
  	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
  	if (!win_valid(win))
  	    return FAIL;
  	win->w_closing = FALSE;
  	if (last_window())
  	    return FAIL;
  # ifdef FEAT_EVAL
  	/* autocmds may abort script processing */
  	if (aborting())
  	    return FAIL;
  # endif
      }
  #endif
  
  #ifdef FEAT_GUI
      /* Avoid trouble with scrollbars that are going to be deleted in
       * win_free(). */
      if (gui.in_use)
  	out_flush();
  #endif
  
  #ifdef FEAT_SYN_HL
      /* Free independent synblock before the buffer is freed. */
      if (win->w_buffer != NULL)
  	reset_synblock(win);
  #endif
  
      /*
       * Close the link to the buffer.
       */
      if (win->w_buffer != NULL)
      {
  #ifdef FEAT_AUTOCMD
  	win->w_closing = TRUE;
  #endif
  	close_buffer(win, win->w_buffer, free_buf ? DOBUF_UNLOAD : 0, TRUE);
  #ifdef FEAT_AUTOCMD
  	if (win_valid(win))
  	    win->w_closing = FALSE;
  #endif
      }
  
      if (only_one_window() && win_valid(win) && win->w_buffer == NULL
  	    && (last_window() || curtab != prev_curtab
  		|| close_last_window_tabpage(win, free_buf, prev_curtab)))
      {
  	/* Autocommands have close all windows, quit now.  Restore
  	 * curwin->w_buffer, otherwise writing viminfo may fail. */
  	if (curwin->w_buffer == NULL)
  	    curwin->w_buffer = curbuf;
  	getout(0);
      }
  
      /* Autocommands may have closed the window already, or closed the only
       * other window or moved to another tab page. */
      else if (!win_valid(win) || last_window() || curtab != prev_curtab
  	    || close_last_window_tabpage(win, free_buf, prev_curtab))
  	return FAIL;
  
      /* Free the memory used for the window and get the window that received
       * the screen space. */
      wp = win_free_mem(win, &dir, NULL);
  
      /* Make sure curwin isn't invalid.  It can cause severe trouble when
       * printing an error message.  For win_equal() curbuf needs to be valid
       * too. */
      if (win == curwin)
      {
  	curwin = wp;
  #ifdef FEAT_QUICKFIX
  	if (wp->w_p_pvw || bt_quickfix(wp->w_buffer))
  	{
  	    /*
  	     * If the cursor goes to the preview or the quickfix window, try
  	     * finding another window to go to.
  	     */
  	    for (;;)
  	    {
  		if (wp->w_next == NULL)
  		    wp = firstwin;
  		else
  		    wp = wp->w_next;
  		if (wp == curwin)
  		    break;
  		if (!wp->w_p_pvw && !bt_quickfix(wp->w_buffer))
  		{
  		    curwin = wp;
  		    break;
  		}
  	    }
  	}
  #endif
  	curbuf = curwin->w_buffer;
  	close_curwin = TRUE;
      }
      if (p_ea
  #ifdef FEAT_VERTSPLIT
  	    && (*p_ead == 'b' || *p_ead == dir)
  #endif
  	    )
  	win_equal(curwin, TRUE,
  #ifdef FEAT_VERTSPLIT
  		dir
  #else
  		0
  #endif
  		);
      else
  	win_comp_pos();
      if (close_curwin)
      {
  	win_enter_ext(wp, FALSE, TRUE, TRUE, TRUE);
  #ifdef FEAT_AUTOCMD
  	if (other_buffer)
  	    /* careful: after this wp and win may be invalid! */
  	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
  #endif
      }
  
      /*
       * If last window has a status line now and we don't want one,
       * remove the status line.
       */
      last_status(FALSE);
  
      /* After closing the help window, try restoring the window layout from
       * before it was opened. */
      if (help_window)
  	restore_snapshot(SNAP_HELP_IDX, close_curwin);
  
  #if defined(FEAT_GUI) && defined(FEAT_VERTSPLIT)
      /* When 'guioptions' includes 'L' or 'R' may have to remove scrollbars. */
      if (gui.in_use && !win_hasvertsplit())
  	gui_init_which_components(NULL);
  #endif
  
      redraw_all_later(NOT_VALID);
      return OK;
  }
  
  /*
   * Close window "win" in tab page "tp", which is not the current tab page.
   * This may be the last window in that tab page and result in closing the tab,
   * thus "tp" may become invalid!
   * Caller must check if buffer is hidden and whether the tabline needs to be
   * updated.
   */
      void
  win_close_othertab(win, free_buf, tp)
      win_T	*win;
      int		free_buf;
      tabpage_T	*tp;
  {
      win_T	*wp;
      int		dir;
      tabpage_T   *ptp = NULL;
      int		free_tp = FALSE;
  
  #ifdef FEAT_AUTOCMD
      if (win->w_closing || win->w_buffer->b_closing)
  	return; /* window is already being closed */
  #endif
  
      /* Close the link to the buffer. */
      close_buffer(win, win->w_buffer, free_buf ? DOBUF_UNLOAD : 0, FALSE);
  
      /* Careful: Autocommands may have closed the tab page or made it the
       * current tab page.  */
      for (ptp = first_tabpage; ptp != NULL && ptp != tp; ptp = ptp->tp_next)
  	;
      if (ptp == NULL || tp == curtab)
  	return;
  
      /* Autocommands may have closed the window already. */
      for (wp = tp->tp_firstwin; wp != NULL && wp != win; wp = wp->w_next)
  	;
      if (wp == NULL)
  	return;
  
      /* When closing the last window in a tab page remove the tab page. */
      if (tp == NULL ? firstwin == lastwin : tp->tp_firstwin == tp->tp_lastwin)
      {
  	if (tp == first_tabpage)
  	    first_tabpage = tp->tp_next;
  	else
  	{
  	    for (ptp = first_tabpage; ptp != NULL && ptp->tp_next != tp;
  							   ptp = ptp->tp_next)
  		;
  	    if (ptp == NULL)
  	    {
  		EMSG2(_(e_intern2), "win_close_othertab()");
  		return;
  	    }
  	    ptp->tp_next = tp->tp_next;
  	}
  	free_tp = TRUE;
      }
  
      /* Free the memory used for the window. */
      win_free_mem(win, &dir, tp);
  
      if (free_tp)
  	free_tabpage(tp);
  }
  
  /*
   * Free the memory used for a window.
   * Returns a pointer to the window that got the freed up space.
   */
      static win_T *
  win_free_mem(win, dirp, tp)
      win_T	*win;
      int		*dirp;		/* set to 'v' or 'h' for direction if 'ea' */
      tabpage_T	*tp;		/* tab page "win" is in, NULL for current */
  {
      frame_T	*frp;
      win_T	*wp;
  
      /* Remove the window and its frame from the tree of frames. */
      frp = win->w_frame;
      wp = winframe_remove(win, dirp, tp);
      vim_free(frp);
      win_free(win, tp);
  
      /* When deleting the current window of another tab page select a new
       * current window. */
      if (tp != NULL && win == tp->tp_curwin)
  	tp->tp_curwin = wp;
  
      return wp;
  }
  
  #if defined(EXITFREE) || defined(PROTO)
      void
  win_free_all()
  {
      int		dummy;
  
  # ifdef FEAT_WINDOWS
      while (first_tabpage->tp_next != NULL)
  	tabpage_close(TRUE);
  # endif
  
  # ifdef FEAT_AUTOCMD
      if (aucmd_win != NULL)
      {
  	(void)win_free_mem(aucmd_win, &dummy, NULL);
  	aucmd_win = NULL;
      }
  # endif
  
      while (firstwin != NULL)
  	(void)win_free_mem(firstwin, &dummy, NULL);
  }
  #endif
  
  /*
   * Remove a window and its frame from the tree of frames.
   * Returns a pointer to the window that got the freed up space.
   */
      win_T *
  winframe_remove(win, dirp, tp)
      win_T	*win;
      int		*dirp UNUSED;	/* set to 'v' or 'h' for direction if 'ea' */
      tabpage_T	*tp;		/* tab page "win" is in, NULL for current */
  {
      frame_T	*frp, *frp2, *frp3;
      frame_T	*frp_close = win->w_frame;
      win_T	*wp;
  
      /*
       * If there is only one window there is nothing to remove.
       */
      if (tp == NULL ? firstwin == lastwin : tp->tp_firstwin == tp->tp_lastwin)
  	return NULL;
  
      /*
       * Remove the window from its frame.
       */
      frp2 = win_altframe(win, tp);
      wp = frame2win(frp2);
  
      /* Remove this frame from the list of frames. */
      frame_remove(frp_close);
  
  #ifdef FEAT_VERTSPLIT
      if (frp_close->fr_parent->fr_layout == FR_COL)
      {
  #endif
  	/* When 'winfixheight' is set, try to find another frame in the column
  	 * (as close to the closed frame as possible) to distribute the height
  	 * to. */
  	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfh)
  	{
  	    frp = frp_close->fr_prev;
  	    frp3 = frp_close->fr_next;
  	    while (frp != NULL || frp3 != NULL)
  	    {
  		if (frp != NULL)
  		{
  		    if (frp->fr_win != NULL && !frp->fr_win->w_p_wfh)
  		    {
  			frp2 = frp;
  			wp = frp->fr_win;
  			break;
  		    }
  		    frp = frp->fr_prev;
  		}
  		if (frp3 != NULL)
  		{
  		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfh)
  		    {
  			frp2 = frp3;
  			wp = frp3->fr_win;
  			break;
  		    }
  		    frp3 = frp3->fr_next;
  		}
  	    }
  	}
  	frame_new_height(frp2, frp2->fr_height + frp_close->fr_height,
  			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
  #ifdef FEAT_VERTSPLIT
  	*dirp = 'v';
      }
      else
      {
  	/* When 'winfixwidth' is set, try to find another frame in the column
  	 * (as close to the closed frame as possible) to distribute the width
  	 * to. */
  	if (frp2->fr_win != NULL && frp2->fr_win->w_p_wfw)
  	{
  	    frp = frp_close->fr_prev;
  	    frp3 = frp_close->fr_next;
  	    while (frp != NULL || frp3 != NULL)
  	    {
  		if (frp != NULL)
  		{
  		    if (frp->fr_win != NULL && !frp->fr_win->w_p_wfw)
  		    {
  			frp2 = frp;
  			wp = frp->fr_win;
  			break;
  		    }
  		    frp = frp->fr_prev;
  		}
  		if (frp3 != NULL)
  		{
  		    if (frp3->fr_win != NULL && !frp3->fr_win->w_p_wfw)
  		    {
  			frp2 = frp3;
  			wp = frp3->fr_win;
  			break;
  		    }
  		    frp3 = frp3->fr_next;
  		}
  	    }
  	}
  	frame_new_width(frp2, frp2->fr_width + frp_close->fr_width,
  			    frp2 == frp_close->fr_next ? TRUE : FALSE, FALSE);
  	*dirp = 'h';
      }
  #endif
  
      /* If rows/columns go to a window below/right its positions need to be
       * updated.  Can only be done after the sizes have been updated. */
      if (frp2 == frp_close->fr_next)
      {
  	int row = win->w_winrow;
  	int col = W_WINCOL(win);
  
  	frame_comp_pos(frp2, &row, &col);
      }
  
      if (frp2->fr_next == NULL && frp2->fr_prev == NULL)
      {
  	/* There is no other frame in this list, move its info to the parent
  	 * and remove it. */
  	frp2->fr_parent->fr_layout = frp2->fr_layout;
  	frp2->fr_parent->fr_child = frp2->fr_child;
  	for (frp = frp2->fr_child; frp != NULL; frp = frp->fr_next)
  	    frp->fr_parent = frp2->fr_parent;
  	frp2->fr_parent->fr_win = frp2->fr_win;
  	if (frp2->fr_win != NULL)
  	    frp2->fr_win->w_frame = frp2->fr_parent;
  	frp = frp2->fr_parent;
  	vim_free(frp2);
  
  	frp2 = frp->fr_parent;
  	if (frp2 != NULL && frp2->fr_layout == frp->fr_layout)
  	{
  	    /* The frame above the parent has the same layout, have to merge
  	     * the frames into this list. */
  	    if (frp2->fr_child == frp)
  		frp2->fr_child = frp->fr_child;
  	    frp->fr_child->fr_prev = frp->fr_prev;
  	    if (frp->fr_prev != NULL)
  		frp->fr_prev->fr_next = frp->fr_child;
  	    for (frp3 = frp->fr_child; ; frp3 = frp3->fr_next)
  	    {
  		frp3->fr_parent = frp2;
  		if (frp3->fr_next == NULL)
  		{
  		    frp3->fr_next = frp->fr_next;
  		    if (frp->fr_next != NULL)
  			frp->fr_next->fr_prev = frp3;
  		    break;
  		}
  	    }
  	    vim_free(frp);
  	}
      }
  
      return wp;
  }
  
  /*
   * Find out which frame is going to get the freed up space when "win" is
   * closed.
   * if 'splitbelow'/'splitleft' the space goes to the window above/left.
   * if 'nosplitbelow'/'nosplitleft' the space goes to the window below/right.
   * This makes opening a window and closing it immediately keep the same window
   * layout.
   */
      static frame_T *
  win_altframe(win, tp)
      win_T	*win;
      tabpage_T	*tp;		/* tab page "win" is in, NULL for current */
  {
      frame_T	*frp;
      int		b;
  
      if (tp == NULL ? firstwin == lastwin : tp->tp_firstwin == tp->tp_lastwin)
  	/* Last window in this tab page, will go to next tab page. */
  	return alt_tabpage()->tp_curwin->w_frame;
  
      frp = win->w_frame;
  #ifdef FEAT_VERTSPLIT
      if (frp->fr_parent != NULL && frp->fr_parent->fr_layout == FR_ROW)
  	b = p_spr;
      else
  #endif
  	b = p_sb;
      if ((!b && frp->fr_next != NULL) || frp->fr_prev == NULL)
  	return frp->fr_next;
      return frp->fr_prev;
  }
  
  /*
   * Return the tabpage that will be used if the current one is closed.
   */
      static tabpage_T *
  alt_tabpage()
  {
      tabpage_T	*tp;
  
      /* Use the next tab page if possible. */
      if (curtab->tp_next != NULL)
  	return curtab->tp_next;
  
      /* Find the last but one tab page. */
      for (tp = first_tabpage; tp->tp_next != curtab; tp = tp->tp_next)
  	;
      return tp;
  }
  
  /*
   * Find the left-upper window in frame "frp".
   */
      static win_T *
  frame2win(frp)
      frame_T	*frp;
  {
      while (frp->fr_win == NULL)
  	frp = frp->fr_child;
      return frp->fr_win;
  }
  
  /*
   * Return TRUE if frame "frp" contains window "wp".
   */
      static int
  frame_has_win(frp, wp)
      frame_T	*frp;
      win_T	*wp;
  {
      frame_T	*p;
  
      if (frp->fr_layout == FR_LEAF)
  	return frp->fr_win == wp;
  
      for (p = frp->fr_child; p != NULL; p = p->fr_next)
  	if (frame_has_win(p, wp))
  	    return TRUE;
      return FALSE;
  }
  
  /*
   * Set a new height for a frame.  Recursively sets the height for contained
   * frames and windows.  Caller must take care of positions.
   */
      static void
  frame_new_height(topfrp, height, topfirst, wfh)
      frame_T	*topfrp;
      int		height;
      int		topfirst;	/* resize topmost contained frame first */
      int		wfh;		/* obey 'winfixheight' when there is a choice;
  				   may cause the height not to be set */
  {
      frame_T	*frp;
      int		extra_lines;
      int		h;
  
      if (topfrp->fr_win != NULL)
      {
  	/* Simple case: just one window. */
  	win_new_height(topfrp->fr_win,
  				    height - topfrp->fr_win->w_status_height);
      }
  #ifdef FEAT_VERTSPLIT
      else if (topfrp->fr_layout == FR_ROW)
      {
  	do
  	{
  	    /* All frames in this row get the same new height. */
  	    for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
  	    {
  		frame_new_height(frp, height, topfirst, wfh);
  		if (frp->fr_height > height)
  		{
  		    /* Could not fit the windows, make the whole row higher. */
  		    height = frp->fr_height;
  		    break;
  		}
  	    }
  	}
  	while (frp != NULL);
      }
  #endif
      else    /* fr_layout == FR_COL */
      {
  	/* Complicated case: Resize a column of frames.  Resize the bottom
  	 * frame first, frames above that when needed. */
  
  	frp = topfrp->fr_child;
  	if (wfh)
  	    /* Advance past frames with one window with 'wfh' set. */
  	    while (frame_fixed_height(frp))
  	    {
  		frp = frp->fr_next;
  		if (frp == NULL)
  		    return;	    /* no frame without 'wfh', give up */
  	    }
  	if (!topfirst)
  	{
  	    /* Find the bottom frame of this column */
  	    while (frp->fr_next != NULL)
  		frp = frp->fr_next;
  	    if (wfh)
  		/* Advance back for frames with one window with 'wfh' set. */
  		while (frame_fixed_height(frp))
  		    frp = frp->fr_prev;
  	}
  
  	extra_lines = height - topfrp->fr_height;
  	if (extra_lines < 0)
  	{
  	    /* reduce height of contained frames, bottom or top frame first */
  	    while (frp != NULL)
  	    {
  		h = frame_minheight(frp, NULL);
  		if (frp->fr_height + extra_lines < h)
  		{
  		    extra_lines += frp->fr_height - h;
  		    frame_new_height(frp, h, topfirst, wfh);
  		}
  		else
  		{
  		    frame_new_height(frp, frp->fr_height + extra_lines,
  							       topfirst, wfh);
  		    break;
  		}
  		if (topfirst)
  		{
  		    do
  			frp = frp->fr_next;
  		    while (wfh && frp != NULL && frame_fixed_height(frp));
  		}
  		else
  		{
  		    do
  			frp = frp->fr_prev;
  		    while (wfh && frp != NULL && frame_fixed_height(frp));
  		}
  		/* Increase "height" if we could not reduce enough frames. */
  		if (frp == NULL)
  		    height -= extra_lines;
  	    }
  	}
  	else if (extra_lines > 0)
  	{
  	    /* increase height of bottom or top frame */
  	    frame_new_height(frp, frp->fr_height + extra_lines, topfirst, wfh);
  	}
      }
      topfrp->fr_height = height;
  }
  
