text: /* vi:set ts=8 sts=4 sw=4 noet:
   *
   * VIM - Vi IMproved	by Bram Moolenaar
   *
   * Do ":help uganda"  in Vim to read copying and usage conditions.
   * Do ":help credits" in Vim to see a list of people who contributed.
   * See README.txt for an overview of the Vim source code.
   */
  
  /*
   * syntax.c: code for syntax highlighting
   */
  
  #include "vim.h"
  
  #if defined(FEAT_SYN_HL) || defined(PROTO)
  
  #define SYN_NAMELEN	50		// maximum length of a syntax name
  
  // different types of offsets that are possible
  #define SPO_MS_OFF	0	// match  start offset
  #define SPO_ME_OFF	1	// match  end	offset
  #define SPO_HS_OFF	2	// highl. start offset
  #define SPO_HE_OFF	3	// highl. end	offset
  #define SPO_RS_OFF	4	// region start offset
  #define SPO_RE_OFF	5	// region end	offset
  #define SPO_LC_OFF	6	// leading context offset
  #define SPO_COUNT	7
  
  static char *(spo_name_tab[SPO_COUNT]) =
  	    {"ms=", "me=", "hs=", "he=", "rs=", "re=", "lc="};
  
  /*
   * The patterns that are being searched for are stored in a syn_pattern.
   * A match item consists of one pattern.
   * A start/end item consists of n start patterns and m end patterns.
   * A start/skip/end item consists of n start patterns, one skip pattern and m
   * end patterns.
   * For the latter two, the patterns are always consecutive: start-skip-end.
   *
   * A character offset can be given for the matched text (_m_start and _m_end)
   * and for the actually highlighted text (_h_start and _h_end).
   *
   * Note that ordering of members is optimized to reduce padding.
   */
  typedef struct syn_pattern
  {
      char	 sp_type;		// see SPTYPE_ defines below
      char	 sp_syncing;		// this item used for syncing
      short	 sp_syn_match_id;	// highlight group ID of pattern
      short	 sp_off_flags;		// see below
      int		 sp_offsets[SPO_COUNT];	// offsets
      int		 sp_flags;		// see HL_ defines below
  #ifdef FEAT_CONCEAL
      int		 sp_cchar;		// conceal substitute character
  #endif
      int		 sp_ic;			// ignore-case flag for sp_prog
      int		 sp_sync_idx;		// sync item index (syncing only)
      int		 sp_line_id;		// ID of last line where tried
      int		 sp_startcol;		// next match in sp_line_id line
      short	*sp_cont_list;		// cont. group IDs, if non-zero
      short	*sp_next_list;		// next group IDs, if non-zero
      struct sp_syn sp_syn;		// struct passed to in_id_list()
      char_u	*sp_pattern;		// regexp to match, pattern
      regprog_T	*sp_prog;		// regexp to match, program
  #ifdef FEAT_PROFILE
      syn_time_T	 sp_time;
  #endif
  } synpat_T;
  
  // The sp_off_flags are computed like this:
  // offset from the start of the matched text: (1 << SPO_XX_OFF)
  // offset from the end	 of the matched text: (1 << (SPO_XX_OFF + SPO_COUNT))
  // When both are present, only one is used.
  
  #define SPTYPE_MATCH	1	// match keyword with this group ID
  #define SPTYPE_START	2	// match a regexp, start of item
  #define SPTYPE_END	3	// match a regexp, end of item
  #define SPTYPE_SKIP	4	// match a regexp, skip within item
  
  
  #define SYN_ITEMS(buf)	((synpat_T *)((buf)->b_syn_patterns.ga_data))
  
  #define NONE_IDX	-2	// value of sp_sync_idx for "NONE"
  
  /*
   * Flags for b_syn_sync_flags:
   */
  #define SF_CCOMMENT	0x01	// sync on a C-style comment
  #define SF_MATCH	0x02	// sync by matching a pattern
  
  #define SYN_STATE_P(ssp)    ((bufstate_T *)((ssp)->ga_data))
  
  #define MAXKEYWLEN	80	    // maximum length of a keyword
  
  /*
   * The attributes of the syntax item that has been recognized.
   */
  static int current_attr = 0;	    // attr of current syntax word
  #ifdef FEAT_EVAL
  static int current_id = 0;	    // ID of current char for syn_get_id()
  static int current_trans_id = 0;    // idem, transparency removed
  #endif
  #ifdef FEAT_CONCEAL
  static int current_flags = 0;
  static int current_seqnr = 0;
  static int current_sub_char = 0;
  #endif
  
  typedef struct syn_cluster_S
  {
      char_u	    *scl_name;	    // syntax cluster name
      char_u	    *scl_name_u;    // uppercase of scl_name
      short	    *scl_list;	    // IDs in this syntax cluster
  } syn_cluster_T;
  
  /*
   * Methods of combining two clusters
   */
  #define CLUSTER_REPLACE	    1	// replace first list with second
  #define CLUSTER_ADD	    2	// add second list to first
  #define CLUSTER_SUBTRACT    3	// subtract second list from first
  
  #define SYN_CLSTR(buf)	((syn_cluster_T *)((buf)->b_syn_clusters.ga_data))
  
  /*
   * Syntax group IDs have different types:
   *     0 - 19999  normal syntax groups
   * 20000 - 20999  ALLBUT indicator (current_syn_inc_tag added)
   * 21000 - 21999  TOP indicator (current_syn_inc_tag added)
   * 22000 - 22999  CONTAINED indicator (current_syn_inc_tag added)
   * 23000 - 32767  cluster IDs (subtract SYNID_CLUSTER for the cluster ID)
   */
  #define SYNID_ALLBUT	MAX_HL_ID   // syntax group ID for contains=ALLBUT
  #define SYNID_TOP	21000	    // syntax group ID for contains=TOP
  #define SYNID_CONTAINED	22000	    // syntax group ID for contains=CONTAINED
  #define SYNID_CLUSTER	23000	    // first syntax group ID for clusters
  
  #define MAX_SYN_INC_TAG	999	    // maximum before the above overflow
  #define MAX_CLUSTER_ID  (32767 - SYNID_CLUSTER)
  
  /*
   * Annoying Hack(TM):  ":syn include" needs this pointer to pass to
   * expand_filename().  Most of the other syntax commands don't need it, so
   * instead of passing it to them, we stow it here.
   */
  static char_u **syn_cmdlinep;
  
  /*
   * Another Annoying Hack(TM):  To prevent rules from other ":syn include"'d
   * files from leaking into ALLBUT lists, we assign a unique ID to the
   * rules in each ":syn include"'d file.
   */
  static int current_syn_inc_tag = 0;
  static int running_syn_inc_tag = 0;
  
  /*
   * In a hashtable item "hi_key" points to "keyword" in a keyentry.
   * This avoids adding a pointer to the hashtable item.
   * KE2HIKEY() converts a var pointer to a hashitem key pointer.
   * HIKEY2KE() converts a hashitem key pointer to a var pointer.
   * HI2KE() converts a hashitem pointer to a var pointer.
   */
  static keyentry_T dumkey;
  #define KE2HIKEY(kp)  ((kp)->keyword)
  #define HIKEY2KE(p)   ((keyentry_T *)((p) - (dumkey.keyword - (char_u *)&dumkey)))
  #define HI2KE(hi)      HIKEY2KE((hi)->hi_key)
  