  /*
   * Return TRUE if height of frame "frp" should not be changed because of
   * the 'winfixheight' option.
   */
      static int
  frame_fixed_height(frp)
      frame_T	*frp;
  {
      /* frame with one window: fixed height if 'winfixheight' set. */
      if (frp->fr_win != NULL)
  	return frp->fr_win->w_p_wfh;
  
      if (frp->fr_layout == FR_ROW)
      {
  	/* The frame is fixed height if one of the frames in the row is fixed
  	 * height. */
  	for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
  	    if (frame_fixed_height(frp))
  		return TRUE;
  	return FALSE;
      }
  
      /* frp->fr_layout == FR_COL: The frame is fixed height if all of the
       * frames in the row are fixed height. */
      for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
  	if (!frame_fixed_height(frp))
  	    return FALSE;
      return TRUE;
  }
  
  #ifdef FEAT_VERTSPLIT
  /*
   * Return TRUE if width of frame "frp" should not be changed because of
   * the 'winfixwidth' option.
   */
      static int
  frame_fixed_width(frp)
      frame_T	*frp;
  {
      /* frame with one window: fixed width if 'winfixwidth' set. */
      if (frp->fr_win != NULL)
  	return frp->fr_win->w_p_wfw;
  
      if (frp->fr_layout == FR_COL)
      {
  	/* The frame is fixed width if one of the frames in the row is fixed
  	 * width. */
  	for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
  	    if (frame_fixed_width(frp))
  		return TRUE;
  	return FALSE;
      }
  
      /* frp->fr_layout == FR_ROW: The frame is fixed width if all of the
       * frames in the row are fixed width. */
      for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
  	if (!frame_fixed_width(frp))
  	    return FALSE;
      return TRUE;
  }
  
  /*
   * Add a status line to windows at the bottom of "frp".
   * Note: Does not check if there is room!
   */
      static void
  frame_add_statusline(frp)
      frame_T	*frp;
  {
      win_T	*wp;
  
      if (frp->fr_layout == FR_LEAF)
      {
  	wp = frp->fr_win;
  	if (wp->w_status_height == 0)
  	{
  	    if (wp->w_height > 0)	/* don't make it negative */
  		--wp->w_height;
  	    wp->w_status_height = STATUS_HEIGHT;
  	}
      }
      else if (frp->fr_layout == FR_ROW)
      {
  	/* Handle all the frames in the row. */
  	for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
  	    frame_add_statusline(frp);
      }
      else /* frp->fr_layout == FR_COL */
      {
  	/* Only need to handle the last frame in the column. */
  	for (frp = frp->fr_child; frp->fr_next != NULL; frp = frp->fr_next)
  	    ;
  	frame_add_statusline(frp);
      }
  }
  
  /*
   * Set width of a frame.  Handles recursively going through contained frames.
   * May remove separator line for windows at the right side (for win_close()).
   */
      static void
  frame_new_width(topfrp, width, leftfirst, wfw)
      frame_T	*topfrp;
      int		width;
      int		leftfirst;	/* resize leftmost contained frame first */
      int		wfw;		/* obey 'winfixwidth' when there is a choice;
  				   may cause the width not to be set */
  {
      frame_T	*frp;
      int		extra_cols;
      int		w;
      win_T	*wp;
  
      if (topfrp->fr_layout == FR_LEAF)
      {
  	/* Simple case: just one window. */
  	wp = topfrp->fr_win;
  	/* Find out if there are any windows right of this one. */
  	for (frp = topfrp; frp->fr_parent != NULL; frp = frp->fr_parent)
  	    if (frp->fr_parent->fr_layout == FR_ROW && frp->fr_next != NULL)
  		break;
  	if (frp->fr_parent == NULL)
  	    wp->w_vsep_width = 0;
  	win_new_width(wp, width - wp->w_vsep_width);
      }
      else if (topfrp->fr_layout == FR_COL)
      {
  	do
  	{
  	    /* All frames in this column get the same new width. */
  	    for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
  	    {
  		frame_new_width(frp, width, leftfirst, wfw);
  		if (frp->fr_width > width)
  		{
  		    /* Could not fit the windows, make whole column wider. */
  		    width = frp->fr_width;
  		    break;
  		}
  	    }
  	} while (frp != NULL);
      }
      else    /* fr_layout == FR_ROW */
      {
  	/* Complicated case: Resize a row of frames.  Resize the rightmost
  	 * frame first, frames left of it when needed. */
  
  	frp = topfrp->fr_child;
  	if (wfw)
  	    /* Advance past frames with one window with 'wfw' set. */
  	    while (frame_fixed_width(frp))
  	    {
  		frp = frp->fr_next;
  		if (frp == NULL)
  		    return;	    /* no frame without 'wfw', give up */
  	    }
  	if (!leftfirst)
  	{
  	    /* Find the rightmost frame of this row */
  	    while (frp->fr_next != NULL)
  		frp = frp->fr_next;
  	    if (wfw)
  		/* Advance back for frames with one window with 'wfw' set. */
  		while (frame_fixed_width(frp))
  		    frp = frp->fr_prev;
  	}
  
  	extra_cols = width - topfrp->fr_width;
  	if (extra_cols < 0)
  	{
  	    /* reduce frame width, rightmost frame first */
  	    while (frp != NULL)
  	    {
  		w = frame_minwidth(frp, NULL);
  		if (frp->fr_width + extra_cols < w)
  		{
  		    extra_cols += frp->fr_width - w;
  		    frame_new_width(frp, w, leftfirst, wfw);
  		}
  		else
  		{
  		    frame_new_width(frp, frp->fr_width + extra_cols,
  							      leftfirst, wfw);
  		    break;
  		}
  		if (leftfirst)
  		{
  		    do
  			frp = frp->fr_next;
  		    while (wfw && frp != NULL && frame_fixed_width(frp));
  		}
  		else
  		{
  		    do
  			frp = frp->fr_prev;
  		    while (wfw && frp != NULL && frame_fixed_width(frp));
  		}
  		/* Increase "width" if we could not reduce enough frames. */
  		if (frp == NULL)
  		    width -= extra_cols;
  	    }
  	}
  	else if (extra_cols > 0)
  	{
  	    /* increase width of rightmost frame */
  	    frame_new_width(frp, frp->fr_width + extra_cols, leftfirst, wfw);
  	}
      }
      topfrp->fr_width = width;
  }
  
  /*
   * Add the vertical separator to windows at the right side of "frp".
   * Note: Does not check if there is room!
   */
      static void
  frame_add_vsep(frp)
      frame_T	*frp;
  {
      win_T	*wp;
  
      if (frp->fr_layout == FR_LEAF)
      {
  	wp = frp->fr_win;
  	if (wp->w_vsep_width == 0)
  	{
  	    if (wp->w_width > 0)	/* don't make it negative */
  		--wp->w_width;
  	    wp->w_vsep_width = 1;
  	}
      }
      else if (frp->fr_layout == FR_COL)
      {
  	/* Handle all the frames in the column. */
  	for (frp = frp->fr_child; frp != NULL; frp = frp->fr_next)
  	    frame_add_vsep(frp);
      }
      else /* frp->fr_layout == FR_ROW */
      {
  	/* Only need to handle the last frame in the row. */
  	frp = frp->fr_child;
  	while (frp->fr_next != NULL)
  	    frp = frp->fr_next;
  	frame_add_vsep(frp);
      }
  }
  
  /*
   * Set frame width from the window it contains.
   */
      static void
  frame_fix_width(wp)
      win_T	*wp;
  {
      wp->w_frame->fr_width = wp->w_width + wp->w_vsep_width;
  }
  #endif
  
  /*
   * Set frame height from the window it contains.
   */
      static void
  frame_fix_height(wp)
      win_T	*wp;
  {
      wp->w_frame->fr_height = wp->w_height + wp->w_status_height;
  }
  
  /*
   * Compute the minimal height for frame "topfrp".
   * Uses the 'winminheight' option.
   * When "next_curwin" isn't NULL, use p_wh for this window.
   * When "next_curwin" is NOWIN, don't use at least one line for the current
   * window.
   */
      static int
  frame_minheight(topfrp, next_curwin)
      frame_T	*topfrp;
      win_T	*next_curwin;
  {
      frame_T	*frp;
      int		m;
  #ifdef FEAT_VERTSPLIT
      int		n;
  #endif
  
      if (topfrp->fr_win != NULL)
      {
  	if (topfrp->fr_win == next_curwin)
  	    m = p_wh + topfrp->fr_win->w_status_height;
  	else
  	{
  	    /* window: minimal height of the window plus status line */
  	    m = p_wmh + topfrp->fr_win->w_status_height;
  	    /* Current window is minimal one line high */
  	    if (p_wmh == 0 && topfrp->fr_win == curwin && next_curwin == NULL)
  		++m;
  	}
      }
  #ifdef FEAT_VERTSPLIT
      else if (topfrp->fr_layout == FR_ROW)
      {
  	/* get the minimal height from each frame in this row */
  	m = 0;
  	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
  	{
  	    n = frame_minheight(frp, next_curwin);
  	    if (n > m)
  		m = n;
  	}
      }
  #endif
      else
      {
  	/* Add up the minimal heights for all frames in this column. */
  	m = 0;
  	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
  	    m += frame_minheight(frp, next_curwin);
      }
  
      return m;
  }
  
  #ifdef FEAT_VERTSPLIT
  /*
   * Compute the minimal width for frame "topfrp".
   * When "next_curwin" isn't NULL, use p_wiw for this window.
   * When "next_curwin" is NOWIN, don't use at least one column for the current
   * window.
   */
      static int
  frame_minwidth(topfrp, next_curwin)
      frame_T	*topfrp;
      win_T	*next_curwin;	/* use p_wh and p_wiw for next_curwin */
  {
      frame_T	*frp;
      int		m, n;
  
      if (topfrp->fr_win != NULL)
      {
  	if (topfrp->fr_win == next_curwin)
  	    m = p_wiw + topfrp->fr_win->w_vsep_width;
  	else
  	{
  	    /* window: minimal width of the window plus separator column */
  	    m = p_wmw + topfrp->fr_win->w_vsep_width;
  	    /* Current window is minimal one column wide */
  	    if (p_wmw == 0 && topfrp->fr_win == curwin && next_curwin == NULL)
  		++m;
  	}
      }
      else if (topfrp->fr_layout == FR_COL)
      {
  	/* get the minimal width from each frame in this column */
  	m = 0;
  	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
  	{
  	    n = frame_minwidth(frp, next_curwin);
  	    if (n > m)
  		m = n;
  	}
      }
      else
      {
  	/* Add up the minimal widths for all frames in this row. */
  	m = 0;
  	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
  	    m += frame_minwidth(frp, next_curwin);
      }
  
      return m;
  }
  #endif
  
  
  /*
   * Try to close all windows except current one.
   * Buffers in the other windows become hidden if 'hidden' is set, or '!' is
   * used and the buffer was modified.
   *
   * Used by ":bdel" and ":only".
   */
      void
  close_others(message, forceit)
      int		message;
      int		forceit;	    /* always hide all other windows */
  {
      win_T	*wp;
      win_T	*nextwp;
      int		r;
  
      if (one_window())
      {
  	if (message
  #ifdef FEAT_AUTOCMD
  		    && !autocmd_busy
  #endif
  				    )
  	    MSG(_(m_onlyone));
  	return;
      }
  
      /* Be very careful here: autocommands may change the window layout. */
      for (wp = firstwin; win_valid(wp); wp = nextwp)
      {
  	nextwp = wp->w_next;
  	if (wp != curwin)		/* don't close current window */
  	{
  
  	    /* Check if it's allowed to abandon this window */
  	    r = can_abandon(wp->w_buffer, forceit);
  #ifdef FEAT_AUTOCMD
  	    if (!win_valid(wp))		/* autocommands messed wp up */
  	    {
  		nextwp = firstwin;
  		continue;
  	    }
  #endif
  	    if (!r)
  	    {
  #if defined(FEAT_GUI_DIALOG) || defined(FEAT_CON_DIALOG)
  		if (message && (p_confirm || cmdmod.confirm) && p_write)
  		{
  		    dialog_changed(wp->w_buffer, FALSE);
  # ifdef FEAT_AUTOCMD
  		    if (!win_valid(wp))		/* autocommands messed wp up */
  		    {
  			nextwp = firstwin;
  			continue;
  		    }
  # endif
  		}
  		if (bufIsChanged(wp->w_buffer))
  #endif
  		    continue;
  	    }
  	    win_close(wp, !P_HID(wp->w_buffer) && !bufIsChanged(wp->w_buffer));
  	}
      }
  
      if (message && lastwin != firstwin)
  	EMSG(_("E445: Other window contains changes"));
  }
  
  #endif /* FEAT_WINDOWS */
  
  /*
   * Init the current window "curwin".
   * Called when a new file is being edited.
   */
      void
  curwin_init()
  {
      win_init_empty(curwin);
  }
  
      void
  win_init_empty(wp)
      win_T *wp;
  {
      redraw_win_later(wp, NOT_VALID);
      wp->w_lines_valid = 0;
      wp->w_cursor.lnum = 1;
      wp->w_curswant = wp->w_cursor.col = 0;
  #ifdef FEAT_VIRTUALEDIT
      wp->w_cursor.coladd = 0;
  #endif
      wp->w_pcmark.lnum = 1;	/* pcmark not cleared but set to line 1 */
      wp->w_pcmark.col = 0;
      wp->w_prev_pcmark.lnum = 0;
      wp->w_prev_pcmark.col = 0;
      wp->w_topline = 1;
  #ifdef FEAT_DIFF
      wp->w_topfill = 0;
  #endif
      wp->w_botline = 2;
  #ifdef FEAT_FKMAP
      if (wp->w_p_rl)
  	wp->w_farsi = W_CONV + W_R_L;
      else
  	wp->w_farsi = W_CONV;
  #endif
  #ifdef FEAT_SYN_HL
      wp->w_s = &wp->w_buffer->b_s;
  #endif
  }
  
  /*
   * Allocate the first window and put an empty buffer in it.
   * Called from main().
   * Return FAIL when something goes wrong (out of memory).
   */
      int
  win_alloc_first()
  {
      if (win_alloc_firstwin(NULL) == FAIL)
  	return FAIL;
  
  #ifdef FEAT_WINDOWS
      first_tabpage = alloc_tabpage();
      if (first_tabpage == NULL)
  	return FAIL;
      first_tabpage->tp_topframe = topframe;
      curtab = first_tabpage;
  #endif
  
      return OK;
  }
  
  #if defined(FEAT_AUTOCMD) || defined(PROTO)
  /*
   * Init "aucmd_win".  This can only be done after the first
   * window is fully initialized, thus it can't be in win_alloc_first().
   */
      void
  win_alloc_aucmd_win()
  {
      aucmd_win = win_alloc(NULL, TRUE);
      if (aucmd_win != NULL)
      {
  	win_init_some(aucmd_win, curwin);
  	RESET_BINDING(aucmd_win);
  	new_frame(aucmd_win);
      }
  }
  #endif
  
  /*
   * Allocate the first window or the first window in a new tab page.
   * When "oldwin" is NULL create an empty buffer for it.
   * When "oldwin" is not NULL copy info from it to the new window (only with
   * FEAT_WINDOWS).
   * Return FAIL when something goes wrong (out of memory).
   */
      static int
  win_alloc_firstwin(oldwin)
      win_T	*oldwin;
  {
      curwin = win_alloc(NULL, FALSE);
      if (oldwin == NULL)
      {
  	/* Very first window, need to create an empty buffer for it and
  	 * initialize from scratch. */
  	curbuf = buflist_new(NULL, NULL, 1L, BLN_LISTED);
  	if (curwin == NULL || curbuf == NULL)
  	    return FAIL;
  	curwin->w_buffer = curbuf;
  #ifdef FEAT_SYN_HL
  	curwin->w_s = &(curbuf->b_s);
  #endif
  	curbuf->b_nwindows = 1;	/* there is one window */
  #ifdef FEAT_WINDOWS
  	curwin->w_alist = &global_alist;
  #endif
  	curwin_init();		/* init current window */
      }
  #ifdef FEAT_WINDOWS
      else
      {
  	/* First window in new tab page, initialize it from "oldwin". */
  	win_init(curwin, oldwin, 0);
  