  /*
   * To reduce the time spent in keepend(), remember at which level in the state
   * stack the first item with "keepend" is present.  When "-1", there is no
   * "keepend" on the stack.
   */
  static int keepend_level = -1;
  
  static char msg_no_items[] = N_("No Syntax items defined for this buffer");
  
  /*
   * For the current state we need to remember more than just the idx.
   * When si_m_endpos.lnum is 0, the items other than si_idx are unknown.
   * (The end positions have the column number of the next char)
   */
  typedef struct state_item
  {
      int		si_idx;			// index of syntax pattern or
  					// KEYWORD_IDX
      int		si_id;			// highlight group ID for keywords
      int		si_trans_id;		// idem, transparency removed
      int		si_m_lnum;		// lnum of the match
      int		si_m_startcol;		// starting column of the match
      lpos_T	si_m_endpos;		// just after end posn of the match
      lpos_T	si_h_startpos;		// start position of the highlighting
      lpos_T	si_h_endpos;		// end position of the highlighting
      lpos_T	si_eoe_pos;		// end position of end pattern
      int		si_end_idx;		// group ID for end pattern or zero
      int		si_ends;		// if match ends before si_m_endpos
      int		si_attr;		// attributes in this state
      long	si_flags;		// HL_HAS_EOL flag in this state, and
  					// HL_SKIP* for si_next_list
  #ifdef FEAT_CONCEAL
      int		si_seqnr;		// sequence number
      int		si_cchar;		// substitution character for conceal
  #endif
      short	*si_cont_list;		// list of contained groups
      short	*si_next_list;		// nextgroup IDs after this item ends
      reg_extmatch_T *si_extmatch;	// \z(...\) matches from start
  					// pattern
  } stateitem_T;
  
  #define KEYWORD_IDX	-1	    // value of si_idx for keywords
  #define ID_LIST_ALL	(short *)-1 // valid of si_cont_list for containing all
  				    // but contained groups
  
  #ifdef FEAT_CONCEAL
  static int next_seqnr = 1;		// value to use for si_seqnr
  #endif
  
  /*
   * Struct to reduce the number of arguments to get_syn_options(), it's used
   * very often.
   */
  typedef struct
  {
      int		flags;		// flags for contained and transparent
      int		keyword;	// TRUE for ":syn keyword"
      int		*sync_idx;	// syntax item for "grouphere" argument, NULL
  				// if not allowed
      char	has_cont_list;	// TRUE if "cont_list" can be used
      short	*cont_list;	// group IDs for "contains" argument
      short	*cont_in_list;	// group IDs for "containedin" argument
      short	*next_list;	// group IDs for "nextgroup" argument
  } syn_opt_arg_T;
  
  /*
   * The next possible match in the current line for any pattern is remembered,
   * to avoid having to try for a match in each column.
   * If next_match_idx == -1, not tried (in this line) yet.
   * If next_match_col == MAXCOL, no match found in this line.
   * (All end positions have the column of the char after the end)
   */
  static int next_match_col;		// column for start of next match
  static lpos_T next_match_m_endpos;	// position for end of next match
  static lpos_T next_match_h_startpos;	// pos. for highl. start of next match
  static lpos_T next_match_h_endpos;	// pos. for highl. end of next match
  static int next_match_idx;		// index of matched item
  static long next_match_flags;		// flags for next match
  static lpos_T next_match_eos_pos;	// end of start pattn (start region)
  static lpos_T next_match_eoe_pos;	// pos. for end of end pattern
  static int next_match_end_idx;		// ID of group for end pattn or zero
  static reg_extmatch_T *next_match_extmatch = NULL;
  
  /*
   * A state stack is an array of integers or stateitem_T, stored in a
   * garray_T.  A state stack is invalid if its itemsize entry is zero.
   */
  #define INVALID_STATE(ssp)  ((ssp)->ga_itemsize == 0)
  #define VALID_STATE(ssp)    ((ssp)->ga_itemsize != 0)
  
  #define FOR_ALL_SYNSTATES(sb, sst) \
      for ((sst) = (sb)->b_sst_first; (sst) != NULL; (sst) = (sst)->sst_next)
  
  /*
   * The current state (within the line) of the recognition engine.
   * When current_state.ga_itemsize is 0 the current state is invalid.
   */
  static win_T	*syn_win;		// current window for highlighting
  static buf_T	*syn_buf;		// current buffer for highlighting
  static synblock_T *syn_block;		// current buffer for highlighting
  #ifdef FEAT_RELTIME
  static proftime_T *syn_tm;		// timeout limit
  #endif
  static linenr_T current_lnum = 0;	// lnum of current state
  static colnr_T	current_col = 0;	// column of current state
  static int	current_state_stored = 0; // TRUE if stored current state
  					  // after setting current_finished
  static int	current_finished = 0;	// current line has been finished
  static garray_T current_state		// current stack of state_items
  		= {0, 0, 0, 0, NULL};
  static short	*current_next_list = NULL; // when non-zero, nextgroup list
  static int	current_next_flags = 0; // flags for current_next_list
  static int	current_line_id = 0;	// unique number for current line
  
  #define CUR_STATE(idx)	((stateitem_T *)(current_state.ga_data))[idx]
  
  static void syn_sync(win_T *wp, linenr_T lnum, synstate_T *last_valid);
  static int syn_match_linecont(linenr_T lnum);
  static void syn_start_line(void);
  static void syn_update_ends(int startofline);
  static void syn_stack_alloc(void);
  static int syn_stack_cleanup(void);
  static void syn_stack_free_entry(synblock_T *block, synstate_T *p);
  static synstate_T *syn_stack_find_entry(linenr_T lnum);
  static synstate_T *store_current_state(void);
  static void load_current_state(synstate_T *from);
  static void invalidate_current_state(void);
  static int syn_stack_equal(synstate_T *sp);
  static void validate_current_state(void);
  static int syn_finish_line(int syncing);
  static int syn_current_attr(int syncing, int displaying, int *can_spell, int keep_state);
  static int did_match_already(int idx, garray_T *gap);
  static stateitem_T *push_next_match(stateitem_T *cur_si);
  static void check_state_ends(void);
  static void update_si_attr(int idx);
  static void check_keepend(void);
  static void update_si_end(stateitem_T *sip, int startcol, int force);
  static short *copy_id_list(short *list);
  static int in_id_list(stateitem_T *item, short *cont_list, struct sp_syn *ssp, int contained);
  static int push_current_state(int idx);
  static void pop_current_state(void);
  #ifdef FEAT_PROFILE
  static void syn_clear_time(syn_time_T *tt);
  static void syntime_clear(void);
  static void syntime_report(void);
  static int syn_time_on = FALSE;
  # define IF_SYN_TIME(p) (p)
  #else
  # define IF_SYN_TIME(p) NULL
  typedef int syn_time_T;
  #endif
  
  static void syn_stack_apply_changes_block(synblock_T *block, buf_T *buf);
  static void find_endpos(int idx, lpos_T *startpos, lpos_T *m_endpos, lpos_T *hl_endpos, long *flagsp, lpos_T *end_endpos, int *end_idx, reg_extmatch_T *start_ext);
  
  static void limit_pos(lpos_T *pos, lpos_T *limit);
  static void limit_pos_zero(lpos_T *pos, lpos_T *limit);
  static void syn_add_end_off(lpos_T *result, regmmatch_T *regmatch, synpat_T *spp, int idx, int extra);
  static void syn_add_start_off(lpos_T *result, regmmatch_T *regmatch, synpat_T *spp, int idx, int extra);
  static char_u *syn_getcurline(void);
  static int syn_regexec(regmmatch_T *rmp, linenr_T lnum, colnr_T col, syn_time_T *st);
  static int check_keyword_id(char_u *line, int startcol, int *endcol, long *flags, short **next_list, stateitem_T *cur_si, int *ccharp);
  static void syn_remove_pattern(synblock_T *block, int idx);
  static void syn_clear_pattern(synblock_T *block, int i);
  static void syn_clear_cluster(synblock_T *block, int i);
  static void syn_clear_one(int id, int syncing);
  static void syn_cmd_onoff(exarg_T *eap, char *name);
  static void syn_lines_msg(void);
  static void syn_match_msg(void);
  static void syn_list_one(int id, int syncing, int link_only);
  static void syn_list_cluster(int id);
  static void put_id_list(char_u *name, short *list, int attr);
  static void put_pattern(char *s, int c, synpat_T *spp, int attr);
  static int syn_list_keywords(int id, hashtab_T *ht, int did_header, int attr);
  static void syn_clear_keyword(int id, hashtab_T *ht);
  static void clear_keywtab(hashtab_T *ht);
  static int syn_scl_namen2id(char_u *linep, int len);
  static int syn_check_cluster(char_u *pp, int len);
  static int syn_add_cluster(char_u *name);
  static void init_syn_patterns(void);
  static char_u *get_syn_pattern(char_u *arg, synpat_T *ci);
  static int get_id_list(char_u **arg, int keylen, short **list, int skip);
  static void syn_combine_list(short **clstr1, short **clstr2, int list_op);
  
  #if defined(FEAT_RELTIME) || defined(PROTO)
  /*
   * Set the timeout used for syntax highlighting.
   * Use NULL to reset, no timeout.
   */
      void
  syn_set_timeout(proftime_T *tm)
  {
      syn_tm = tm;
  }
  #endif
  
  /*
   * Start the syntax recognition for a line.  This function is normally called
   * from the screen updating, once for each displayed line.
   * The buffer is remembered in syn_buf, because get_syntax_attr() doesn't get
   * it.	Careful: curbuf and curwin are likely to point to another buffer and
   * window.
   */
      void
  syntax_start(win_T *wp, linenr_T lnum)
  {
      synstate_T	*p;
      synstate_T	*last_valid = NULL;
      synstate_T	*last_min_valid = NULL;
      synstate_T	*sp, *prev = NULL;
      linenr_T	parsed_lnum;
      linenr_T	first_stored;
      int		dist;
      static varnumber_T changedtick = 0;	// remember the last change ID
  
  #ifdef FEAT_CONCEAL
      current_sub_char = NUL;
  #endif
  
      /*
       * After switching buffers, invalidate current_state.
       * Also do this when a change was made, the current state may be invalid
       * then.
       */
      if (syn_block != wp->w_s
  	    || syn_buf != wp->w_buffer
  	    || changedtick != CHANGEDTICK(syn_buf))
      {
  	invalidate_current_state();
  	syn_buf = wp->w_buffer;
  	syn_block = wp->w_s;
      }
      changedtick = CHANGEDTICK(syn_buf);
      syn_win = wp;
  
      /*
       * Allocate syntax stack when needed.
       */
      syn_stack_alloc();
      if (syn_block->b_sst_array == NULL)
  	return;		// out of memory
      syn_block->b_sst_lasttick = display_tick;
  
      /*
       * If the state of the end of the previous line is useful, store it.
       */
      if (VALID_STATE(&current_state)
  	    && current_lnum < lnum
  	    && current_lnum < syn_buf->b_ml.ml_line_count)
      {
  	(void)syn_finish_line(FALSE);
  	if (!current_state_stored)
  	{
  	    ++current_lnum;
  	    (void)store_current_state();
  	}
  
  	/*
  	 * If the current_lnum is now the same as "lnum", keep the current
  	 * state (this happens very often!).  Otherwise invalidate
  	 * current_state and figure it out below.
  	 */
  	if (current_lnum != lnum)
  	    invalidate_current_state();
      }
      else
  	invalidate_current_state();
  
      /*
       * Try to synchronize from a saved state in b_sst_array[].
       * Only do this if lnum is not before and not to far beyond a saved state.
       */
      if (INVALID_STATE(&current_state) && syn_block->b_sst_array != NULL)
      {
  	// Find last valid saved state before start_lnum.
  	FOR_ALL_SYNSTATES(syn_block, p)
  	{
  	    if (p->sst_lnum > lnum)
  		break;
  	    if (p->sst_lnum <= lnum && p->sst_change_lnum == 0)
  	    {
  		last_valid = p;
  		if (p->sst_lnum >= lnum - syn_block->b_syn_sync_minlines)
  		    last_min_valid = p;
  	    }
  	}
  	if (last_min_valid != NULL)
  	    load_current_state(last_min_valid);
      }
  
      /*
       * If "lnum" is before or far beyond a line with a saved state, need to
       * re-synchronize.
       */
      if (INVALID_STATE(&current_state))
      {
  	syn_sync(wp, lnum, last_valid);
  	if (current_lnum == 1)
  	    // First line is always valid, no matter "minlines".
  	    first_stored = 1;
  	else
  	    // Need to parse "minlines" lines before state can be considered
  	    // valid to store.
  	    first_stored = current_lnum + syn_block->b_syn_sync_minlines;
      }
      else
  	first_stored = current_lnum;
  
      /*
       * Advance from the sync point or saved state until the current line.
       * Save some entries for syncing with later on.
       */
      if (syn_block->b_sst_len <= Rows)
  	dist = 999999;
      else
  	dist = syn_buf->b_ml.ml_line_count / (syn_block->b_sst_len - Rows) + 1;
      while (current_lnum < lnum)
      {
  	syn_start_line();
  	(void)syn_finish_line(FALSE);
  	++current_lnum;
  
  	// If we parsed at least "minlines" lines or started at a valid
  	// state, the current state is considered valid.
  	if (current_lnum >= first_stored)
  	{
  	    // Check if the saved state entry is for the current line and is
  	    // equal to the current state.  If so, then validate all saved
  	    // states that depended on a change before the parsed line.
  	    if (prev == NULL)
  		prev = syn_stack_find_entry(current_lnum - 1);
  	    if (prev == NULL)
  		sp = syn_block->b_sst_first;
  	    else
  		sp = prev;
  	    while (sp != NULL && sp->sst_lnum < current_lnum)
  		sp = sp->sst_next;
  	    if (sp != NULL
  		    && sp->sst_lnum == current_lnum
  		    && syn_stack_equal(sp))
  	    {
  		parsed_lnum = current_lnum;
  		prev = sp;
  		while (sp != NULL && sp->sst_change_lnum <= parsed_lnum)
  		{
  		    if (sp->sst_lnum <= lnum)
  			// valid state before desired line, use this one
  			prev = sp;
  		    else if (sp->sst_change_lnum == 0)
  			// past saved states depending on change, break here.
  			break;
  		    sp->sst_change_lnum = 0;
  		    sp = sp->sst_next;
  		}
  		load_current_state(prev);
  	    }
  	    // Store the state at this line when it's the first one, the line
  	    // where we start parsing, or some distance from the previously
  	    // saved state.  But only when parsed at least 'minlines'.
  	    else if (prev == NULL
  			|| current_lnum == lnum
  			|| current_lnum >= prev->sst_lnum + dist)
  		prev = store_current_state();
  	}
  