  	/* We don't want cursor- and scroll-binding in the first window. */
  	RESET_BINDING(curwin);
      }
  #endif
  
      new_frame(curwin);
      if (curwin->w_frame == NULL)
  	return FAIL;
      topframe = curwin->w_frame;
  #ifdef FEAT_VERTSPLIT
      topframe->fr_width = Columns;
  #endif
      topframe->fr_height = Rows - p_ch;
      topframe->fr_win = curwin;
  
      return OK;
  }
  
  /*
   * Create a frame for window "wp".
   */
      static void
  new_frame(win_T *wp)
  {
      frame_T *frp = (frame_T *)alloc_clear((unsigned)sizeof(frame_T));
  
      wp->w_frame = frp;
      if (frp != NULL)
      {
  	frp->fr_layout = FR_LEAF;
  	frp->fr_win = wp;
      }
  }
  
  /*
   * Initialize the window and frame size to the maximum.
   */
      void
  win_init_size()
  {
      firstwin->w_height = ROWS_AVAIL;
      topframe->fr_height = ROWS_AVAIL;
  #ifdef FEAT_VERTSPLIT
      firstwin->w_width = Columns;
      topframe->fr_width = Columns;
  #endif
  }
  
  #if defined(FEAT_WINDOWS) || defined(PROTO)
  
  /*
   * Allocate a new tabpage_T and init the values.
   * Returns NULL when out of memory.
   */
      static tabpage_T *
  alloc_tabpage()
  {
      tabpage_T	*tp;
  # ifdef FEAT_GUI
      int		i;
  # endif
  
  
      tp = (tabpage_T *)alloc_clear((unsigned)sizeof(tabpage_T));
      if (tp == NULL)
  	return NULL;
  
  # ifdef FEAT_EVAL
      /* init t: variables */
      tp->tp_vars = dict_alloc();
      if (tp->tp_vars == NULL)
      {
  	vim_free(tp);
  	return NULL;
      }
      init_var_dict(tp->tp_vars, &tp->tp_winvar, VAR_SCOPE);
  # endif
  
  # ifdef FEAT_GUI
      for (i = 0; i < 3; i++)
  	tp->tp_prev_which_scrollbars[i] = -1;
  # endif
  # ifdef FEAT_DIFF
      tp->tp_diff_invalid = TRUE;
  # endif
      tp->tp_ch_used = p_ch;
  
      return tp;
  }
  
      void
  free_tabpage(tp)
      tabpage_T	*tp;
  {
      int idx;
  
  # ifdef FEAT_DIFF
      diff_clear(tp);
  # endif
      for (idx = 0; idx < SNAP_COUNT; ++idx)
  	clear_snapshot(tp, idx);
  #ifdef FEAT_EVAL
      vars_clear(&tp->tp_vars->dv_hashtab);	/* free all t: variables */
      hash_init(&tp->tp_vars->dv_hashtab);
      unref_var_dict(tp->tp_vars);
  #endif
  
  #ifdef FEAT_PYTHON
      python_tabpage_free(tp);
  #endif
  
  #ifdef FEAT_PYTHON3
      python3_tabpage_free(tp);
  #endif
  
      vim_free(tp);
  }
  
  /*
   * Create a new Tab page with one window.
   * It will edit the current buffer, like after ":split".
   * When "after" is 0 put it just after the current Tab page.
   * Otherwise put it just before tab page "after".
   * Return FAIL or OK.
   */
      int
  win_new_tabpage(after)
      int		after;
  {
      tabpage_T	*tp = curtab;
      tabpage_T	*newtp;
      int		n;
  
      newtp = alloc_tabpage();
      if (newtp == NULL)
  	return FAIL;
  
      /* Remember the current windows in this Tab page. */
      if (leave_tabpage(curbuf, TRUE) == FAIL)
      {
  	vim_free(newtp);
  	return FAIL;
      }
      curtab = newtp;
  
      /* Create a new empty window. */
      if (win_alloc_firstwin(tp->tp_curwin) == OK)
      {
  	/* Make the new Tab page the new topframe. */
  	if (after == 1)
  	{
  	    /* New tab page becomes the first one. */
  	    newtp->tp_next = first_tabpage;
  	    first_tabpage = newtp;
  	}
  	else
  	{
  	    if (after > 0)
  	    {
  		/* Put new tab page before tab page "after". */
  		n = 2;
  		for (tp = first_tabpage; tp->tp_next != NULL
  					       && n < after; tp = tp->tp_next)
  		    ++n;
  	    }
  	    newtp->tp_next = tp->tp_next;
  	    tp->tp_next = newtp;
  	}
  	win_init_size();
  	firstwin->w_winrow = tabline_height();
  	win_comp_scroll(curwin);
  
  	newtp->tp_topframe = topframe;
  	last_status(FALSE);
  
  #if defined(FEAT_GUI)
  	/* When 'guioptions' includes 'L' or 'R' may have to remove or add
  	 * scrollbars.  Have to update them anyway. */
  	gui_may_update_scrollbars();
  #endif
  
  	redraw_all_later(CLEAR);
  #ifdef FEAT_AUTOCMD
  	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
  	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
  #endif
  	return OK;
      }
  
      /* Failed, get back the previous Tab page */
      enter_tabpage(curtab, curbuf, TRUE, TRUE);
      return FAIL;
  }
  
  /*
   * Open a new tab page if ":tab cmd" was used.  It will edit the same buffer,
   * like with ":split".
   * Returns OK if a new tab page was created, FAIL otherwise.
   */
      int
  may_open_tabpage()
  {
      int		n = (cmdmod.tab == 0) ? postponed_split_tab : cmdmod.tab;
  
      if (n != 0)
      {
  	cmdmod.tab = 0;	    /* reset it to avoid doing it twice */
  	postponed_split_tab = 0;
  	return win_new_tabpage(n);
      }
      return FAIL;
  }
  
  /*
   * Create up to "maxcount" tabpages with empty windows.
   * Returns the number of resulting tab pages.
   */
      int
  make_tabpages(maxcount)
      int		maxcount;
  {
      int		count = maxcount;
      int		todo;
  
      /* Limit to 'tabpagemax' tabs. */
      if (count > p_tpm)
  	count = p_tpm;
  
  #ifdef FEAT_AUTOCMD
      /*
       * Don't execute autocommands while creating the tab pages.  Must do that
       * when putting the buffers in the windows.
       */
      block_autocmds();
  #endif
  
      for (todo = count - 1; todo > 0; --todo)
  	if (win_new_tabpage(0) == FAIL)
  	    break;
  
  #ifdef FEAT_AUTOCMD
      unblock_autocmds();
  #endif
  
      /* return actual number of tab pages */
      return (count - todo);
  }
  
  /*
   * Return TRUE when "tpc" points to a valid tab page.
   */
      int
  valid_tabpage(tpc)
      tabpage_T	*tpc;
  {
      tabpage_T	*tp;
  
      for (tp = first_tabpage; tp != NULL; tp = tp->tp_next)
  	if (tp == tpc)
  	    return TRUE;
      return FALSE;
  }
  
  /*
   * Find tab page "n" (first one is 1).  Returns NULL when not found.
   */
      tabpage_T *
  find_tabpage(n)
      int		n;
  {
      tabpage_T	*tp;
      int		i = 1;
  
      for (tp = first_tabpage; tp != NULL && i != n; tp = tp->tp_next)
  	++i;
      return tp;
  }
  
  /*
   * Get index of tab page "tp".  First one has index 1.
   * When not found returns number of tab pages plus one.
   */
      int
  tabpage_index(ftp)
      tabpage_T	*ftp;
  {
      int		i = 1;
      tabpage_T	*tp;
  
      for (tp = first_tabpage; tp != NULL && tp != ftp; tp = tp->tp_next)
  	++i;
      return i;
  }
  
  /*
   * Prepare for leaving the current tab page.
   * When autocommands change "curtab" we don't leave the tab page and return
   * FAIL.
   * Careful: When OK is returned need to get a new tab page very very soon!
   */
      static int
  leave_tabpage(new_curbuf, trigger_leave_autocmds)
      buf_T	*new_curbuf UNUSED;    /* what is going to be the new curbuf,
  				       NULL if unknown */
      int		trigger_leave_autocmds UNUSED;
  {
      tabpage_T	*tp = curtab;
  
  #ifdef FEAT_VISUAL
      reset_VIsual_and_resel();	/* stop Visual mode */
  #endif
  #ifdef FEAT_AUTOCMD
      if (trigger_leave_autocmds)
      {
  	if (new_curbuf != curbuf)
  	{
  	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
  	    if (curtab != tp)
  		return FAIL;
  	}
  	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
  	if (curtab != tp)
  	    return FAIL;
  	apply_autocmds(EVENT_TABLEAVE, NULL, NULL, FALSE, curbuf);
  	if (curtab != tp)
  	    return FAIL;
      }
  #endif
  #if defined(FEAT_GUI)
      /* Remove the scrollbars.  They may be added back later. */
      if (gui.in_use)
  	gui_remove_scrollbars();
  #endif
      tp->tp_curwin = curwin;
      tp->tp_prevwin = prevwin;
      tp->tp_firstwin = firstwin;
      tp->tp_lastwin = lastwin;
      tp->tp_old_Rows = Rows;
      tp->tp_old_Columns = Columns;
      firstwin = NULL;
      lastwin = NULL;
      return OK;
  }
  
  /*
   * Start using tab page "tp".
   * Only to be used after leave_tabpage() or freeing the current tab page.
   * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
   * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
   */
      static void
  enter_tabpage(tp, old_curbuf, trigger_enter_autocmds, trigger_leave_autocmds)
      tabpage_T	*tp;
      buf_T	*old_curbuf UNUSED;
      int		trigger_enter_autocmds UNUSED;
      int		trigger_leave_autocmds UNUSED;
  {
      int		old_off = tp->tp_firstwin->w_winrow;
      win_T	*next_prevwin = tp->tp_prevwin;
  
      curtab = tp;
      firstwin = tp->tp_firstwin;
      lastwin = tp->tp_lastwin;
      topframe = tp->tp_topframe;
  
      /* We would like doing the TabEnter event first, but we don't have a
       * valid current window yet, which may break some commands.
       * This triggers autocommands, thus may make "tp" invalid. */
      win_enter_ext(tp->tp_curwin, FALSE, TRUE,
  			      trigger_enter_autocmds, trigger_leave_autocmds);
      prevwin = next_prevwin;
  
      last_status(FALSE);		/* status line may appear or disappear */
      (void)win_comp_pos();	/* recompute w_winrow for all windows */
      must_redraw = CLEAR;	/* need to redraw everything */
  #ifdef FEAT_DIFF
      diff_need_scrollbind = TRUE;
  #endif
  
      /* The tabpage line may have appeared or disappeared, may need to resize
       * the frames for that.  When the Vim window was resized need to update
       * frame sizes too.  Use the stored value of p_ch, so that it can be
       * different for each tab page. */
      p_ch = curtab->tp_ch_used;
      if (curtab->tp_old_Rows != Rows || (old_off != firstwin->w_winrow
  #ifdef FEAT_GUI_TABLINE
  			    && !gui_use_tabline()
  #endif
  		))
  	shell_new_rows();
  #ifdef FEAT_VERTSPLIT
      if (curtab->tp_old_Columns != Columns && starting == 0)
  	shell_new_columns();	/* update window widths */
  #endif
  
  #if defined(FEAT_GUI)
      /* When 'guioptions' includes 'L' or 'R' may have to remove or add
       * scrollbars.  Have to update them anyway. */
      gui_may_update_scrollbars();
  #endif
  
  #ifdef FEAT_AUTOCMD
      /* Apply autocommands after updating the display, when 'rows' and
       * 'columns' have been set correctly. */
      if (trigger_enter_autocmds)
      {
  	apply_autocmds(EVENT_TABENTER, NULL, NULL, FALSE, curbuf);
  	if (old_curbuf != curbuf)
  	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
      }
  #endif
  
      redraw_all_later(CLEAR);
  }
  
  /*
   * Go to tab page "n".  For ":tab N" and "Ngt".
   * When "n" is 9999 go to the last tab page.
   */
      void
  goto_tabpage(n)
      int	    n;
  {
      tabpage_T	*tp;
      tabpage_T	*ttp;
      int		i;
  
      if (text_locked())
      {
  	/* Not allowed when editing the command line. */
  #ifdef FEAT_CMDWIN
  	if (cmdwin_type != 0)
  	    EMSG(_(e_cmdwin));
  	else
  #endif
  	    EMSG(_(e_secure));
  	return;
      }
  
      /* If there is only one it can't work. */
      if (first_tabpage->tp_next == NULL)
      {
  	if (n > 1)
  	    beep_flush();
  	return;
      }
  
      if (n == 0)
      {
  	/* No count, go to next tab page, wrap around end. */
  	if (curtab->tp_next == NULL)
  	    tp = first_tabpage;
  	else
  	    tp = curtab->tp_next;
      }
      else if (n < 0)
      {
  	/* "gT": go to previous tab page, wrap around end.  "N gT" repeats
  	 * this N times. */
  	ttp = curtab;
  	for (i = n; i < 0; ++i)
  	{
  	    for (tp = first_tabpage; tp->tp_next != ttp && tp->tp_next != NULL;
  		    tp = tp->tp_next)
  		;
  	    ttp = tp;
  	}
      }
      else if (n == 9999)
      {
  	/* Go to last tab page. */
  	for (tp = first_tabpage; tp->tp_next != NULL; tp = tp->tp_next)
  	    ;
      }
      else
      {
  	/* Go to tab page "n". */
  	tp = find_tabpage(n);
  	if (tp == NULL)
  	{
  	    beep_flush();
  	    return;
  	}
      }
  
      goto_tabpage_tp(tp, TRUE, TRUE);
  
  #ifdef FEAT_GUI_TABLINE
      if (gui_use_tabline())
  	gui_mch_set_curtab(tabpage_index(curtab));
  #endif
  }
  
  /*
   * Go to tabpage "tp".
   * Only trigger *Enter autocommands when trigger_enter_autocmds is TRUE.
   * Only trigger *Leave autocommands when trigger_leave_autocmds is TRUE.
   * Note: doesn't update the GUI tab.
   */
      void
  goto_tabpage_tp(tp, trigger_enter_autocmds, trigger_leave_autocmds)
      tabpage_T	*tp;
      int		trigger_enter_autocmds;
      int		trigger_leave_autocmds;
  {
      /* Don't repeat a message in another tab page. */
      set_keep_msg(NULL, 0);
  
      if (tp != curtab && leave_tabpage(tp->tp_curwin->w_buffer,
  					trigger_leave_autocmds) == OK)
      {
  	if (valid_tabpage(tp))
  	    enter_tabpage(tp, curbuf, trigger_enter_autocmds,
  		    trigger_leave_autocmds);
  	else
  	    enter_tabpage(curtab, curbuf, trigger_enter_autocmds,
  		    trigger_leave_autocmds);
      }
  }
  
  /*
   * Enter window "wp" in tab page "tp".
   * Also updates the GUI tab.
   */
      void
  goto_tabpage_win(tp, wp)
      tabpage_T	*tp;
      win_T	*wp;
  {
      goto_tabpage_tp(tp, TRUE, TRUE);
      if (curtab == tp && win_valid(wp))
      {
  	win_enter(wp, TRUE);
  # ifdef FEAT_GUI_TABLINE
  	if (gui_use_tabline())
  	    gui_mch_set_curtab(tabpage_index(curtab));
  # endif
      }
  }
  
  /*
   * Move the current tab page to before tab page "nr".
   */
      void
  tabpage_move(nr)
      int		nr;
  {
      int		n = nr;
      tabpage_T	*tp;
  
      if (first_tabpage->tp_next == NULL)
  	return;
  
      /* Remove the current tab page from the list of tab pages. */
      if (curtab == first_tabpage)
  	first_tabpage = curtab->tp_next;
      else
      {
  	for (tp = first_tabpage; tp != NULL; tp = tp->tp_next)
  	    if (tp->tp_next == curtab)
  		break;
  	if (tp == NULL)	/* "cannot happen" */
  	    return;
  	tp->tp_next = curtab->tp_next;
      }
  
      /* Re-insert it at the specified position. */
      if (n <= 0)
      {
  	curtab->tp_next = first_tabpage;
  	first_tabpage = curtab;
      }
      else
      {
  	for (tp = first_tabpage; tp->tp_next != NULL && n > 1; tp = tp->tp_next)
  	    --n;
  	curtab->tp_next = tp->tp_next;
  	tp->tp_next = curtab;
      }
  
      /* Need to redraw the tabline.  Tab page contents doesn't change. */
      redraw_tabline = TRUE;
  }
  
  
  /*
   * Go to another window.
   * When jumping to another buffer, stop Visual mode.  Do this before
   * changing windows so we can yank the selection into the '*' register.
   * When jumping to another window on the same buffer, adjust its cursor
   * position to keep the same Visual area.
   */
      void
  win_goto(wp)
      win_T	*wp;
  {
  #ifdef FEAT_CONCEAL
      win_T	*owp = curwin;
  #endif
  
      if (text_locked())
      {
  	beep_flush();
  	text_locked_msg();
  	return;
      }
  #ifdef FEAT_AUTOCMD
      if (curbuf_locked())
  	return;
  #endif
  
  #ifdef FEAT_VISUAL
      if (wp->w_buffer != curbuf)
  	reset_VIsual_and_resel();
      else if (VIsual_active)
  	wp->w_cursor = curwin->w_cursor;
  #endif
  
  #ifdef FEAT_GUI
      need_mouse_correct = TRUE;
  #endif
      win_enter(wp, TRUE);
  
  #ifdef FEAT_CONCEAL
      /* Conceal cursor line in previous window, unconceal in current window. */
      if (win_valid(owp) && owp->w_p_cole > 0 && !msg_scrolled)
  	update_single_line(owp, owp->w_cursor.lnum);
      if (curwin->w_p_cole > 0 && !msg_scrolled)
  	need_cursor_line_redraw = TRUE;
  #endif
  }
  
  #if defined(FEAT_PERL) || defined(PROTO)
  /*
   * Find window number "winnr" (counting top to bottom).
   */
      win_T *
  win_find_nr(winnr)
      int		winnr;
  {
      win_T	*wp;
  
  # ifdef FEAT_WINDOWS
      for (wp = firstwin; wp != NULL; wp = wp->w_next)
  	if (--winnr == 0)
  	    break;
      return wp;
  # else
      return curwin;
  # endif
  }
  #endif
  
  #if (defined(FEAT_WINDOWS) && (defined(FEAT_PYTHON) || defined(FEAT_PYTHON3))) \
  	|| defined(PROTO)
  /*
   * Find the tabpage for window "win".
   */
      tabpage_T *
  win_find_tabpage(win)
      win_T	*win;
  {
      win_T	*wp;
      tabpage_T	*tp;
  
      for (tp = first_tabpage; tp != NULL; tp = tp->tp_next)
  	for (wp = (tp == curtab ? firstwin : tp->tp_firstwin);
  						  wp != NULL; wp = wp->w_next)
  	    if (wp == win)
  		return tp;
      return NULL;
  }
  #endif
  
  #ifdef FEAT_VERTSPLIT
  /*
   * Move to window above or below "count" times.
   */
      static void
  win_goto_ver(up, count)
      int		up;		/* TRUE to go to win above */
      long	count;
  {
      frame_T	*fr;
      frame_T	*nfr;
      frame_T	*foundfr;
  
      foundfr = curwin->w_frame;
      while (count--)
      {
  	/*
  	 * First go upwards in the tree of frames until we find a upwards or
  	 * downwards neighbor.
  	 */
  	fr = foundfr;
  	for (;;)
  	{
  	    if (fr == topframe)
  		goto end;
  	    if (up)
  		nfr = fr->fr_prev;
  	    else
  		nfr = fr->fr_next;
  	    if (fr->fr_parent->fr_layout == FR_COL && nfr != NULL)
  		break;
  	    fr = fr->fr_parent;
  	}
  
  	/*
  	 * Now go downwards to find the bottom or top frame in it.
  	 */
  	for (;;)
  	{
  	    if (nfr->fr_layout == FR_LEAF)
  	    {
  		foundfr = nfr;
  		break;
  	    }
  	    fr = nfr->fr_child;
  	    if (nfr->fr_layout == FR_ROW)
  	    {
  		/* Find the frame at the cursor row. */
  		while (fr->fr_next != NULL
  			&& frame2win(fr)->w_wincol + fr->fr_width
  					 <= curwin->w_wincol + curwin->w_wcol)
  		    fr = fr->fr_next;
  	    }
  	    if (nfr->fr_layout == FR_COL && up)
  		while (fr->fr_next != NULL)
  		    fr = fr->fr_next;
  	    nfr = fr;
  	}
      }
  end:
      if (foundfr != NULL)
  	win_goto(foundfr->fr_win);
  }
  
  /*
   * Move to left or right window.
   */
      static void
  win_goto_hor(left, count)
      int		left;		/* TRUE to go to left win */
      long	count;
  {
      frame_T	*fr;
      frame_T	*nfr;
      frame_T	*foundfr;
  
      foundfr = curwin->w_frame;
      while (count--)
      {
  	/*
  	 * First go upwards in the tree of frames until we find a left or
  	 * right neighbor.
  	 */
  	fr = foundfr;
  	for (;;)
  	{
  	    if (fr == topframe)
  		goto end;
  	    if (left)
  		nfr = fr->fr_prev;
  	    else
  		nfr = fr->fr_next;
  	    if (fr->fr_parent->fr_layout == FR_ROW && nfr != NULL)
  		break;
  	    fr = fr->fr_parent;
  	}
  
  	/*
  	 * Now go downwards to find the leftmost or rightmost frame in it.
  	 */
  	for (;;)
  	{
  	    if (nfr->fr_layout == FR_LEAF)
  	    {
  		foundfr = nfr;
  		break;
  	    }
  	    fr = nfr->fr_child;
  	    if (nfr->fr_layout == FR_COL)
  	    {
  		/* Find the frame at the cursor row. */
  		while (fr->fr_next != NULL
  			&& frame2win(fr)->w_winrow + fr->fr_height
  					 <= curwin->w_winrow + curwin->w_wrow)
  		    fr = fr->fr_next;
  	    }
  	    if (nfr->fr_layout == FR_ROW && left)
  		while (fr->fr_next != NULL)
  		    fr = fr->fr_next;
  	    nfr = fr;
  	}
      }
  end:
      if (foundfr != NULL)
  	win_goto(foundfr->fr_win);
  }
  #endif
  
  /*
   * Make window "wp" the current window.
   */
      void
  win_enter(wp, undo_sync)
      win_T	*wp;
      int		undo_sync;
  {
      win_enter_ext(wp, undo_sync, FALSE, TRUE, TRUE);
  }
  
  /*
   * Make window wp the current window.
   * Can be called with "curwin_invalid" TRUE, which means that curwin has just
   * been closed and isn't valid.
   */
      static void
  win_enter_ext(wp, undo_sync, curwin_invalid, trigger_enter_autocmds, trigger_leave_autocmds)
      win_T	*wp;
      int		undo_sync;
      int		curwin_invalid;
      int		trigger_enter_autocmds UNUSED;
      int		trigger_leave_autocmds UNUSED;
  {
  #ifdef FEAT_AUTOCMD
      int		other_buffer = FALSE;
  #endif
  
      if (wp == curwin && !curwin_invalid)	/* nothing to do */
  	return;
  
  #ifdef FEAT_AUTOCMD
      if (!curwin_invalid && trigger_leave_autocmds)
      {
  	/*
  	 * Be careful: If autocommands delete the window, return now.
  	 */
  	if (wp->w_buffer != curbuf)
  	{
  	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
  	    other_buffer = TRUE;
  	    if (!win_valid(wp))
  		return;
  	}
  	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
  	if (!win_valid(wp))
  	    return;
  # ifdef FEAT_EVAL
  	/* autocmds may abort script processing */
  	if (aborting())
  	    return;
  # endif
      }
  #endif
  
      /* sync undo before leaving the current buffer */
      if (undo_sync && curbuf != wp->w_buffer)
  	u_sync(FALSE);
      /* may have to copy the buffer options when 'cpo' contains 'S' */
      if (wp->w_buffer != curbuf)
  	buf_copy_options(wp->w_buffer, BCO_ENTER | BCO_NOHELP);
      if (!curwin_invalid)
      {
  	prevwin = curwin;	/* remember for CTRL-W p */
  	curwin->w_redr_status = TRUE;
      }
      curwin = wp;
      curbuf = wp->w_buffer;
      check_cursor();
  #ifdef FEAT_VIRTUALEDIT
      if (!virtual_active())
  	curwin->w_cursor.coladd = 0;
  #endif
      changed_line_abv_curs();	/* assume cursor position needs updating */
  
      if (curwin->w_localdir != NULL)
      {
  	/* Window has a local directory: Save current directory as global
  	 * directory (unless that was done already) and change to the local
  	 * directory. */
  	if (globaldir == NULL)
  	{
  	    char_u	cwd[MAXPATHL];
  
  	    if (mch_dirname(cwd, MAXPATHL) == OK)
  		globaldir = vim_strsave(cwd);
  	}
  	if (mch_chdir((char *)curwin->w_localdir) == 0)
  	    shorten_fnames(TRUE);
      }
      else if (globaldir != NULL)
      {
  	/* Window doesn't have a local directory and we are not in the global
  	 * directory: Change to the global directory. */
  	ignored = mch_chdir((char *)globaldir);
  	vim_free(globaldir);
  	globaldir = NULL;
  	shorten_fnames(TRUE);
      }
  
  #ifdef FEAT_AUTOCMD
      if (trigger_enter_autocmds)
      {
  	apply_autocmds(EVENT_WINENTER, NULL, NULL, FALSE, curbuf);
  	if (other_buffer)
  	    apply_autocmds(EVENT_BUFENTER, NULL, NULL, FALSE, curbuf);
      }
  #endif
  
  #ifdef FEAT_TITLE
      maketitle();
  #endif
      curwin->w_redr_status = TRUE;
      redraw_tabline = TRUE;
      if (restart_edit)
  	redraw_later(VALID);	/* causes status line redraw */
  
      /* set window height to desired minimal value */
      if (curwin->w_height < p_wh && !curwin->w_p_wfh)
  	win_setheight((int)p_wh);
      else if (curwin->w_height == 0)
  	win_setheight(1);
  
  #ifdef FEAT_VERTSPLIT
      /* set window width to desired minimal value */
      if (curwin->w_width < p_wiw && !curwin->w_p_wfw)
  	win_setwidth((int)p_wiw);
  #endif
  
  #ifdef FEAT_MOUSE
      setmouse();			/* in case jumped to/from help buffer */
  #endif
  
      /* Change directories when the 'acd' option is set. */
      DO_AUTOCHDIR
  }
  
  #endif /* FEAT_WINDOWS */
  
  #if defined(FEAT_WINDOWS) || defined(FEAT_SIGNS) || defined(PROTO)
  /*
   * Jump to the first open window that contains buffer "buf", if one exists.
   * Returns a pointer to the window found, otherwise NULL.
   */
      win_T *
  buf_jump_open_win(buf)
      buf_T	*buf;
  {
  # ifdef FEAT_WINDOWS
      win_T	*wp;
  
      for (wp = firstwin; wp != NULL; wp = wp->w_next)
  	if (wp->w_buffer == buf)
  	    break;
      if (wp != NULL)
  	win_enter(wp, FALSE);
      return wp;
  # else
      if (curwin->w_buffer == buf)
  	return curwin;
      return NULL;
  # endif
  }
  
  /*
   * Jump to the first open window in any tab page that contains buffer "buf",
   * if one exists.
   * Returns a pointer to the window found, otherwise NULL.
   */
      win_T *
  buf_jump_open_tab(buf)
      buf_T	*buf;
  {
  # ifdef FEAT_WINDOWS
      win_T	*wp;
      tabpage_T	*tp;
  
      /* First try the current tab page. */
      wp = buf_jump_open_win(buf);
      if (wp != NULL)
  	return wp;
  
      for (tp = first_tabpage; tp != NULL; tp = tp->tp_next)
  	if (tp != curtab)
  	{
  	    for (wp = tp->tp_firstwin; wp != NULL; wp = wp->w_next)
  		if (wp->w_buffer == buf)
  		    break;
  	    if (wp != NULL)
  	    {
  		goto_tabpage_win(tp, wp);
  		if (curwin != wp)
  		    wp = NULL;	/* something went wrong */
  		break;
  	    }
  	}
  
      return wp;
  # else
      if (curwin->w_buffer == buf)
  	return curwin;
      return NULL;
  # endif
  }
  #endif
  
  /*
   * Allocate a window structure and link it in the window list when "hidden" is
   * FALSE.
   */
      static win_T *
  win_alloc(after, hidden)
      win_T	*after UNUSED;
      int		hidden UNUSED;
  {
      win_T	*new_wp;
  
      /*
       * allocate window structure and linesizes arrays
       */
      new_wp = (win_T *)alloc_clear((unsigned)sizeof(win_T));
      if (new_wp == NULL)
  	return NULL;
  
      if (win_alloc_lines(new_wp) == FAIL)
      {
  	vim_free(new_wp);
  	return NULL;
      }
  
  #ifdef FEAT_EVAL
      /* init w: variables */
      new_wp->w_vars = dict_alloc();
      if (new_wp->w_vars == NULL)
      {
  	win_free_lsize(new_wp);
  	vim_free(new_wp);
  	return NULL;
      }
      init_var_dict(new_wp->w_vars, &new_wp->w_winvar, VAR_SCOPE);
  #endif
  
  #ifdef FEAT_AUTOCMD
      /* Don't execute autocommands while the window is not properly
       * initialized yet.  gui_create_scrollbar() may trigger a FocusGained
       * event. */
      block_autocmds();
  #endif
      /*
       * link the window in the window list
       */
  #ifdef FEAT_WINDOWS
      if (!hidden)
  	win_append(after, new_wp);
  #endif
  #ifdef FEAT_VERTSPLIT
      new_wp->w_wincol = 0;
      new_wp->w_width = Columns;
  #endif
  
      /* position the display and the cursor at the top of the file. */
      new_wp->w_topline = 1;
  #ifdef FEAT_DIFF
      new_wp->w_topfill = 0;
  #endif
      new_wp->w_botline = 2;
      new_wp->w_cursor.lnum = 1;
  #ifdef FEAT_SCROLLBIND
      new_wp->w_scbind_pos = 1;
  #endif
  
      /* We won't calculate w_fraction until resizing the window */
      new_wp->w_fraction = 0;
      new_wp->w_prev_fraction_row = -1;
  
  #ifdef FEAT_GUI
      if (gui.in_use)
      {
  	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_LEFT],
  		SBAR_LEFT, new_wp);
  	gui_create_scrollbar(&new_wp->w_scrollbars[SBAR_RIGHT],
  		SBAR_RIGHT, new_wp);
      }
  #endif
  #ifdef FEAT_FOLDING
      foldInitWin(new_wp);
  #endif
  #ifdef FEAT_AUTOCMD
      unblock_autocmds();
  #endif
  #ifdef FEAT_SEARCH_EXTRA
      new_wp->w_match_head = NULL;
      new_wp->w_next_match_id = 4;
  #endif
      return new_wp;
  }
  
  #if defined(FEAT_WINDOWS) || defined(PROTO)
  
  /*
   * Remove window 'wp' from the window list and free the structure.
   */
      static void
  win_free(wp, tp)
      win_T	*wp;
      tabpage_T	*tp;		/* tab page "win" is in, NULL for current */
  {
      int		i;
      buf_T	*buf;
      wininfo_T	*wip;
  
  #ifdef FEAT_FOLDING
      clearFolding(wp);
  #endif
  
      /* reduce the reference count to the argument list. */
      alist_unlink(wp->w_alist);
  
  #ifdef FEAT_AUTOCMD
      /* Don't execute autocommands while the window is halfway being deleted.
       * gui_mch_destroy_scrollbar() may trigger a FocusGained event. */
      block_autocmds();
  #endif
  
  #ifdef FEAT_LUA
      lua_window_free(wp);
  #endif
  
  #ifdef FEAT_MZSCHEME
      mzscheme_window_free(wp);
  #endif
  
  #ifdef FEAT_PERL
      perl_win_free(wp);
  #endif
  
  #ifdef FEAT_PYTHON
      python_window_free(wp);
  #endif
  
  #ifdef FEAT_PYTHON3
      python3_window_free(wp);
  #endif
  
  #ifdef FEAT_TCL
      tcl_window_free(wp);
  #endif
  
  #ifdef FEAT_RUBY
      ruby_window_free(wp);
  #endif
  
      clear_winopt(&wp->w_onebuf_opt);
      clear_winopt(&wp->w_allbuf_opt);
  
  #ifdef FEAT_EVAL
      vars_clear(&wp->w_vars->dv_hashtab);	/* free all w: variables */
      hash_init(&wp->w_vars->dv_hashtab);
      unref_var_dict(wp->w_vars);
  #endif
  
      if (prevwin == wp)
  	prevwin = NULL;
      win_free_lsize(wp);
  
      for (i = 0; i < wp->w_tagstacklen; ++i)
  	vim_free(wp->w_tagstack[i].tagname);
  
      vim_free(wp->w_localdir);
  
      /* Remove the window from the b_wininfo lists, it may happen that the
       * freed memory is re-used for another window. */
      for (buf = firstbuf; buf != NULL; buf = buf->b_next)
  	for (wip = buf->b_wininfo; wip != NULL; wip = wip->wi_next)
  	    if (wip->wi_win == wp)
  		wip->wi_win = NULL;
  