  	// This can take a long time: break when CTRL-C pressed.  The current
  	// state will be wrong then.
  	line_breakcheck();
  	if (got_int)
  	{
  	    current_lnum = lnum;
  	    break;
  	}
      }
  
      syn_start_line();
  }
  
  /*
   * We cannot simply discard growarrays full of state_items or buf_states; we
   * have to manually release their extmatch pointers first.
   */
      static void
  clear_syn_state(synstate_T *p)
  {
      int		i;
      garray_T	*gap;
  
      if (p->sst_stacksize > SST_FIX_STATES)
      {
  	gap = &(p->sst_union.sst_ga);
  	for (i = 0; i < gap->ga_len; i++)
  	    unref_extmatch(SYN_STATE_P(gap)[i].bs_extmatch);
  	ga_clear(gap);
      }
      else
      {
  	for (i = 0; i < p->sst_stacksize; i++)
  	    unref_extmatch(p->sst_union.sst_stack[i].bs_extmatch);
      }
  }
  
  /*
   * Cleanup the current_state stack.
   */
      static void
  clear_current_state(void)
  {
      int		i;
      stateitem_T	*sip;
  
      sip = (stateitem_T *)(current_state.ga_data);
      for (i = 0; i < current_state.ga_len; i++)
  	unref_extmatch(sip[i].si_extmatch);
      ga_clear(&current_state);
  }
  
  /*
   * Try to find a synchronisation point for line "lnum".
   *
   * This sets current_lnum and the current state.  One of three methods is
   * used:
   * 1. Search backwards for the end of a C-comment.
   * 2. Search backwards for given sync patterns.
   * 3. Simply start on a given number of lines above "lnum".
   */
      static void
  syn_sync(
      win_T	*wp,
      linenr_T	start_lnum,
      synstate_T	*last_valid)
  {
      buf_T	*curbuf_save;
      win_T	*curwin_save;
      pos_T	cursor_save;
      int		idx;
      linenr_T	lnum;
      linenr_T	end_lnum;
      linenr_T	break_lnum;
      int		had_sync_point;
      stateitem_T	*cur_si;
      synpat_T	*spp;
      char_u	*line;
      int		found_flags = 0;
      int		found_match_idx = 0;
      linenr_T	found_current_lnum = 0;
      int		found_current_col= 0;
      lpos_T	found_m_endpos;
      colnr_T	prev_current_col;
  
      /*
       * Clear any current state that might be hanging around.
       */
      invalidate_current_state();
  
      /*
       * Start at least "minlines" back.  Default starting point for parsing is
       * there.
       * Start further back, to avoid that scrolling backwards will result in
       * resyncing for every line.  Now it resyncs only one out of N lines,
       * where N is minlines * 1.5, or minlines * 2 if minlines is small.
       * Watch out for overflow when minlines is MAXLNUM.
       */
      if (syn_block->b_syn_sync_minlines > start_lnum)
  	start_lnum = 1;
      else
      {
  	if (syn_block->b_syn_sync_minlines == 1)
  	    lnum = 1;
  	else if (syn_block->b_syn_sync_minlines < 10)
  	    lnum = syn_block->b_syn_sync_minlines * 2;
  	else
  	    lnum = syn_block->b_syn_sync_minlines * 3 / 2;
  	if (syn_block->b_syn_sync_maxlines != 0
  				     && lnum > syn_block->b_syn_sync_maxlines)
  	    lnum = syn_block->b_syn_sync_maxlines;
  	if (lnum >= start_lnum)
  	    start_lnum = 1;
  	else
  	    start_lnum -= lnum;
      }
      current_lnum = start_lnum;
  
      /*
       * 1. Search backwards for the end of a C-style comment.
       */
      if (syn_block->b_syn_sync_flags & SF_CCOMMENT)
      {
  	// Need to make syn_buf the current buffer for a moment, to be able to
  	// use find_start_comment().
  	curwin_save = curwin;
  	curwin = wp;
  	curbuf_save = curbuf;
  	curbuf = syn_buf;
  
  	/*
  	 * Skip lines that end in a backslash.
  	 */
  	for ( ; start_lnum > 1; --start_lnum)
  	{
  	    line = ml_get(start_lnum - 1);
  	    if (*line == NUL || *(line + STRLEN(line) - 1) != '\\')
  		break;
  	}
  	current_lnum = start_lnum;
  
  	// set cursor to start of search
  	cursor_save = wp->w_cursor;
  	wp->w_cursor.lnum = start_lnum;
  	wp->w_cursor.col = 0;
  
  	/*
  	 * If the line is inside a comment, need to find the syntax item that
  	 * defines the comment.
  	 * Restrict the search for the end of a comment to b_syn_sync_maxlines.
  	 */
  	if (find_start_comment((int)syn_block->b_syn_sync_maxlines) != NULL)
  	{
  	    for (idx = syn_block->b_syn_patterns.ga_len; --idx >= 0; )
  		if (SYN_ITEMS(syn_block)[idx].sp_syn.id
  						   == syn_block->b_syn_sync_id
  			&& SYN_ITEMS(syn_block)[idx].sp_type == SPTYPE_START)
  		{
  		    validate_current_state();
  		    if (push_current_state(idx) == OK)
  			update_si_attr(current_state.ga_len - 1);
  		    break;
  		}
  	}
  
  	// restore cursor and buffer
  	wp->w_cursor = cursor_save;
  	curwin = curwin_save;
  	curbuf = curbuf_save;
      }
  
      /*
       * 2. Search backwards for given sync patterns.
       */
      else if (syn_block->b_syn_sync_flags & SF_MATCH)
      {
  	if (syn_block->b_syn_sync_maxlines != 0
  			       && start_lnum > syn_block->b_syn_sync_maxlines)
  	    break_lnum = start_lnum - syn_block->b_syn_sync_maxlines;
  	else
  	    break_lnum = 0;
  
  	found_m_endpos.lnum = 0;
  	found_m_endpos.col = 0;
  	end_lnum = start_lnum;
  	lnum = start_lnum;
  	while (--lnum > break_lnum)
  	{
  	    // This can take a long time: break when CTRL-C pressed.
  	    line_breakcheck();
  	    if (got_int)
  	    {
  		invalidate_current_state();
  		current_lnum = start_lnum;
  		break;
  	    }
  
  	    // Check if we have run into a valid saved state stack now.
  	    if (last_valid != NULL && lnum == last_valid->sst_lnum)
  	    {
  		load_current_state(last_valid);
  		break;
  	    }
  
  	    /*
  	     * Check if the previous line has the line-continuation pattern.
  	     */
  	    if (lnum > 1 && syn_match_linecont(lnum - 1))
  		continue;
  