  #ifdef FEAT_SEARCH_EXTRA
      clear_matches(wp);
  #endif
  
  #ifdef FEAT_JUMPLIST
      free_jumplist(wp);
  #endif
  
  #ifdef FEAT_QUICKFIX
      qf_free_all(wp);
  #endif
  
  #ifdef FEAT_GUI
      if (gui.in_use)
      {
  	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_LEFT]);
  	gui_mch_destroy_scrollbar(&wp->w_scrollbars[SBAR_RIGHT]);
      }
  #endif /* FEAT_GUI */
  
  #ifdef FEAT_SYN_HL
      vim_free(wp->w_p_cc_cols);
  #endif
  
  #ifdef FEAT_AUTOCMD
      if (wp != aucmd_win)
  #endif
  	win_remove(wp, tp);
      vim_free(wp);
  
  #ifdef FEAT_AUTOCMD
      unblock_autocmds();
  #endif
  }
  
  /*
   * Append window "wp" in the window list after window "after".
   */
      void
  win_append(after, wp)
      win_T	*after, *wp;
  {
      win_T	*before;
  
      if (after == NULL)	    /* after NULL is in front of the first */
  	before = firstwin;
      else
  	before = after->w_next;
  
      wp->w_next = before;
      wp->w_prev = after;
      if (after == NULL)
  	firstwin = wp;
      else
  	after->w_next = wp;
      if (before == NULL)
  	lastwin = wp;
      else
  	before->w_prev = wp;
  }
  
  /*
   * Remove a window from the window list.
   */
      void
  win_remove(wp, tp)
      win_T	*wp;
      tabpage_T	*tp;		/* tab page "win" is in, NULL for current */
  {
      if (wp->w_prev != NULL)
  	wp->w_prev->w_next = wp->w_next;
      else if (tp == NULL)
  	firstwin = wp->w_next;
      else
  	tp->tp_firstwin = wp->w_next;
      if (wp->w_next != NULL)
  	wp->w_next->w_prev = wp->w_prev;
      else if (tp == NULL)
  	lastwin = wp->w_prev;
      else
  	tp->tp_lastwin = wp->w_prev;
  }
  
  /*
   * Append frame "frp" in a frame list after frame "after".
   */
      static void
  frame_append(after, frp)
      frame_T	*after, *frp;
  {
      frp->fr_next = after->fr_next;
      after->fr_next = frp;
      if (frp->fr_next != NULL)
  	frp->fr_next->fr_prev = frp;
      frp->fr_prev = after;
  }
  
  /*
   * Insert frame "frp" in a frame list before frame "before".
   */
      static void
  frame_insert(before, frp)
      frame_T	*before, *frp;
  {
      frp->fr_next = before;
      frp->fr_prev = before->fr_prev;
      before->fr_prev = frp;
      if (frp->fr_prev != NULL)
  	frp->fr_prev->fr_next = frp;
      else
  	frp->fr_parent->fr_child = frp;
  }
  
  /*
   * Remove a frame from a frame list.
   */
      static void
  frame_remove(frp)
      frame_T	*frp;
  {
      if (frp->fr_prev != NULL)
  	frp->fr_prev->fr_next = frp->fr_next;
      else
  	frp->fr_parent->fr_child = frp->fr_next;
      if (frp->fr_next != NULL)
  	frp->fr_next->fr_prev = frp->fr_prev;
  }
  
  #endif /* FEAT_WINDOWS */
  
  /*
   * Allocate w_lines[] for window "wp".
   * Return FAIL for failure, OK for success.
   */
      int
  win_alloc_lines(wp)
      win_T	*wp;
  {
      wp->w_lines_valid = 0;
      wp->w_lines = (wline_T *)alloc_clear((unsigned)(Rows * sizeof(wline_T)));
      if (wp->w_lines == NULL)
  	return FAIL;
      return OK;
  }
  
  /*
   * free lsize arrays for a window
   */
      void
  win_free_lsize(wp)
      win_T	*wp;
  {
      vim_free(wp->w_lines);
      wp->w_lines = NULL;
  }
  
  /*
   * Called from win_new_shellsize() after Rows changed.
   * This only does the current tab page, others must be done when made active.
   */
      void
  shell_new_rows()
  {
      int		h = (int)ROWS_AVAIL;
  
      if (firstwin == NULL)	/* not initialized yet */
  	return;
  #ifdef FEAT_WINDOWS
      if (h < frame_minheight(topframe, NULL))
  	h = frame_minheight(topframe, NULL);
  
      /* First try setting the heights of windows with 'winfixheight'.  If
       * that doesn't result in the right height, forget about that option. */
      frame_new_height(topframe, h, FALSE, TRUE);
      if (!frame_check_height(topframe, h))
  	frame_new_height(topframe, h, FALSE, FALSE);
  
      (void)win_comp_pos();		/* recompute w_winrow and w_wincol */
  #else
      if (h < 1)
  	h = 1;
      win_new_height(firstwin, h);
  #endif
      compute_cmdrow();
  #ifdef FEAT_WINDOWS
      curtab->tp_ch_used = p_ch;
  #endif
  
  #if 0
      /* Disabled: don't want making the screen smaller make a window larger. */
      if (p_ea)
  	win_equal(curwin, FALSE, 'v');
  #endif
  }
  
  #if defined(FEAT_VERTSPLIT) || defined(PROTO)
  /*
   * Called from win_new_shellsize() after Columns changed.
   */
      void
  shell_new_columns()
  {
      if (firstwin == NULL)	/* not initialized yet */
  	return;
  
      /* First try setting the widths of windows with 'winfixwidth'.  If that
       * doesn't result in the right width, forget about that option. */
      frame_new_width(topframe, (int)Columns, FALSE, TRUE);
      if (!frame_check_width(topframe, Columns))
  	frame_new_width(topframe, (int)Columns, FALSE, FALSE);
  
      (void)win_comp_pos();		/* recompute w_winrow and w_wincol */
  #if 0
      /* Disabled: don't want making the screen smaller make a window larger. */
      if (p_ea)
  	win_equal(curwin, FALSE, 'h');
  #endif
  }
  #endif
  
  #if defined(FEAT_CMDWIN) || defined(PROTO)
  /*
   * Save the size of all windows in "gap".
   */
      void
  win_size_save(gap)
      garray_T	*gap;
  
  {
      win_T	*wp;
  
      ga_init2(gap, (int)sizeof(int), 1);
      if (ga_grow(gap, win_count() * 2) == OK)
  	for (wp = firstwin; wp != NULL; wp = wp->w_next)
  	{
  	    ((int *)gap->ga_data)[gap->ga_len++] =
  					       wp->w_width + wp->w_vsep_width;
  	    ((int *)gap->ga_data)[gap->ga_len++] = wp->w_height;
  	}
  }
  
  /*
   * Restore window sizes, but only if the number of windows is still the same.
   * Does not free the growarray.
   */
      void
  win_size_restore(gap)
      garray_T	*gap;
  {
      win_T	*wp;
      int		i;
  
      if (win_count() * 2 == gap->ga_len)
      {
  	i = 0;
  	for (wp = firstwin; wp != NULL; wp = wp->w_next)
  	{
  	    frame_setwidth(wp->w_frame, ((int *)gap->ga_data)[i++]);
  	    win_setheight_win(((int *)gap->ga_data)[i++], wp);
  	}
  	/* recompute the window positions */
  	(void)win_comp_pos();
      }
  }
  #endif /* FEAT_CMDWIN */
  
  #if defined(FEAT_WINDOWS) || defined(PROTO)
  /*
   * Update the position for all windows, using the width and height of the
   * frames.
   * Returns the row just after the last window.
   */
      int
  win_comp_pos()
  {
      int		row = tabline_height();
      int		col = 0;
  
      frame_comp_pos(topframe, &row, &col);
      return row;
  }
  
  /*
   * Update the position of the windows in frame "topfrp", using the width and
   * height of the frames.
   * "*row" and "*col" are the top-left position of the frame.  They are updated
   * to the bottom-right position plus one.
   */
      static void
  frame_comp_pos(topfrp, row, col)
      frame_T	*topfrp;
      int		*row;
      int		*col;
  {
      win_T	*wp;
      frame_T	*frp;
  #ifdef FEAT_VERTSPLIT
      int		startcol;
      int		startrow;
  #endif
  
      wp = topfrp->fr_win;
      if (wp != NULL)
      {
  	if (wp->w_winrow != *row
  #ifdef FEAT_VERTSPLIT
  		|| wp->w_wincol != *col
  #endif
  		)
  	{
  	    /* position changed, redraw */
  	    wp->w_winrow = *row;
  #ifdef FEAT_VERTSPLIT
  	    wp->w_wincol = *col;
  #endif
  	    redraw_win_later(wp, NOT_VALID);
  	    wp->w_redr_status = TRUE;
  	}
  	*row += wp->w_height + wp->w_status_height;
  #ifdef FEAT_VERTSPLIT
  	*col += wp->w_width + wp->w_vsep_width;
  #endif
      }
      else
      {
  #ifdef FEAT_VERTSPLIT
  	startrow = *row;
  	startcol = *col;
  #endif
  	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
  	{
  #ifdef FEAT_VERTSPLIT
  	    if (topfrp->fr_layout == FR_ROW)
  		*row = startrow;	/* all frames are at the same row */
  	    else
  		*col = startcol;	/* all frames are at the same col */
  #endif
  	    frame_comp_pos(frp, row, col);
  	}
      }
  }
  
  #endif /* FEAT_WINDOWS */
  
  /*
   * Set current window height and take care of repositioning other windows to
   * fit around it.
   */
      void
  win_setheight(height)
      int		height;
  {
      win_setheight_win(height, curwin);
  }
  
  /*
   * Set the window height of window "win" and take care of repositioning other
   * windows to fit around it.
   */
      void
  win_setheight_win(height, win)
      int		height;
      win_T	*win;
  {
      int		row;
  
      if (win == curwin)
      {
  	/* Always keep current window at least one line high, even when
  	 * 'winminheight' is zero. */
  #ifdef FEAT_WINDOWS
  	if (height < p_wmh)
  	    height = p_wmh;
  #endif
  	if (height == 0)
  	    height = 1;
      }
  
  #ifdef FEAT_WINDOWS
      frame_setheight(win->w_frame, height + win->w_status_height);
  
      /* recompute the window positions */
      row = win_comp_pos();
  #else
      if (height > topframe->fr_height)
  	height = topframe->fr_height;
      win->w_height = height;
      row = height;
  #endif
  
      /*
       * If there is extra space created between the last window and the command
       * line, clear it.
       */
      if (full_screen && msg_scrolled == 0 && row < cmdline_row)
  	screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
      cmdline_row = row;
      msg_row = row;
      msg_col = 0;
  
      redraw_all_later(NOT_VALID);
  }
  
  #if defined(FEAT_WINDOWS) || defined(PROTO)
  
  /*
   * Set the height of a frame to "height" and take care that all frames and
   * windows inside it are resized.  Also resize frames on the left and right if
   * the are in the same FR_ROW frame.
   *
   * Strategy:
   * If the frame is part of a FR_COL frame, try fitting the frame in that
   * frame.  If that doesn't work (the FR_COL frame is too small), recursively
   * go to containing frames to resize them and make room.
   * If the frame is part of a FR_ROW frame, all frames must be resized as well.
   * Check for the minimal height of the FR_ROW frame.
   * At the top level we can also use change the command line height.
   */
      static void
  frame_setheight(curfrp, height)
      frame_T	*curfrp;
      int		height;
  {
      int		room;		/* total number of lines available */
      int		take;		/* number of lines taken from other windows */
      int		room_cmdline;	/* lines available from cmdline */
      int		run;
      frame_T	*frp;
      int		h;
      int		room_reserved;
  
      /* If the height already is the desired value, nothing to do. */
      if (curfrp->fr_height == height)
  	return;
  
      if (curfrp->fr_parent == NULL)
      {
  	/* topframe: can only change the command line */
  	if (height > ROWS_AVAIL)
  	    height = ROWS_AVAIL;
  	if (height > 0)
  	    frame_new_height(curfrp, height, FALSE, FALSE);
      }
      else if (curfrp->fr_parent->fr_layout == FR_ROW)
      {
  	/* Row of frames: Also need to resize frames left and right of this
  	 * one.  First check for the minimal height of these. */
  	h = frame_minheight(curfrp->fr_parent, NULL);
  	if (height < h)
  	    height = h;
  	frame_setheight(curfrp->fr_parent, height);
      }
      else
      {
  	/*
  	 * Column of frames: try to change only frames in this column.
  	 */
  #ifdef FEAT_VERTSPLIT
  	/*
  	 * Do this twice:
  	 * 1: compute room available, if it's not enough try resizing the
  	 *    containing frame.
  	 * 2: compute the room available and adjust the height to it.
  	 * Try not to reduce the height of a window with 'winfixheight' set.
  	 */
  	for (run = 1; run <= 2; ++run)
  #else
  	for (;;)
  #endif
  	{
  	    room = 0;
  	    room_reserved = 0;
  	    for (frp = curfrp->fr_parent->fr_child; frp != NULL;
  							   frp = frp->fr_next)
  	    {
  		if (frp != curfrp
  			&& frp->fr_win != NULL
  			&& frp->fr_win->w_p_wfh)
  		    room_reserved += frp->fr_height;
  		room += frp->fr_height;
  		if (frp != curfrp)
  		    room -= frame_minheight(frp, NULL);
  	    }
  #ifdef FEAT_VERTSPLIT
  	    if (curfrp->fr_width != Columns)
  		room_cmdline = 0;
  	    else
  #endif
  	    {
  		room_cmdline = Rows - p_ch - (lastwin->w_winrow
  			       + lastwin->w_height + lastwin->w_status_height);
  		if (room_cmdline < 0)
  		    room_cmdline = 0;
  	    }
  
  	    if (height <= room + room_cmdline)
  		break;
  #ifdef FEAT_VERTSPLIT
  	    if (run == 2 || curfrp->fr_width == Columns)
  #endif
  	    {
  		if (height > room + room_cmdline)
  		    height = room + room_cmdline;
  		break;
  	    }
  #ifdef FEAT_VERTSPLIT
  	    frame_setheight(curfrp->fr_parent, height
  		+ frame_minheight(curfrp->fr_parent, NOWIN) - (int)p_wmh - 1);
  #endif
  	    /*NOTREACHED*/
  	}
  
  	/*
  	 * Compute the number of lines we will take from others frames (can be
  	 * negative!).
  	 */
  	take = height - curfrp->fr_height;
  
  	/* If there is not enough room, also reduce the height of a window
  	 * with 'winfixheight' set. */
  	if (height > room + room_cmdline - room_reserved)
  	    room_reserved = room + room_cmdline - height;
  	/* If there is only a 'winfixheight' window and making the
  	 * window smaller, need to make the other window taller. */
  	if (take < 0 && room - curfrp->fr_height < room_reserved)
  	    room_reserved = 0;
  
  	if (take > 0 && room_cmdline > 0)
  	{
  	    /* use lines from cmdline first */
  	    if (take < room_cmdline)
  		room_cmdline = take;
  	    take -= room_cmdline;
  	    topframe->fr_height += room_cmdline;
  	}
  
  	/*
  	 * set the current frame to the new height
  	 */
  	frame_new_height(curfrp, height, FALSE, FALSE);
  
  	/*
  	 * First take lines from the frames after the current frame.  If
  	 * that is not enough, takes lines from frames above the current
  	 * frame.
  	 */
  	for (run = 0; run < 2; ++run)
  	{
  	    if (run == 0)
  		frp = curfrp->fr_next;	/* 1st run: start with next window */
  	    else
  		frp = curfrp->fr_prev;	/* 2nd run: start with prev window */
  	    while (frp != NULL && take != 0)
  	    {
  		h = frame_minheight(frp, NULL);
  		if (room_reserved > 0
  			&& frp->fr_win != NULL
  			&& frp->fr_win->w_p_wfh)
  		{
  		    if (room_reserved >= frp->fr_height)
  			room_reserved -= frp->fr_height;
  		    else
  		    {
  			if (frp->fr_height - room_reserved > take)
  			    room_reserved = frp->fr_height - take;
  			take -= frp->fr_height - room_reserved;
  			frame_new_height(frp, room_reserved, FALSE, FALSE);
  			room_reserved = 0;
  		    }
  		}
  		else
  		{
  		    if (frp->fr_height - take < h)
  		    {
  			take -= frp->fr_height - h;
  			frame_new_height(frp, h, FALSE, FALSE);
  		    }
  		    else
  		    {
  			frame_new_height(frp, frp->fr_height - take,
  								FALSE, FALSE);
  			take = 0;
  		    }
  		}
  		if (run == 0)
  		    frp = frp->fr_next;
  		else
  		    frp = frp->fr_prev;
  	    }
  	}
      }
  }
  
  #if defined(FEAT_VERTSPLIT) || defined(PROTO)
  /*
   * Set current window width and take care of repositioning other windows to
   * fit around it.
   */
      void
  win_setwidth(width)
      int		width;
  {
      win_setwidth_win(width, curwin);
  }
  
      void
  win_setwidth_win(width, wp)
      int		width;
      win_T	*wp;
  {
      /* Always keep current window at least one column wide, even when
       * 'winminwidth' is zero. */
      if (wp == curwin)
      {
  	if (width < p_wmw)
  	    width = p_wmw;
  	if (width == 0)
  	    width = 1;
      }
  
      frame_setwidth(wp->w_frame, width + wp->w_vsep_width);
  
      /* recompute the window positions */
      (void)win_comp_pos();
  
      redraw_all_later(NOT_VALID);
  }
  
  /*
   * Set the width of a frame to "width" and take care that all frames and
   * windows inside it are resized.  Also resize frames above and below if the
   * are in the same FR_ROW frame.
   *
   * Strategy is similar to frame_setheight().
   */
      static void
  frame_setwidth(curfrp, width)
      frame_T	*curfrp;
      int		width;
  {
      int		room;		/* total number of lines available */
      int		take;		/* number of lines taken from other windows */
      int		run;
      frame_T	*frp;
      int		w;
      int		room_reserved;
  
      /* If the width already is the desired value, nothing to do. */
      if (curfrp->fr_width == width)
  	return;
  
      if (curfrp->fr_parent == NULL)
  	/* topframe: can't change width */
  	return;
  
      if (curfrp->fr_parent->fr_layout == FR_COL)
      {
  	/* Column of frames: Also need to resize frames above and below of
  	 * this one.  First check for the minimal width of these. */
  	w = frame_minwidth(curfrp->fr_parent, NULL);
  	if (width < w)
  	    width = w;
  	frame_setwidth(curfrp->fr_parent, width);
      }
      else
      {
  	/*
  	 * Row of frames: try to change only frames in this row.
  	 *
  	 * Do this twice:
  	 * 1: compute room available, if it's not enough try resizing the
  	 *    containing frame.
  	 * 2: compute the room available and adjust the width to it.
  	 */
  	for (run = 1; run <= 2; ++run)
  	{
  	    room = 0;
  	    room_reserved = 0;
  	    for (frp = curfrp->fr_parent->fr_child; frp != NULL;
  							   frp = frp->fr_next)
  	    {
  		if (frp != curfrp
  			&& frp->fr_win != NULL
  			&& frp->fr_win->w_p_wfw)
  		    room_reserved += frp->fr_width;
  		room += frp->fr_width;
  		if (frp != curfrp)
  		    room -= frame_minwidth(frp, NULL);
  	    }
  
  	    if (width <= room)
  		break;
  	    if (run == 2 || curfrp->fr_height >= ROWS_AVAIL)
  	    {
  		if (width > room)
  		    width = room;
  		break;
  	    }
  	    frame_setwidth(curfrp->fr_parent, width
  		 + frame_minwidth(curfrp->fr_parent, NOWIN) - (int)p_wmw - 1);
  	}
  
  	/*
  	 * Compute the number of lines we will take from others frames (can be
  	 * negative!).
  	 */
  	take = width - curfrp->fr_width;
  
  	/* If there is not enough room, also reduce the width of a window
  	 * with 'winfixwidth' set. */
  	if (width > room - room_reserved)
  	    room_reserved = room - width;
  	/* If there is only a 'winfixwidth' window and making the
  	 * window smaller, need to make the other window narrower. */
  	if (take < 0 && room - curfrp->fr_width < room_reserved)
  	    room_reserved = 0;
  
  	/*
  	 * set the current frame to the new width
  	 */
  	frame_new_width(curfrp, width, FALSE, FALSE);
  
  	/*
  	 * First take lines from the frames right of the current frame.  If
  	 * that is not enough, takes lines from frames left of the current
  	 * frame.
  	 */
  	for (run = 0; run < 2; ++run)
  	{
  	    if (run == 0)
  		frp = curfrp->fr_next;	/* 1st run: start with next window */
  	    else
  		frp = curfrp->fr_prev;	/* 2nd run: start with prev window */
  	    while (frp != NULL && take != 0)
  	    {
  		w = frame_minwidth(frp, NULL);
  		if (room_reserved > 0
  			&& frp->fr_win != NULL
  			&& frp->fr_win->w_p_wfw)
  		{
  		    if (room_reserved >= frp->fr_width)
  			room_reserved -= frp->fr_width;
  		    else
  		    {
  			if (frp->fr_width - room_reserved > take)
  			    room_reserved = frp->fr_width - take;
  			take -= frp->fr_width - room_reserved;
  			frame_new_width(frp, room_reserved, FALSE, FALSE);
  			room_reserved = 0;
  		    }
  		}
  		else
  		{
  		    if (frp->fr_width - take < w)
  		    {
  			take -= frp->fr_width - w;
  			frame_new_width(frp, w, FALSE, FALSE);
  		    }
  		    else
  		    {
  			frame_new_width(frp, frp->fr_width - take,
  								FALSE, FALSE);
  			take = 0;
  		    }
  		}
  		if (run == 0)
  		    frp = frp->fr_next;
  		else
  		    frp = frp->fr_prev;
  	    }
  	}
      }
  }
  #endif /* FEAT_VERTSPLIT */
  
  /*
   * Check 'winminheight' for a valid value.
   */
      void
  win_setminheight()
  {
      int		room;
      int		first = TRUE;
      win_T	*wp;
  
      /* loop until there is a 'winminheight' that is possible */
      while (p_wmh > 0)
      {
  	/* TODO: handle vertical splits */
  	room = -p_wh;
  	for (wp = firstwin; wp != NULL; wp = wp->w_next)
  	    room += wp->w_height - p_wmh;
  	if (room >= 0)
  	    break;
  	--p_wmh;
  	if (first)
  	{
  	    EMSG(_(e_noroom));
  	    first = FALSE;
  	}
      }
  }
  
  #ifdef FEAT_MOUSE
  
  /*
   * Status line of dragwin is dragged "offset" lines down (negative is up).
   */
      void
  win_drag_status_line(dragwin, offset)
      win_T	*dragwin;
      int		offset;
  {
      frame_T	*curfr;
      frame_T	*fr;
      int		room;
      int		row;
      int		up;	/* if TRUE, drag status line up, otherwise down */
      int		n;
  
      fr = dragwin->w_frame;
      curfr = fr;
      if (fr != topframe)		/* more than one window */
      {
  	fr = fr->fr_parent;
  	/* When the parent frame is not a column of frames, its parent should
  	 * be. */
  	if (fr->fr_layout != FR_COL)
  	{
  	    curfr = fr;
  	    if (fr != topframe)	/* only a row of windows, may drag statusline */
  		fr = fr->fr_parent;
  	}
      }
  
      /* If this is the last frame in a column, may want to resize the parent
       * frame instead (go two up to skip a row of frames). */
      while (curfr != topframe && curfr->fr_next == NULL)
      {
  	if (fr != topframe)
  	    fr = fr->fr_parent;
  	curfr = fr;
  	if (fr != topframe)
  	    fr = fr->fr_parent;
      }
  
      if (offset < 0) /* drag up */
      {
  	up = TRUE;
  	offset = -offset;
  	/* sum up the room of the current frame and above it */
  	if (fr == curfr)
  	{
  	    /* only one window */
  	    room = fr->fr_height - frame_minheight(fr, NULL);
  	}
  	else
  	{
  	    room = 0;
  	    for (fr = fr->fr_child; ; fr = fr->fr_next)
  	    {
  		room += fr->fr_height - frame_minheight(fr, NULL);
  		if (fr == curfr)
  		    break;
  	    }
  	}
  	fr = curfr->fr_next;		/* put fr at frame that grows */
      }
      else    /* drag down */
      {
  	up = FALSE;
  	/*
  	 * Only dragging the last status line can reduce p_ch.
  	 */
  	room = Rows - cmdline_row;
  	if (curfr->fr_next == NULL)
  	    room -= 1;
  	else
  	    room -= p_ch;
  	if (room < 0)
  	    room = 0;
  	/* sum up the room of frames below of the current one */
  	for (fr = curfr->fr_next; fr != NULL; fr = fr->fr_next)
  	    room += fr->fr_height - frame_minheight(fr, NULL);
  	fr = curfr;			/* put fr at window that grows */
      }
  
      if (room < offset)		/* Not enough room */
  	offset = room;		/* Move as far as we can */
      if (offset <= 0)
  	return;
  
      /*
       * Grow frame fr by "offset" lines.
       * Doesn't happen when dragging the last status line up.
       */
      if (fr != NULL)
  	frame_new_height(fr, fr->fr_height + offset, up, FALSE);
  
      if (up)
  	fr = curfr;		/* current frame gets smaller */
      else
  	fr = curfr->fr_next;	/* next frame gets smaller */
  
      /*
       * Now make the other frames smaller.
       */
      while (fr != NULL && offset > 0)
      {
  	n = frame_minheight(fr, NULL);
  	if (fr->fr_height - offset <= n)
  	{
  	    offset -= fr->fr_height - n;
  	    frame_new_height(fr, n, !up, FALSE);
  	}
  	else
  	{
  	    frame_new_height(fr, fr->fr_height - offset, !up, FALSE);
  	    break;
  	}
  	if (up)
  	    fr = fr->fr_prev;
  	else
  	    fr = fr->fr_next;
      }
      row = win_comp_pos();
      screen_fill(row, cmdline_row, 0, (int)Columns, ' ', ' ', 0);
      cmdline_row = row;
      p_ch = Rows - cmdline_row;
      if (p_ch < 1)
  	p_ch = 1;
      curtab->tp_ch_used = p_ch;
      redraw_all_later(SOME_VALID);
      showmode();
  }
  
  #ifdef FEAT_VERTSPLIT
  /*
   * Separator line of dragwin is dragged "offset" lines right (negative is left).
   */
      void
  win_drag_vsep_line(dragwin, offset)
      win_T	*dragwin;
      int		offset;
  {
      frame_T	*curfr;
      frame_T	*fr;
      int		room;
      int		left;	/* if TRUE, drag separator line left, otherwise right */
      int		n;
  
      fr = dragwin->w_frame;
      if (fr == topframe)		/* only one window (cannot happen?) */
  	return;
      curfr = fr;
      fr = fr->fr_parent;
      /* When the parent frame is not a row of frames, its parent should be. */
      if (fr->fr_layout != FR_ROW)
      {
  	if (fr == topframe)	/* only a column of windows (cannot happen?) */
  	    return;
  	curfr = fr;
  	fr = fr->fr_parent;
      }
  
      /* If this is the last frame in a row, may want to resize a parent
       * frame instead. */
      while (curfr->fr_next == NULL)
      {
  	if (fr == topframe)
  	    break;
  	curfr = fr;
  	fr = fr->fr_parent;
  	if (fr != topframe)
  	{
  	    curfr = fr;
  	    fr = fr->fr_parent;
  	}
      }
  
      if (offset < 0) /* drag left */
      {
  	left = TRUE;
  	offset = -offset;
  	/* sum up the room of the current frame and left of it */
  	room = 0;
  	for (fr = fr->fr_child; ; fr = fr->fr_next)
  	{
  	    room += fr->fr_width - frame_minwidth(fr, NULL);
  	    if (fr == curfr)
  		break;
  	}
  	fr = curfr->fr_next;		/* put fr at frame that grows */
      }
      else    /* drag right */
      {
  	left = FALSE;
  	/* sum up the room of frames right of the current one */
  	room = 0;
  	for (fr = curfr->fr_next; fr != NULL; fr = fr->fr_next)
  	    room += fr->fr_width - frame_minwidth(fr, NULL);
  	fr = curfr;			/* put fr at window that grows */
      }
  
      if (room < offset)		/* Not enough room */
  	offset = room;		/* Move as far as we can */
      if (offset <= 0)		/* No room at all, quit. */
  	return;
  
      /* grow frame fr by offset lines */
      frame_new_width(fr, fr->fr_width + offset, left, FALSE);
  
      /* shrink other frames: current and at the left or at the right */
      if (left)
  	fr = curfr;		/* current frame gets smaller */
      else
  	fr = curfr->fr_next;	/* next frame gets smaller */
  
      while (fr != NULL && offset > 0)
      {
  	n = frame_minwidth(fr, NULL);
  	if (fr->fr_width - offset <= n)
  	{
  	    offset -= fr->fr_width - n;
  	    frame_new_width(fr, n, !left, FALSE);
  	}
  	else
  	{
  	    frame_new_width(fr, fr->fr_width - offset, !left, FALSE);
  	    break;
  	}
  	if (left)
  	    fr = fr->fr_prev;
  	else
  	    fr = fr->fr_next;
      }
      (void)win_comp_pos();
      redraw_all_later(NOT_VALID);
  }
  #endif /* FEAT_VERTSPLIT */
  #endif /* FEAT_MOUSE */
  
  #endif /* FEAT_WINDOWS */
  
  #define FRACTION_MULT	16384L
  
  /*
   * Set wp->w_fraction for the current w_wrow and w_height.
   */
      static void
  set_fraction(wp)
      win_T	*wp;
  {
      wp->w_fraction = ((long)wp->w_wrow * FRACTION_MULT
  				    + FRACTION_MULT / 2) / (long)wp->w_height;
  }
  
  /*
   * Set the height of a window.
   * This takes care of the things inside the window, not what happens to the
   * window position, the frame or to other windows.
   */
      void
  win_new_height(wp, height)
      win_T	*wp;
      int		height;
  {
      linenr_T	lnum;
      int		sline, line_size;
  
      /* Don't want a negative height.  Happens when splitting a tiny window.
       * Will equalize heights soon to fix it. */
      if (height < 0)
  	height = 0;
      if (wp->w_height == height)
  	return;	    /* nothing to do */
  
      if (wp->w_wrow != wp->w_prev_fraction_row && wp->w_height > 0)
  	set_fraction(wp);
  
      wp->w_height = height;
      wp->w_skipcol = 0;
  
      /* Don't change w_topline when height is zero.  Don't set w_topline when
       * 'scrollbind' is set and this isn't the current window. */
      if (height > 0
  #ifdef FEAT_SCROLLBIND
  	    && (!wp->w_p_scb || wp == curwin)
  #endif
         )
      {
  	/*
  	 * Find a value for w_topline that shows the cursor at the same
  	 * relative position in the window as before (more or less).
  	 */
  	lnum = wp->w_cursor.lnum;
  	if (lnum < 1)		/* can happen when starting up */
  	    lnum = 1;
  	wp->w_wrow = ((long)wp->w_fraction * (long)height - 1L) / FRACTION_MULT;
  	line_size = plines_win_col(wp, lnum, (long)(wp->w_cursor.col)) - 1;
  	sline = wp->w_wrow - line_size;
  
  	if (sline >= 0)
  	{
  	    /* Make sure the whole cursor line is visible, if possible. */
  	    int rows = plines_win(wp, lnum, FALSE);
  
  	    if (sline > wp->w_height - rows)
  	    {
  		sline = wp->w_height - rows;
  		wp->w_wrow -= rows - line_size;
  	    }
  	}
  
  	if (sline < 0)
  	{
  	    /*
  	     * Cursor line would go off top of screen if w_wrow was this high.
  	     * Make cursor line the first line in the window.  If not enough
  	     * room use w_skipcol;
  	     */
  	    wp->w_wrow = line_size;
  	    if (wp->w_wrow >= wp->w_height
  				       && (W_WIDTH(wp) - win_col_off(wp)) > 0)
  	    {
  		wp->w_skipcol += W_WIDTH(wp) - win_col_off(wp);
  		--wp->w_wrow;
  		while (wp->w_wrow >= wp->w_height)
  		{
  		    wp->w_skipcol += W_WIDTH(wp) - win_col_off(wp)
  							   + win_col_off2(wp);
  		    --wp->w_wrow;
  		}
  	    }
  	}
  	else
  	{
  	    while (sline > 0 && lnum > 1)
  	    {
  #ifdef FEAT_FOLDING
  		hasFoldingWin(wp, lnum, &lnum, NULL, TRUE, NULL);
  		if (lnum == 1)
  		{
  		    /* first line in buffer is folded */
  		    line_size = 1;
  		    --sline;
  		    break;
  		}
  #endif
  		--lnum;
  #ifdef FEAT_DIFF
  		if (lnum == wp->w_topline)
  		    line_size = plines_win_nofill(wp, lnum, TRUE)
  							      + wp->w_topfill;
  		else
  #endif
  		    line_size = plines_win(wp, lnum, TRUE);
  		sline -= line_size;
  	    }
  
  	    if (sline < 0)
  	    {
  		/*
  		 * Line we want at top would go off top of screen.  Use next
  		 * line instead.
  		 */
  #ifdef FEAT_FOLDING
  		hasFoldingWin(wp, lnum, NULL, &lnum, TRUE, NULL);
  #endif
  		lnum++;
  		wp->w_wrow -= line_size + sline;
  	    }
  	    else if (sline > 0)
  	    {
  		/* First line of file reached, use that as topline. */
  		lnum = 1;
  		wp->w_wrow -= sline;
  	    }
  	}
  	set_topline(wp, lnum);
      }
  
      if (wp == curwin)
      {
  	if (p_so)
  	    update_topline();
  	curs_columns(FALSE);	/* validate w_wrow */
      }
      wp->w_prev_fraction_row = wp->w_wrow;
  
      win_comp_scroll(wp);
      redraw_win_later(wp, SOME_VALID);
  #ifdef FEAT_WINDOWS
      wp->w_redr_status = TRUE;
  #endif
      invalidate_botline_win(wp);
  }
  