  	    /*
  	     * Start with nothing on the state stack
  	     */
  	    validate_current_state();
  
  	    for (current_lnum = lnum; current_lnum < end_lnum; ++current_lnum)
  	    {
  		syn_start_line();
  		for (;;)
  		{
  		    had_sync_point = syn_finish_line(TRUE);
  		    /*
  		     * When a sync point has been found, remember where, and
  		     * continue to look for another one, further on in the line.
  		     */
  		    if (had_sync_point && current_state.ga_len)
  		    {
  			cur_si = &CUR_STATE(current_state.ga_len - 1);
  			if (cur_si->si_m_endpos.lnum > start_lnum)
  			{
  			    // ignore match that goes to after where started
  			    current_lnum = end_lnum;
  			    break;
  			}
  			if (cur_si->si_idx < 0)
  			{
  			    // Cannot happen?
  			    found_flags = 0;
  			    found_match_idx = KEYWORD_IDX;
  			}
  			else
  			{
  			    spp = &(SYN_ITEMS(syn_block)[cur_si->si_idx]);
  			    found_flags = spp->sp_flags;
  			    found_match_idx = spp->sp_sync_idx;
  			}
  			found_current_lnum = current_lnum;
  			found_current_col = current_col;
  			found_m_endpos = cur_si->si_m_endpos;
  			/*
  			 * Continue after the match (be aware of a zero-length
  			 * match).
  			 */
  			if (found_m_endpos.lnum > current_lnum)
  			{
  			    current_lnum = found_m_endpos.lnum;
  			    current_col = found_m_endpos.col;
  			    if (current_lnum >= end_lnum)
  				break;
  			}
  			else if (found_m_endpos.col > current_col)
  			    current_col = found_m_endpos.col;
  			else
  			    ++current_col;
  
  			// syn_current_attr() will have skipped the check for
  			// an item that ends here, need to do that now.  Be
  			// careful not to go past the NUL.
  			prev_current_col = current_col;
  			if (syn_getcurline()[current_col] != NUL)
  			    ++current_col;
  			check_state_ends();
  			current_col = prev_current_col;
  		    }
  		    else
  			break;
  		}
  	    }
  
  	    /*
  	     * If a sync point was encountered, break here.
  	     */
  	    if (found_flags)
  	    {
  		/*
  		 * Put the item that was specified by the sync point on the
  		 * state stack.  If there was no item specified, make the
  		 * state stack empty.
  		 */
  		clear_current_state();
  		if (found_match_idx >= 0
  			&& push_current_state(found_match_idx) == OK)
  		    update_si_attr(current_state.ga_len - 1);
  
  		/*
  		 * When using "grouphere", continue from the sync point
  		 * match, until the end of the line.  Parsing starts at
  		 * the next line.
  		 * For "groupthere" the parsing starts at start_lnum.
  		 */
  		if (found_flags & HL_SYNC_HERE)
  		{
  		    if (current_state.ga_len)
  		    {
  			cur_si = &CUR_STATE(current_state.ga_len - 1);
  			cur_si->si_h_startpos.lnum = found_current_lnum;
  			cur_si->si_h_startpos.col = found_current_col;
  			update_si_end(cur_si, (int)current_col, TRUE);
  			check_keepend();
  		    }
  		    current_col = found_m_endpos.col;
  		    current_lnum = found_m_endpos.lnum;
  		    (void)syn_finish_line(FALSE);
  		    ++current_lnum;
  		}
  		else
  		    current_lnum = start_lnum;
  
  		break;
  	    }
  
  	    end_lnum = lnum;
  	    invalidate_current_state();
  	}
  
  	// Ran into start of the file or exceeded maximum number of lines
  	if (lnum <= break_lnum)
  	{
  	    invalidate_current_state();
  	    current_lnum = break_lnum + 1;
  	}
      }
  
      validate_current_state();
  }
  
      static void
  save_chartab(char_u *chartab)
  {
      if (syn_block->b_syn_isk != empty_option)
      {
  	mch_memmove(chartab, syn_buf->b_chartab, (size_t)32);
  	mch_memmove(syn_buf->b_chartab, syn_win->w_s->b_syn_chartab,
  								  (size_t)32);
      }
  }
  
      static void
  restore_chartab(char_u *chartab)
  {
      if (syn_win->w_s->b_syn_isk != empty_option)
  	mch_memmove(syn_buf->b_chartab, chartab, (size_t)32);
  }
  
  /*
   * Return TRUE if the line-continuation pattern matches in line "lnum".
   */
      static int
  syn_match_linecont(linenr_T lnum)
  {
      regmmatch_T regmatch;
      int r;
      char_u	buf_chartab[32];  // chartab array for syn iskyeyword
  
      if (syn_block->b_syn_linecont_prog != NULL)
      {
  	// use syntax iskeyword option
  	save_chartab(buf_chartab);
  	regmatch.rmm_ic = syn_block->b_syn_linecont_ic;
  	regmatch.regprog = syn_block->b_syn_linecont_prog;
  	r = syn_regexec(&regmatch, lnum, (colnr_T)0,
  				IF_SYN_TIME(&syn_block->b_syn_linecont_time));
  	syn_block->b_syn_linecont_prog = regmatch.regprog;
  	restore_chartab(buf_chartab);
  	return r;
      }
      return FALSE;
  }
  
  /*
   * Prepare the current state for the start of a line.
   */
      static void
  syn_start_line(void)
  {
      current_finished = FALSE;
      current_col = 0;
  
      /*
       * Need to update the end of a start/skip/end that continues from the
       * previous line and regions that have "keepend".
       */
      if (current_state.ga_len > 0)
      {
  	syn_update_ends(TRUE);
  	check_state_ends();
      }
  
      next_match_idx = -1;
      ++current_line_id;
  #ifdef FEAT_CONCEAL
      next_seqnr = 1;
  #endif
  }
  
  /*
   * Check for items in the stack that need their end updated.
   * When "startofline" is TRUE the last item is always updated.
   * When "startofline" is FALSE the item with "keepend" is forcefully updated.
   */
      static void
  syn_update_ends(int startofline)
  {
      stateitem_T	*cur_si;
      int		i;
      int		seen_keepend;
  
      if (startofline)
      {
  	// Check for a match carried over from a previous line with a
  	// contained region.  The match ends as soon as the region ends.
  	for (i = 0; i < current_state.ga_len; ++i)
  	{
  	    cur_si = &CUR_STATE(i);
  	    if (cur_si->si_idx >= 0
  		    && (SYN_ITEMS(syn_block)[cur_si->si_idx]).sp_type
  							       == SPTYPE_MATCH
  		    && cur_si->si_m_endpos.lnum < current_lnum)
  	    {
  		cur_si->si_flags |= HL_MATCHCONT;
  		cur_si->si_m_endpos.lnum = 0;
  		cur_si->si_m_endpos.col = 0;
  		cur_si->si_h_endpos = cur_si->si_m_endpos;
  		cur_si->si_ends = TRUE;
  	    }
  	}
      }
  
      /*
       * Need to update the end of a start/skip/end that continues from the
       * previous line.  And regions that have "keepend", because they may
       * influence contained items.  If we've just removed "extend"
       * (startofline == 0) then we should update ends of normal regions
       * contained inside "keepend" because "extend" could have extended
       * these "keepend" regions as well as contained normal regions.
       * Then check for items ending in column 0.
       */
      i = current_state.ga_len - 1;
      if (keepend_level >= 0)
  	for ( ; i > keepend_level; --i)
  	    if (CUR_STATE(i).si_flags & HL_EXTEND)
  		break;
  
      seen_keepend = FALSE;
      for ( ; i < current_state.ga_len; ++i)
      {
  	cur_si = &CUR_STATE(i);
  	if ((cur_si->si_flags & HL_KEEPEND)
  			    || (seen_keepend && !startofline)
  			    || (i == current_state.ga_len - 1 && startofline))
  	{
  	    cur_si->si_h_startpos.col = 0;	// start highl. in col 0
  	    cur_si->si_h_startpos.lnum = current_lnum;
  
  	    if (!(cur_si->si_flags & HL_MATCHCONT))
  		update_si_end(cur_si, (int)current_col, !startofline);
  
  	    if (!startofline && (cur_si->si_flags & HL_KEEPEND))
  		seen_keepend = TRUE;
  	}
      }
      check_keepend();
  }
  
  /////////////////////////////////////////
  // Handling of the state stack cache.
  
  /*
   * EXPLANATION OF THE SYNTAX STATE STACK CACHE
   *
   * To speed up syntax highlighting, the state stack for the start of some
   * lines is cached.  These entries can be used to start parsing at that point.
   *
   * The stack is kept in b_sst_array[] for each buffer.  There is a list of
   * valid entries.  b_sst_first points to the first one, then follow sst_next.
   * The entries are sorted on line number.  The first entry is often for line 2
   * (line 1 always starts with an empty stack).
   * There is also a list for free entries.  This construction is used to avoid
   * having to allocate and free memory blocks too often.
   *
   * When making changes to the buffer, this is logged in b_mod_*.  When calling
   * update_screen() to update the display, it will call
   * syn_stack_apply_changes() for each displayed buffer to adjust the cached
   * entries.  The entries which are inside the changed area are removed,
   * because they must be recomputed.  Entries below the changed have their line
   * number adjusted for deleted/inserted lines, and have their sst_change_lnum
   * set to indicate that a check must be made if the changed lines would change
   * the cached entry.
   *
   * When later displaying lines, an entry is stored for each line.  Displayed
   * lines are likely to be displayed again, in which case the state at the
   * start of the line is needed.
   * For not displayed lines, an entry is stored for every so many lines.  These
   * entries will be used e.g., when scrolling backwards.  The distance between
   * entries depends on the number of lines in the buffer.  For small buffers
   * the distance is fixed at SST_DIST, for large buffers there is a fixed
   * number of entries SST_MAX_ENTRIES, and the distance is computed.
   */
  
      static void
  syn_stack_free_block(synblock_T *block)
  {
      synstate_T	*p;
  
      if (block->b_sst_array != NULL)
      {
  	FOR_ALL_SYNSTATES(block, p)
  	    clear_syn_state(p);
  	VIM_CLEAR(block->b_sst_array);
  	block->b_sst_first = NULL;
  	block->b_sst_len = 0;
      }
  }
  /*
   * Free b_sst_array[] for buffer "buf".
   * Used when syntax items changed to force resyncing everywhere.
   */
      void
  syn_stack_free_all(synblock_T *block)
  {
  #ifdef FEAT_FOLDING
      win_T	*wp;
  #endif
  
      syn_stack_free_block(block);
  
  #ifdef FEAT_FOLDING
      // When using "syntax" fold method, must update all folds.
      FOR_ALL_WINDOWS(wp)
      {
  	if (wp->w_s == block && foldmethodIsSyntax(wp))
  	    foldUpdateAll(wp);
      }
  #endif
  }
  
  /*
   * Allocate the syntax state stack for syn_buf when needed.
   * If the number of entries in b_sst_array[] is much too big or a bit too
   * small, reallocate it.
   * Also used to allocate b_sst_array[] for the first time.
   */
      static void
  syn_stack_alloc(void)
  {
      long	len;
      synstate_T	*to, *from;
      synstate_T	*sstp;
  
      len = syn_buf->b_ml.ml_line_count / SST_DIST + Rows * 2;
      if (len < SST_MIN_ENTRIES)
  	len = SST_MIN_ENTRIES;
      else if (len > SST_MAX_ENTRIES)
  	len = SST_MAX_ENTRIES;
      if (syn_block->b_sst_len > len * 2 || syn_block->b_sst_len < len)
      {
  	// Allocate 50% too much, to avoid reallocating too often.
  	len = syn_buf->b_ml.ml_line_count;
  	len = (len + len / 2) / SST_DIST + Rows * 2;
  	if (len < SST_MIN_ENTRIES)
  	    len = SST_MIN_ENTRIES;
  	else if (len > SST_MAX_ENTRIES)
  	    len = SST_MAX_ENTRIES;
  
  	if (syn_block->b_sst_array != NULL)
  	{
  	    // When shrinking the array, cleanup the existing stack.
  	    // Make sure that all valid entries fit in the new array.
  	    while (syn_block->b_sst_len - syn_block->b_sst_freecount + 2 > len
  		    && syn_stack_cleanup())
  		;
  	    if (len < syn_block->b_sst_len - syn_block->b_sst_freecount + 2)
  		len = syn_block->b_sst_len - syn_block->b_sst_freecount + 2;
  	}
  
  	sstp = ALLOC_CLEAR_MULT(synstate_T, len);
  	if (sstp == NULL)	// out of memory!
  	    return;
  
  	to = sstp - 1;
  	if (syn_block->b_sst_array != NULL)
  	{
  	    // Move the states from the old array to the new one.
  	    for (from = syn_block->b_sst_first; from != NULL;
  							from = from->sst_next)
  	    {
  		++to;
  		*to = *from;
  		to->sst_next = to + 1;
  	    }
  	}
  	if (to != sstp - 1)
  	{
  	    to->sst_next = NULL;
  	    syn_block->b_sst_first = sstp;
  	    syn_block->b_sst_freecount = len - (int)(to - sstp) - 1;
  	}
  	else
  	{
  	    syn_block->b_sst_first = NULL;
  	    syn_block->b_sst_freecount = len;
  	}
  
  	// Create the list of free entries.
  	syn_block->b_sst_firstfree = to + 1;
  	while (++to < sstp + len)
  	    to->sst_next = to + 1;
  	(sstp + len - 1)->sst_next = NULL;
  
  	vim_free(syn_block->b_sst_array);
  	syn_block->b_sst_array = sstp;
  	syn_block->b_sst_len = len;
      }
  }
  
  /*
   * Check for changes in a buffer to affect stored syntax states.  Uses the
   * b_mod_* fields.
   * Called from update_screen(), before screen is being updated, once for each
   * displayed buffer.
   */
      void
  syn_stack_apply_changes(buf_T *buf)
  {
      win_T	*wp;
  
      syn_stack_apply_changes_block(&buf->b_s, buf);
  