  #ifdef FEAT_VERTSPLIT
  /*
   * Set the width of a window.
   */
      void
  win_new_width(wp, width)
      win_T	*wp;
      int		width;
  {
      wp->w_width = width;
      wp->w_lines_valid = 0;
      changed_line_abv_curs_win(wp);
      invalidate_botline_win(wp);
      if (wp == curwin)
      {
  	update_topline();
  	curs_columns(TRUE);	/* validate w_wrow */
      }
      redraw_win_later(wp, NOT_VALID);
      wp->w_redr_status = TRUE;
  }
  #endif
  
      void
  win_comp_scroll(wp)
      win_T	*wp;
  {
      wp->w_p_scr = ((unsigned)wp->w_height >> 1);
      if (wp->w_p_scr == 0)
  	wp->w_p_scr = 1;
  }
  
  /*
   * command_height: called whenever p_ch has been changed
   */
      void
  command_height()
  {
  #ifdef FEAT_WINDOWS
      int		h;
      frame_T	*frp;
      int		old_p_ch = curtab->tp_ch_used;
  
      /* Use the value of p_ch that we remembered.  This is needed for when the
       * GUI starts up, we can't be sure in what order things happen.  And when
       * p_ch was changed in another tab page. */
      curtab->tp_ch_used = p_ch;
  
      /* Find bottom frame with width of screen. */
      frp = lastwin->w_frame;
  # ifdef FEAT_VERTSPLIT
      while (frp->fr_width != Columns && frp->fr_parent != NULL)
  	frp = frp->fr_parent;
  # endif
  
      /* Avoid changing the height of a window with 'winfixheight' set. */
      while (frp->fr_prev != NULL && frp->fr_layout == FR_LEAF
  						      && frp->fr_win->w_p_wfh)
  	frp = frp->fr_prev;
  
      if (starting != NO_SCREEN)
      {
  	cmdline_row = Rows - p_ch;
  
  	if (p_ch > old_p_ch)		    /* p_ch got bigger */
  	{
  	    while (p_ch > old_p_ch)
  	    {
  		if (frp == NULL)
  		{
  		    EMSG(_(e_noroom));
  		    p_ch = old_p_ch;
  		    curtab->tp_ch_used = p_ch;
  		    cmdline_row = Rows - p_ch;
  		    break;
  		}
  		h = frp->fr_height - frame_minheight(frp, NULL);
  		if (h > p_ch - old_p_ch)
  		    h = p_ch - old_p_ch;
  		old_p_ch += h;
  		frame_add_height(frp, -h);
  		frp = frp->fr_prev;
  	    }
  
  	    /* Recompute window positions. */
  	    (void)win_comp_pos();
  
  	    /* clear the lines added to cmdline */
  	    if (full_screen)
  		screen_fill((int)(cmdline_row), (int)Rows, 0,
  						   (int)Columns, ' ', ' ', 0);
  	    msg_row = cmdline_row;
  	    redraw_cmdline = TRUE;
  	    return;
  	}
  
  	if (msg_row < cmdline_row)
  	    msg_row = cmdline_row;
  	redraw_cmdline = TRUE;
      }
      frame_add_height(frp, (int)(old_p_ch - p_ch));
  
      /* Recompute window positions. */
      if (frp != lastwin->w_frame)
  	(void)win_comp_pos();
  #else
      cmdline_row = Rows - p_ch;
      win_setheight(cmdline_row);
  #endif
  }
  
  #if defined(FEAT_WINDOWS) || defined(PROTO)
  /*
   * Resize frame "frp" to be "n" lines higher (negative for less high).
   * Also resize the frames it is contained in.
   */
      static void
  frame_add_height(frp, n)
      frame_T	*frp;
      int		n;
  {
      frame_new_height(frp, frp->fr_height + n, FALSE, FALSE);
      for (;;)
      {
  	frp = frp->fr_parent;
  	if (frp == NULL)
  	    break;
  	frp->fr_height += n;
      }
  }
  
  /*
   * Add or remove a status line for the bottom window(s), according to the
   * value of 'laststatus'.
   */
      void
  last_status(morewin)
      int		morewin;	/* pretend there are two or more windows */
  {
      /* Don't make a difference between horizontal or vertical split. */
      last_status_rec(topframe, (p_ls == 2
  			  || (p_ls == 1 && (morewin || lastwin != firstwin))));
  }
  
      static void
  last_status_rec(fr, statusline)
      frame_T	*fr;
      int		statusline;
  {
      frame_T	*fp;
      win_T	*wp;
  
      if (fr->fr_layout == FR_LEAF)
      {
  	wp = fr->fr_win;
  	if (wp->w_status_height != 0 && !statusline)
  	{
  	    /* remove status line */
  	    win_new_height(wp, wp->w_height + 1);
  	    wp->w_status_height = 0;
  	    comp_col();
  	}
  	else if (wp->w_status_height == 0 && statusline)
  	{
  	    /* Find a frame to take a line from. */
  	    fp = fr;
  	    while (fp->fr_height <= frame_minheight(fp, NULL))
  	    {
  		if (fp == topframe)
  		{
  		    EMSG(_(e_noroom));
  		    return;
  		}
  		/* In a column of frames: go to frame above.  If already at
  		 * the top or in a row of frames: go to parent. */
  		if (fp->fr_parent->fr_layout == FR_COL && fp->fr_prev != NULL)
  		    fp = fp->fr_prev;
  		else
  		    fp = fp->fr_parent;
  	    }
  	    wp->w_status_height = 1;
  	    if (fp != fr)
  	    {
  		frame_new_height(fp, fp->fr_height - 1, FALSE, FALSE);
  		frame_fix_height(wp);
  		(void)win_comp_pos();
  	    }
  	    else
  		win_new_height(wp, wp->w_height - 1);
  	    comp_col();
  	    redraw_all_later(SOME_VALID);
  	}
      }
  #ifdef FEAT_VERTSPLIT
      else if (fr->fr_layout == FR_ROW)
      {
  	/* vertically split windows, set status line for each one */
  	for (fp = fr->fr_child; fp != NULL; fp = fp->fr_next)
  	    last_status_rec(fp, statusline);
      }
  #endif
      else
      {
  	/* horizontally split window, set status line for last one */
  	for (fp = fr->fr_child; fp->fr_next != NULL; fp = fp->fr_next)
  	    ;
  	last_status_rec(fp, statusline);
      }
  }
  
  /*
   * Return the number of lines used by the tab page line.
   */
      int
  tabline_height()
  {
  #ifdef FEAT_GUI_TABLINE
      /* When the GUI has the tabline then this always returns zero. */
      if (gui_use_tabline())
  	return 0;
  #endif
      switch (p_stal)
      {
  	case 0: return 0;
  	case 1: return (first_tabpage->tp_next == NULL) ? 0 : 1;
      }
      return 1;
  }
  
  #endif /* FEAT_WINDOWS */
  
  #if defined(FEAT_SEARCHPATH) || defined(PROTO)
  /*
   * Get the file name at the cursor.
   * If Visual mode is active, use the selected text if it's in one line.
   * Returns the name in allocated memory, NULL for failure.
   */
      char_u *
  grab_file_name(count, file_lnum)
      long	count;
      linenr_T	*file_lnum;
  {
  # ifdef FEAT_VISUAL
      if (VIsual_active)
      {
  	int	len;
  	char_u	*ptr;
  
  	if (get_visual_text(NULL, &ptr, &len) == FAIL)
  	    return NULL;
  	return find_file_name_in_path(ptr, len,
  		     FNAME_MESS|FNAME_EXP|FNAME_REL, count, curbuf->b_ffname);
      }
  # endif
      return file_name_at_cursor(FNAME_MESS|FNAME_HYP|FNAME_EXP|FNAME_REL, count,
  			       file_lnum);
  
  }
  
  /*
   * Return the file name under or after the cursor.
   *
   * The 'path' option is searched if the file name is not absolute.
   * The string returned has been alloc'ed and should be freed by the caller.
   * NULL is returned if the file name or file is not found.
   *
   * options:
   * FNAME_MESS	    give error messages
   * FNAME_EXP	    expand to path
   * FNAME_HYP	    check for hypertext link
   * FNAME_INCL	    apply "includeexpr"
   */
      char_u *
  file_name_at_cursor(options, count, file_lnum)
      int		options;
      long	count;
      linenr_T	*file_lnum;
  {
      return file_name_in_line(ml_get_curline(),
  		      curwin->w_cursor.col, options, count, curbuf->b_ffname,
  		      file_lnum);
  }
  
  /*
   * Return the name of the file under or after ptr[col].
   * Otherwise like file_name_at_cursor().
   */
      char_u *
  file_name_in_line(line, col, options, count, rel_fname, file_lnum)
      char_u	*line;
      int		col;
      int		options;
      long	count;
      char_u	*rel_fname;	/* file we are searching relative to */
      linenr_T	*file_lnum;	/* line number after the file name */
  {
      char_u	*ptr;
      int		len;
  
      /*
       * search forward for what could be the start of a file name
       */
      ptr = line + col;
      while (*ptr != NUL && !vim_isfilec(*ptr))
  	mb_ptr_adv(ptr);
      if (*ptr == NUL)		/* nothing found */
      {
  	if (options & FNAME_MESS)
  	    EMSG(_("E446: No file name under cursor"));
  	return NULL;
      }
  
      /*
       * Search backward for first char of the file name.
       * Go one char back to ":" before "//" even when ':' is not in 'isfname'.
       */
      while (ptr > line)
      {
  #ifdef FEAT_MBYTE
  	if (has_mbyte && (len = (*mb_head_off)(line, ptr - 1)) > 0)
  	    ptr -= len + 1;
  	else
  #endif
  	if (vim_isfilec(ptr[-1])
  		|| ((options & FNAME_HYP) && path_is_url(ptr - 1)))
  	    --ptr;
  	else
  	    break;
      }
  
      /*
       * Search forward for the last char of the file name.
       * Also allow "://" when ':' is not in 'isfname'.
       */
      len = 0;
      while (vim_isfilec(ptr[len])
  			 || ((options & FNAME_HYP) && path_is_url(ptr + len)))
  #ifdef FEAT_MBYTE
  	if (has_mbyte)
  	    len += (*mb_ptr2len)(ptr + len);
  	else
  #endif
  	    ++len;
  
      /*
       * If there is trailing punctuation, remove it.
       * But don't remove "..", could be a directory name.
       */
      if (len > 2 && vim_strchr((char_u *)".,:;!", ptr[len - 1]) != NULL
  						       && ptr[len - 2] != '.')
  	--len;
  
      if (file_lnum != NULL)
      {
  	char_u *p;
  
  	/* Get the number after the file name and a separator character */
  	p = ptr + len;
  	p = skipwhite(p);
  	if (*p != NUL)
  	{
  	    if (!isdigit(*p))
  		++p;		    /* skip the separator */
  	    p = skipwhite(p);
  	    if (isdigit(*p))
  		*file_lnum = (int)getdigits(&p);
  	}
      }
  
      return find_file_name_in_path(ptr, len, options, count, rel_fname);
  }
  
  # if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
  static char_u *eval_includeexpr __ARGS((char_u *ptr, int len));
  
      static char_u *
  eval_includeexpr(ptr, len)
      char_u	*ptr;
      int		len;
  {
      char_u	*res;
  
      set_vim_var_string(VV_FNAME, ptr, len);
      res = eval_to_string_safe(curbuf->b_p_inex, NULL,
  		      was_set_insecurely((char_u *)"includeexpr", OPT_LOCAL));
      set_vim_var_string(VV_FNAME, NULL, 0);
      return res;
  }
  #endif
  
  /*
   * Return the name of the file ptr[len] in 'path'.
   * Otherwise like file_name_at_cursor().
   */
      char_u *
  find_file_name_in_path(ptr, len, options, count, rel_fname)
      char_u	*ptr;
      int		len;
      int		options;
      long	count;
      char_u	*rel_fname;	/* file we are searching relative to */
  {
      char_u	*file_name;
      int		c;
  # if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
      char_u	*tofree = NULL;
  
      if ((options & FNAME_INCL) && *curbuf->b_p_inex != NUL)
      {
  	tofree = eval_includeexpr(ptr, len);
  	if (tofree != NULL)
  	{
  	    ptr = tofree;
  	    len = (int)STRLEN(ptr);
  	}
      }
  # endif
  
      if (options & FNAME_EXP)
      {
  	file_name = find_file_in_path(ptr, len, options & ~FNAME_MESS,
  							     TRUE, rel_fname);
  
  # if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
  	/*
  	 * If the file could not be found in a normal way, try applying
  	 * 'includeexpr' (unless done already).
  	 */
  	if (file_name == NULL
  		&& !(options & FNAME_INCL) && *curbuf->b_p_inex != NUL)
  	{
  	    tofree = eval_includeexpr(ptr, len);
  	    if (tofree != NULL)
  	    {
  		ptr = tofree;
  		len = (int)STRLEN(ptr);
  		file_name = find_file_in_path(ptr, len, options & ~FNAME_MESS,
  							     TRUE, rel_fname);
  	    }
  	}
  # endif
  	if (file_name == NULL && (options & FNAME_MESS))
  	{
  	    c = ptr[len];
  	    ptr[len] = NUL;
  	    EMSG2(_("E447: Can't find file \"%s\" in path"), ptr);
  	    ptr[len] = c;
  	}
  
  	/* Repeat finding the file "count" times.  This matters when it
  	 * appears several times in the path. */
  	while (file_name != NULL && --count > 0)
  	{
  	    vim_free(file_name);
  	    file_name = find_file_in_path(ptr, len, options, FALSE, rel_fname);
  	}
      }
      else
  	file_name = vim_strnsave(ptr, len);
  
  # if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
      vim_free(tofree);
  # endif
  
      return file_name;
  }
  #endif /* FEAT_SEARCHPATH */
  
  /*
   * Check if the "://" of a URL is at the pointer, return URL_SLASH.
   * Also check for ":\\", which MS Internet Explorer accepts, return
   * URL_BACKSLASH.
   */
      static int
  path_is_url(p)
      char_u  *p;
  {
      if (STRNCMP(p, "://", (size_t)3) == 0)
  	return URL_SLASH;
      else if (STRNCMP(p, ":\\\\", (size_t)3) == 0)
  	return URL_BACKSLASH;
      return 0;
  }
  
  /*
   * Check if "fname" starts with "name://".  Return URL_SLASH if it does.
   * Return URL_BACKSLASH for "name:\\".
   * Return zero otherwise.
   */
      int
  path_with_url(fname)
      char_u *fname;
  {
      char_u *p;
  
      for (p = fname; isalpha(*p); ++p)
  	;
      return path_is_url(p);
  }
  
  /*
   * Return TRUE if "name" is a full (absolute) path name or URL.
   */
      int
  vim_isAbsName(name)
      char_u	*name;
  {
      return (path_with_url(name) != 0 || mch_isFullName(name));
  }
  
  /*
   * Get absolute file name into buffer "buf[len]".
   *
   * return FAIL for failure, OK otherwise
   */
      int
  vim_FullName(fname, buf, len, force)
      char_u	*fname, *buf;
      int		len;
      int		force;	    /* force expansion even when already absolute */
  {
      int		retval = OK;
      int		url;
  
      *buf = NUL;
      if (fname == NULL)
  	return FAIL;
  
      url = path_with_url(fname);
      if (!url)
  	retval = mch_FullName(fname, buf, len, force);
      if (url || retval == FAIL)
      {
  	/* something failed; use the file name (truncate when too long) */
  	vim_strncpy(buf, fname, len - 1);
      }
  #if defined(MACOS_CLASSIC) || defined(OS2) || defined(MSDOS) || defined(MSWIN)
      slash_adjust(buf);
  #endif
      return retval;
  }
  
  /*
   * Return the minimal number of rows that is needed on the screen to display
   * the current number of windows.
   */
      int
  min_rows()
  {
      int		total;
  #ifdef FEAT_WINDOWS
      tabpage_T	*tp;
      int		n;
  #endif
  
      if (firstwin == NULL)	/* not initialized yet */
  	return MIN_LINES;
  
  #ifdef FEAT_WINDOWS
      total = 0;
      for (tp = first_tabpage; tp != NULL; tp = tp->tp_next)
      {
  	n = frame_minheight(tp->tp_topframe, NULL);
  	if (total < n)
  	    total = n;
      }
      total += tabline_height();
  #else
      total = 1;		/* at least one window should have a line! */
  #endif
      total += 1;		/* count the room for the command line */
      return total;
  }
  
  /*
   * Return TRUE if there is only one window (in the current tab page), not
   * counting a help or preview window, unless it is the current window.
   * Does not count "aucmd_win".
   */
      int
  only_one_window()
  {
  #ifdef FEAT_WINDOWS
      int		count = 0;
      win_T	*wp;
  