      FOR_ALL_WINDOWS(wp)
      {
  	if ((wp->w_buffer == buf) && (wp->w_s != &buf->b_s))
  	    syn_stack_apply_changes_block(wp->w_s, buf);
      }
  }
  
      static void
  syn_stack_apply_changes_block(synblock_T *block, buf_T *buf)
  {
      synstate_T	*p, *prev, *np;
      linenr_T	n;
  
      prev = NULL;
      for (p = block->b_sst_first; p != NULL; )
      {
  	if (p->sst_lnum + block->b_syn_sync_linebreaks > buf->b_mod_top)
  	{
  	    n = p->sst_lnum + buf->b_mod_xlines;
  	    if (n <= buf->b_mod_bot)
  	    {
  		// this state is inside the changed area, remove it
  		np = p->sst_next;
  		if (prev == NULL)
  		    block->b_sst_first = np;
  		else
  		    prev->sst_next = np;
  		syn_stack_free_entry(block, p);
  		p = np;
  		continue;
  	    }
  	    // This state is below the changed area.  Remember the line
  	    // that needs to be parsed before this entry can be made valid
  	    // again.
  	    if (p->sst_change_lnum != 0 && p->sst_change_lnum > buf->b_mod_top)
  	    {
  		if (p->sst_change_lnum + buf->b_mod_xlines > buf->b_mod_top)
  		    p->sst_change_lnum += buf->b_mod_xlines;
  		else
  		    p->sst_change_lnum = buf->b_mod_top;
  	    }
  	    if (p->sst_change_lnum == 0
  		    || p->sst_change_lnum < buf->b_mod_bot)
  		p->sst_change_lnum = buf->b_mod_bot;
  
  	    p->sst_lnum = n;
  	}
  	prev = p;
  	p = p->sst_next;
      }
  }
  
  /*
   * Reduce the number of entries in the state stack for syn_buf.
   * Returns TRUE if at least one entry was freed.
   */
      static int
  syn_stack_cleanup(void)
  {
      synstate_T	*p, *prev;
      disptick_T	tick;
      int		above;
      int		dist;
      int		retval = FALSE;
  
      if (syn_block->b_sst_first == NULL)
  	return retval;
  
      // Compute normal distance between non-displayed entries.
      if (syn_block->b_sst_len <= Rows)
  	dist = 999999;
      else
  	dist = syn_buf->b_ml.ml_line_count / (syn_block->b_sst_len - Rows) + 1;
  
      /*
       * Go through the list to find the "tick" for the oldest entry that can
       * be removed.  Set "above" when the "tick" for the oldest entry is above
       * "b_sst_lasttick" (the display tick wraps around).
       */
      tick = syn_block->b_sst_lasttick;
      above = FALSE;
      prev = syn_block->b_sst_first;
      for (p = prev->sst_next; p != NULL; prev = p, p = p->sst_next)
      {
  	if (prev->sst_lnum + dist > p->sst_lnum)
  	{
  	    if (p->sst_tick > syn_block->b_sst_lasttick)
  	    {
  		if (!above || p->sst_tick < tick)
  		    tick = p->sst_tick;
  		above = TRUE;
  	    }
  	    else if (!above && p->sst_tick < tick)
  		tick = p->sst_tick;
  	}
      }
  
      /*
       * Go through the list to make the entries for the oldest tick at an
       * interval of several lines.
       */
      prev = syn_block->b_sst_first;
      for (p = prev->sst_next; p != NULL; prev = p, p = p->sst_next)
      {
  	if (p->sst_tick == tick && prev->sst_lnum + dist > p->sst_lnum)
  	{
  	    // Move this entry from used list to free list
  	    prev->sst_next = p->sst_next;
  	    syn_stack_free_entry(syn_block, p);
  	    p = prev;
  	    retval = TRUE;
  	}
      }
      return retval;
  }
  
  /*
   * Free the allocated memory for a syn_state item.
   * Move the entry into the free list.
   */
      static void
  syn_stack_free_entry(synblock_T *block, synstate_T *p)
  {
      clear_syn_state(p);
      p->sst_next = block->b_sst_firstfree;
      block->b_sst_firstfree = p;
      ++block->b_sst_freecount;
  }
  
  /*
   * Find an entry in the list of state stacks at or before "lnum".
   * Returns NULL when there is no entry or the first entry is after "lnum".
   */
      static synstate_T *
  syn_stack_find_entry(linenr_T lnum)
  {
      synstate_T	*p, *prev;
  
      prev = NULL;
      for (p = syn_block->b_sst_first; p != NULL; prev = p, p = p->sst_next)
      {
  	if (p->sst_lnum == lnum)
  	    return p;
  	if (p->sst_lnum > lnum)
  	    break;
      }
      return prev;
  }
  
  /*
   * Try saving the current state in b_sst_array[].
   * The current state must be valid for the start of the current_lnum line!
   */
      static synstate_T *
  store_current_state(void)
  {
      int		i;
      synstate_T	*p;
      bufstate_T	*bp;
      stateitem_T	*cur_si;
      synstate_T	*sp = syn_stack_find_entry(current_lnum);
  
      /*
       * If the current state contains a start or end pattern that continues
       * from the previous line, we can't use it.  Don't store it then.
       */
      for (i = current_state.ga_len - 1; i >= 0; --i)
      {
  	cur_si = &CUR_STATE(i);
  	if (cur_si->si_h_startpos.lnum >= current_lnum
  		|| cur_si->si_m_endpos.lnum >= current_lnum
  		|| cur_si->si_h_endpos.lnum >= current_lnum
  		|| (cur_si->si_end_idx
  		    && cur_si->si_eoe_pos.lnum >= current_lnum))
  	    break;
      }
      if (i >= 0)
      {
  	if (sp != NULL)
  	{
  	    // find "sp" in the list and remove it
  	    if (syn_block->b_sst_first == sp)
  		// it's the first entry
  		syn_block->b_sst_first = sp->sst_next;
  	    else
  	    {
  		// find the entry just before this one to adjust sst_next
  		FOR_ALL_SYNSTATES(syn_block, p)
  		    if (p->sst_next == sp)
  			break;
  		if (p != NULL)	// just in case
  		    p->sst_next = sp->sst_next;
  	    }
  	    syn_stack_free_entry(syn_block, sp);
  	    sp = NULL;
  	}
      }
      else if (sp == NULL || sp->sst_lnum != current_lnum)
      {
  	/*
  	 * Add a new entry
  	 */
  	// If no free items, cleanup the array first.
  	if (syn_block->b_sst_freecount == 0)
  	{
  	    (void)syn_stack_cleanup();
  	    // "sp" may have been moved to the freelist now
  	    sp = syn_stack_find_entry(current_lnum);
  	}
  	// Still no free items?  Must be a strange problem...
  	if (syn_block->b_sst_freecount == 0)
  	    sp = NULL;
  	else
  	{
  	    // Take the first item from the free list and put it in the used
  	    // list, after *sp
  	    p = syn_block->b_sst_firstfree;
  	    syn_block->b_sst_firstfree = p->sst_next;
  	    --syn_block->b_sst_freecount;
  	    if (sp == NULL)
  	    {
  		// Insert in front of the list
  		p->sst_next = syn_block->b_sst_first;
  		syn_block->b_sst_first = p;
  	    }
  	    else
  	    {
  		// insert in list after *sp
  		p->sst_next = sp->sst_next;
  		sp->sst_next = p;
  	    }
  	    sp = p;
  	    sp->sst_stacksize = 0;
  	    sp->sst_lnum = current_lnum;
  	}
      }
      if (sp != NULL)
      {
  	// When overwriting an existing state stack, clear it first
  	clear_syn_state(sp);
  	sp->sst_stacksize = current_state.ga_len;
  	if (current_state.ga_len > SST_FIX_STATES)
  	{
  	    // Need to clear it, might be something remaining from when the
  	    // length was less than SST_FIX_STATES.
  	    ga_init2(&sp->sst_union.sst_ga, (int)sizeof(bufstate_T), 1);
  	    if (ga_grow(&sp->sst_union.sst_ga, current_state.ga_len) == FAIL)
  		sp->sst_stacksize = 0;
  	    else
  		sp->sst_union.sst_ga.ga_len = current_state.ga_len;
  	    bp = SYN_STATE_P(&(sp->sst_union.sst_ga));
  	}
  	else
  	    bp = sp->sst_union.sst_stack;
  	for (i = 0; i < sp->sst_stacksize; ++i)
  	{
  	    bp[i].bs_idx = CUR_STATE(i).si_idx;
  	    bp[i].bs_flags = CUR_STATE(i).si_flags;
  #ifdef FEAT_CONCEAL
  	    bp[i].bs_seqnr = CUR_STATE(i).si_seqnr;
  	    bp[i].bs_cchar = CUR_STATE(i).si_cchar;
  #endif
  	    bp[i].bs_extmatch = ref_extmatch(CUR_STATE(i).si_extmatch);
  	}
  	sp->sst_next_flags = current_next_flags;
  	sp->sst_next_list = current_next_list;
  	sp->sst_tick = display_tick;
  	sp->sst_change_lnum = 0;
      }
      current_state_stored = TRUE;
      return sp;
  }
  