      /* If there is another tab page there always is another window. */
      if (first_tabpage->tp_next != NULL)
  	return FALSE;
  
      for (wp = firstwin; wp != NULL; wp = wp->w_next)
  	if (wp->w_buffer != NULL
  		&& (!((wp->w_buffer->b_help && !curbuf->b_help)
  # ifdef FEAT_QUICKFIX
  		    || wp->w_p_pvw
  # endif
  	     ) || wp == curwin)
  # ifdef FEAT_AUTOCMD
  		&& wp != aucmd_win
  # endif
  	   )
  	    ++count;
      return (count <= 1);
  #else
      return TRUE;
  #endif
  }
  
  #if defined(FEAT_WINDOWS) || defined(FEAT_AUTOCMD) || defined(PROTO)
  /*
   * Correct the cursor line number in other windows.  Used after changing the
   * current buffer, and before applying autocommands.
   * When "do_curwin" is TRUE, also check current window.
   */
      void
  check_lnums(do_curwin)
      int		do_curwin;
  {
      win_T	*wp;
  
  #ifdef FEAT_WINDOWS
      tabpage_T	*tp;
  
      FOR_ALL_TAB_WINDOWS(tp, wp)
  	if ((do_curwin || wp != curwin) && wp->w_buffer == curbuf)
  #else
      wp = curwin;
      if (do_curwin)
  #endif
  	{
  	    if (wp->w_cursor.lnum > curbuf->b_ml.ml_line_count)
  		wp->w_cursor.lnum = curbuf->b_ml.ml_line_count;
  	    if (wp->w_topline > curbuf->b_ml.ml_line_count)
  		wp->w_topline = curbuf->b_ml.ml_line_count;
  	}
  }
  #endif
  
  #if defined(FEAT_WINDOWS) || defined(PROTO)
  
  /*
   * A snapshot of the window sizes, to restore them after closing the help
   * window.
   * Only these fields are used:
   * fr_layout
   * fr_width
   * fr_height
   * fr_next
   * fr_child
   * fr_win (only valid for the old curwin, NULL otherwise)
   */
  
  /*
   * Create a snapshot of the current frame sizes.
   */
      void
  make_snapshot(idx)
      int idx;
  {
      clear_snapshot(curtab, idx);
      make_snapshot_rec(topframe, &curtab->tp_snapshot[idx]);
  }
  
      static void
  make_snapshot_rec(fr, frp)
      frame_T	*fr;
      frame_T	**frp;
  {
      *frp = (frame_T *)alloc_clear((unsigned)sizeof(frame_T));
      if (*frp == NULL)
  	return;
      (*frp)->fr_layout = fr->fr_layout;
  # ifdef FEAT_VERTSPLIT
      (*frp)->fr_width = fr->fr_width;
  # endif
      (*frp)->fr_height = fr->fr_height;
      if (fr->fr_next != NULL)
  	make_snapshot_rec(fr->fr_next, &((*frp)->fr_next));
      if (fr->fr_child != NULL)
  	make_snapshot_rec(fr->fr_child, &((*frp)->fr_child));
      if (fr->fr_layout == FR_LEAF && fr->fr_win == curwin)
  	(*frp)->fr_win = curwin;
  }
  
  /*
   * Remove any existing snapshot.
   */
      static void
  clear_snapshot(tp, idx)
      tabpage_T	*tp;
      int		idx;
  {
      clear_snapshot_rec(tp->tp_snapshot[idx]);
      tp->tp_snapshot[idx] = NULL;
  }
  
      static void
  clear_snapshot_rec(fr)
      frame_T	*fr;
  {
      if (fr != NULL)
      {
  	clear_snapshot_rec(fr->fr_next);
  	clear_snapshot_rec(fr->fr_child);
  	vim_free(fr);
      }
  }
  
  /*
   * Restore a previously created snapshot, if there is any.
   * This is only done if the screen size didn't change and the window layout is
   * still the same.
   */
      void
  restore_snapshot(idx, close_curwin)
      int		idx;
      int		close_curwin;	    /* closing current window */
  {
      win_T	*wp;
  
      if (curtab->tp_snapshot[idx] != NULL
  # ifdef FEAT_VERTSPLIT
  	    && curtab->tp_snapshot[idx]->fr_width == topframe->fr_width
  # endif
  	    && curtab->tp_snapshot[idx]->fr_height == topframe->fr_height
  	    && check_snapshot_rec(curtab->tp_snapshot[idx], topframe) == OK)
      {
  	wp = restore_snapshot_rec(curtab->tp_snapshot[idx], topframe);
  	win_comp_pos();
  	if (wp != NULL && close_curwin)
  	    win_goto(wp);
  	redraw_all_later(CLEAR);
      }
      clear_snapshot(curtab, idx);
  }
  
  /*
   * Check if frames "sn" and "fr" have the same layout, same following frames
   * and same children.
   */
      static int
  check_snapshot_rec(sn, fr)
      frame_T	*sn;
      frame_T	*fr;
  {
      if (sn->fr_layout != fr->fr_layout
  	    || (sn->fr_next == NULL) != (fr->fr_next == NULL)
  	    || (sn->fr_child == NULL) != (fr->fr_child == NULL)
  	    || (sn->fr_next != NULL
  		&& check_snapshot_rec(sn->fr_next, fr->fr_next) == FAIL)
  	    || (sn->fr_child != NULL
  		&& check_snapshot_rec(sn->fr_child, fr->fr_child) == FAIL))
  	return FAIL;
      return OK;
  }
  
  /*
   * Copy the size of snapshot frame "sn" to frame "fr".  Do the same for all
   * following frames and children.
   * Returns a pointer to the old current window, or NULL.
   */
      static win_T *
  restore_snapshot_rec(sn, fr)
      frame_T	*sn;
      frame_T	*fr;
  {
      win_T	*wp = NULL;
      win_T	*wp2;
  
      fr->fr_height = sn->fr_height;
  # ifdef FEAT_VERTSPLIT
      fr->fr_width = sn->fr_width;
  # endif
      if (fr->fr_layout == FR_LEAF)
      {
  	frame_new_height(fr, fr->fr_height, FALSE, FALSE);
  # ifdef FEAT_VERTSPLIT
  	frame_new_width(fr, fr->fr_width, FALSE, FALSE);
  # endif
  	wp = sn->fr_win;
      }
      if (sn->fr_next != NULL)
      {
  	wp2 = restore_snapshot_rec(sn->fr_next, fr->fr_next);
  	if (wp2 != NULL)
  	    wp = wp2;
      }
      if (sn->fr_child != NULL)
      {
  	wp2 = restore_snapshot_rec(sn->fr_child, fr->fr_child);
  	if (wp2 != NULL)
  	    wp = wp2;
      }
      return wp;
  }
  
  #endif
  
  #if defined(FEAT_EVAL) || defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) \
  	|| defined(PROTO)
  /*
   * Set "win" to be the curwin and "tp" to be the current tab page.
   * restore_win() MUST be called to undo.
   * No autocommands will be executed.
   * When "no_display" is TRUE the display won't be affected, no redraw is
   * triggered, another tabpage access is limited.
   * Returns FAIL if switching to "win" failed.
   */
      int
  switch_win(save_curwin, save_curtab, win, tp, no_display)
      win_T	**save_curwin UNUSED;
      tabpage_T	**save_curtab UNUSED;
      win_T	*win UNUSED;
      tabpage_T	*tp UNUSED;
      int		no_display UNUSED;
  {
  # ifdef FEAT_AUTOCMD
      block_autocmds();
  # endif
  # ifdef FEAT_WINDOWS
      *save_curwin = curwin;
      if (tp != NULL)
      {
  	*save_curtab = curtab;
  	if (no_display)
  	{
  	    curtab->tp_firstwin = firstwin;
  	    curtab->tp_lastwin = lastwin;
  	    curtab = tp;
  	    firstwin = curtab->tp_firstwin;
  	    lastwin = curtab->tp_lastwin;
  	}
  	else
  	    goto_tabpage_tp(tp, FALSE, FALSE);
      }
      if (!win_valid(win))
      {
  # ifdef FEAT_AUTOCMD
  	unblock_autocmds();
  # endif
  	return FAIL;
      }
      curwin = win;
      curbuf = curwin->w_buffer;
  # endif
      return OK;
  }
  
  /*
   * Restore current tabpage and window saved by switch_win(), if still valid.
   * When "no_display" is TRUE the display won't be affected, no redraw is
   * triggered.
   */
      void
  restore_win(save_curwin, save_curtab, no_display)
      win_T	*save_curwin UNUSED;
      tabpage_T	*save_curtab UNUSED;
      int		no_display UNUSED;
  {
  # ifdef FEAT_WINDOWS
      if (save_curtab != NULL && valid_tabpage(save_curtab))
      {
  	if (no_display)
  	{
  	    curtab->tp_firstwin = firstwin;
  	    curtab->tp_lastwin = lastwin;
  	    curtab = save_curtab;
  	    firstwin = curtab->tp_firstwin;
  	    lastwin = curtab->tp_lastwin;
  	}
  	else
  	    goto_tabpage_tp(save_curtab, FALSE, FALSE);
      }
      if (win_valid(save_curwin))
      {
  	curwin = save_curwin;
  	curbuf = curwin->w_buffer;
      }
  # endif
  # ifdef FEAT_AUTOCMD
      unblock_autocmds();
  # endif
  }
  
  /*
   * Make "buf" the current buffer.  restore_buffer() MUST be called to undo.
   * No autocommands will be executed.  Use aucmd_prepbuf() if there are any.
   */
      void
  switch_buffer(save_curbuf, buf)
      buf_T *buf;
      buf_T **save_curbuf;
  {
  # ifdef FEAT_AUTOCMD
      block_autocmds();
  # endif
      *save_curbuf = curbuf;
      --curbuf->b_nwindows;
      curbuf = buf;
      curwin->w_buffer = buf;
      ++curbuf->b_nwindows;
  }
  
  /*
   * Restore the current buffer after using switch_buffer().
   */
      void
  restore_buffer(save_curbuf)
      buf_T *save_curbuf;
  {
  # ifdef FEAT_AUTOCMD
      unblock_autocmds();
  # endif
      /* Check for valid buffer, just in case. */
      if (buf_valid(save_curbuf))
      {
  	--curbuf->b_nwindows;
  	curwin->w_buffer = save_curbuf;
  	curbuf = save_curbuf;
  	++curbuf->b_nwindows;
      }
  }
  #endif
  
  #if (defined(FEAT_GUI) && defined(FEAT_VERTSPLIT)) || defined(PROTO)
  /*
   * Return TRUE if there is any vertically split window.
   */
      int
  win_hasvertsplit()
  {
      frame_T	*fr;
  
      if (topframe->fr_layout == FR_ROW)
  	return TRUE;
  
      if (topframe->fr_layout == FR_COL)
  	for (fr = topframe->fr_child; fr != NULL; fr = fr->fr_next)
  	    if (fr->fr_layout == FR_ROW)
  		return TRUE;
  
      return FALSE;
  }
  #endif
  
  #if defined(FEAT_SEARCH_EXTRA) || defined(PROTO)
  /*
   * Add match to the match list of window 'wp'.  The pattern 'pat' will be
   * highlighted with the group 'grp' with priority 'prio'.
   * Optionally, a desired ID 'id' can be specified (greater than or equal to 1).
   * If no particular ID is desired, -1 must be specified for 'id'.
   * Return ID of added match, -1 on failure.
   */
      int
  match_add(wp, grp, pat, prio, id)
      win_T	*wp;
      char_u	*grp;
      char_u	*pat;
      int		prio;
      int		id;
  {
      matchitem_T *cur;
      matchitem_T *prev;
      matchitem_T *m;
      int		hlg_id;
      regprog_T	*regprog;
  
      if (*grp == NUL || *pat == NUL)
  	return -1;
      if (id < -1 || id == 0)
      {
  	EMSGN("E799: Invalid ID: %ld (must be greater than or equal to 1)", id);
  	return -1;
      }
      if (id != -1)
      {
  	cur = wp->w_match_head;
  	while (cur != NULL)
  	{
  	    if (cur->id == id)
  	    {
  		EMSGN("E801: ID already taken: %ld", id);
  		return -1;
  	    }
  	    cur = cur->next;
  	}
      }
      if ((hlg_id = syn_namen2id(grp, (int)STRLEN(grp))) == 0)
      {
  	EMSG2(_(e_nogroup), grp);
  	return -1;
      }
      if ((regprog = vim_regcomp(pat, RE_MAGIC)) == NULL)
      {
  	EMSG2(_(e_invarg2), pat);
  	return -1;
      }
  
      /* Find available match ID. */
      while (id == -1)
      {
  	cur = wp->w_match_head;
  	while (cur != NULL && cur->id != wp->w_next_match_id)
  	    cur = cur->next;
  	if (cur == NULL)
  	    id = wp->w_next_match_id;
  	wp->w_next_match_id++;
      }
  
      /* Build new match. */
      m = (matchitem_T *)alloc(sizeof(matchitem_T));
      m->id = id;
      m->priority = prio;
      m->pattern = vim_strsave(pat);
      m->hlg_id = hlg_id;
      m->match.regprog = regprog;
      m->match.rmm_ic = FALSE;
      m->match.rmm_maxcol = 0;
  
      /* Insert new match.  The match list is in ascending order with regard to
       * the match priorities. */
      cur = wp->w_match_head;
      prev = cur;
      while (cur != NULL && prio >= cur->priority)
      {
  	prev = cur;
  	cur = cur->next;
      }
      if (cur == prev)
  	wp->w_match_head = m;
      else
  	prev->next = m;
      m->next = cur;
  
      redraw_later(SOME_VALID);
      return id;
  }
  
  /*
   * Delete match with ID 'id' in the match list of window 'wp'.
   * Print error messages if 'perr' is TRUE.
   */
      int
  match_delete(wp, id, perr)
      win_T	*wp;
      int		id;
      int		perr;
  {
      matchitem_T *cur = wp->w_match_head;
      matchitem_T *prev = cur;
  
      if (id < 1)
      {
  	if (perr == TRUE)
  	    EMSGN("E802: Invalid ID: %ld (must be greater than or equal to 1)",
  									  id);
  	return -1;
      }
      while (cur != NULL && cur->id != id)
      {
  	prev = cur;
  	cur = cur->next;
      }
      if (cur == NULL)
      {
  	if (perr == TRUE)
  	    EMSGN("E803: ID not found: %ld", id);
  	return -1;
      }
      if (cur == prev)
  	wp->w_match_head = cur->next;
      else
  	prev->next = cur->next;
      vim_regfree(cur->match.regprog);
      vim_free(cur->pattern);
      vim_free(cur);
      redraw_later(SOME_VALID);
      return 0;
  }
  
  /*
   * Delete all matches in the match list of window 'wp'.
   */
      void
  clear_matches(wp)
      win_T	*wp;
  {
      matchitem_T *m;
  
      while (wp->w_match_head != NULL)
      {
  	m = wp->w_match_head->next;
  	vim_regfree(wp->w_match_head->match.regprog);
  	vim_free(wp->w_match_head->pattern);
  	vim_free(wp->w_match_head);
  	wp->w_match_head = m;
      }
      redraw_later(SOME_VALID);
  }
  
  /*
   * Get match from ID 'id' in window 'wp'.
   * Return NULL if match not found.
   */
      matchitem_T *
  get_match(wp, id)
      win_T	*wp;
      int		id;
  {
      matchitem_T *cur = wp->w_match_head;
  
      while (cur != NULL && cur->id != id)
  	cur = cur->next;
      return cur;
  }
  #endif
  
  #if defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) || defined(PROTO)
      int
  get_win_number(win_T *wp, win_T *first_win)
  {
      int		i = 1;
      win_T	*w;
  
      for (w = first_win; w != NULL && w != wp; w = W_NEXT(w))
  	++i;
  
      if (w == NULL)
  	return 0;
      else
  	return i;
  }
  
      int
  get_tab_number(tabpage_T *tp UNUSED)
  {
      int		i = 1;
  # ifdef FEAT_WINDOWS
      tabpage_T	*t;
  
      for (t = first_tabpage; t != NULL && t != tp; t = t->tp_next)
  	++i;
  
      if (t == NULL)
  	return 0;
      else
  # endif
  	return i;
  }
  #endif
  
  #ifdef FEAT_WINDOWS
  /*
   * Return TRUE if "topfrp" and its children are at the right height.
   */
      static int
  frame_check_height(topfrp, height)
      frame_T *topfrp;
      int	    height;
  {
      frame_T *frp;
  
      if (topfrp->fr_height != height)
  	return FALSE;
  
      if (topfrp->fr_layout == FR_ROW)
  	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
  	    if (frp->fr_height != height)
  		return FALSE;
  
      return TRUE;
  }
  #endif
  
  #ifdef FEAT_VERTSPLIT
  /*
   * Return TRUE if "topfrp" and its children are at the right width.
   */
      static int
  frame_check_width(topfrp, width)
      frame_T *topfrp;
      int	    width;
  {
      frame_T *frp;
  
      if (topfrp->fr_width != width)
  	return FALSE;
  
      if (topfrp->fr_layout == FR_COL)
  	for (frp = topfrp->fr_child; frp != NULL; frp = frp->fr_next)
  	    if (frp->fr_width != width)
  		return FALSE;
  
      return TRUE;
  }
  #endif
  
  