  /*
   * Copy a state stack from "from" in b_sst_array[] to current_state;
   */
      static void
  load_current_state(synstate_T *from)
  {
      int		i;
      bufstate_T	*bp;
  
      clear_current_state();
      validate_current_state();
      keepend_level = -1;
      if (from->sst_stacksize
  	    && ga_grow(&current_state, from->sst_stacksize) != FAIL)
      {
  	if (from->sst_stacksize > SST_FIX_STATES)
  	    bp = SYN_STATE_P(&(from->sst_union.sst_ga));
  	else
  	    bp = from->sst_union.sst_stack;
  	for (i = 0; i < from->sst_stacksize; ++i)
  	{
  	    CUR_STATE(i).si_idx = bp[i].bs_idx;
  	    CUR_STATE(i).si_flags = bp[i].bs_flags;
  #ifdef FEAT_CONCEAL
  	    CUR_STATE(i).si_seqnr = bp[i].bs_seqnr;
  	    CUR_STATE(i).si_cchar = bp[i].bs_cchar;
  #endif
  	    CUR_STATE(i).si_extmatch = ref_extmatch(bp[i].bs_extmatch);
  	    if (keepend_level < 0 && (CUR_STATE(i).si_flags & HL_KEEPEND))
  		keepend_level = i;
  	    CUR_STATE(i).si_ends = FALSE;
  	    CUR_STATE(i).si_m_lnum = 0;
  	    if (CUR_STATE(i).si_idx >= 0)
  		CUR_STATE(i).si_next_list =
  		     (SYN_ITEMS(syn_block)[CUR_STATE(i).si_idx]).sp_next_list;
  	    else
  		CUR_STATE(i).si_next_list = NULL;
  	    update_si_attr(i);
  	}
  	current_state.ga_len = from->sst_stacksize;
      }
      current_next_list = from->sst_next_list;
      current_next_flags = from->sst_next_flags;
      current_lnum = from->sst_lnum;
  }
  
  /*
   * Compare saved state stack "*sp" with the current state.
   * Return TRUE when they are equal.
   */
      static int
  syn_stack_equal(synstate_T *sp)
  {
      int		i, j;
      bufstate_T	*bp;
      reg_extmatch_T	*six, *bsx;
  
      // First a quick check if the stacks have the same size end nextlist.
      if (sp->sst_stacksize == current_state.ga_len
  	    && sp->sst_next_list == current_next_list)
      {
  	// Need to compare all states on both stacks.
  	if (sp->sst_stacksize > SST_FIX_STATES)
  	    bp = SYN_STATE_P(&(sp->sst_union.sst_ga));
  	else
  	    bp = sp->sst_union.sst_stack;
  
  	for (i = current_state.ga_len; --i >= 0; )
  	{
  	    // If the item has another index the state is different.
  	    if (bp[i].bs_idx != CUR_STATE(i).si_idx)
  		break;
  	    if (bp[i].bs_extmatch != CUR_STATE(i).si_extmatch)
  	    {
  		// When the extmatch pointers are different, the strings in
  		// them can still be the same.  Check if the extmatch
  		// references are equal.
  		bsx = bp[i].bs_extmatch;
  		six = CUR_STATE(i).si_extmatch;
  		// If one of the extmatch pointers is NULL the states are
  		// different.
  		if (bsx == NULL || six == NULL)
  		    break;
  		for (j = 0; j < NSUBEXP; ++j)
  		{
  		    // Check each referenced match string. They must all be
  		    // equal.
  		    if (bsx->matches[j] != six->matches[j])
  		    {
  			// If the pointer is different it can still be the
  			// same text.  Compare the strings, ignore case when
  			// the start item has the sp_ic flag set.
  			if (bsx->matches[j] == NULL
  				|| six->matches[j] == NULL)
  			    break;
  			if ((SYN_ITEMS(syn_block)[CUR_STATE(i).si_idx]).sp_ic
  				? MB_STRICMP(bsx->matches[j],
  							 six->matches[j]) != 0
  				: STRCMP(bsx->matches[j], six->matches[j]) != 0)
  			    break;
  		    }
  		}
  		if (j != NSUBEXP)
  		    break;
  	    }
  	}
  	if (i < 0)
  	    return TRUE;
      }
      return FALSE;
  }
  
  /*
   * We stop parsing syntax above line "lnum".  If the stored state at or below
   * this line depended on a change before it, it now depends on the line below
   * the last parsed line.
   * The window looks like this:
   *	    line which changed
   *	    displayed line
   *	    displayed line
   * lnum ->  line below window
   */
      void
  syntax_end_parsing(linenr_T lnum)
  {
      synstate_T	*sp;
  
      sp = syn_stack_find_entry(lnum);
      if (sp != NULL && sp->sst_lnum < lnum)
  	sp = sp->sst_next;
  
      if (sp != NULL && sp->sst_change_lnum != 0)
  	sp->sst_change_lnum = lnum;
  }
  
  /*
   * End of handling of the state stack.
   ****************************************/
  
      static void
  invalidate_current_state(void)
  {
      clear_current_state();
      current_state.ga_itemsize = 0;	// mark current_state invalid
      current_next_list = NULL;
      keepend_level = -1;
  }
  
      static void
  validate_current_state(void)
  {
      current_state.ga_itemsize = sizeof(stateitem_T);
      current_state.ga_growsize = 3;
  }
  
  /*
   * Return TRUE if the syntax at start of lnum changed since last time.
   * This will only be called just after get_syntax_attr() for the previous
   * line, to check if the next line needs to be redrawn too.
   */
      int
  syntax_check_changed(linenr_T lnum)
  {
      int		retval = TRUE;
      synstate_T	*sp;
  
      /*
       * Check the state stack when:
       * - lnum is just below the previously syntaxed line.
       * - lnum is not before the lines with saved states.
       * - lnum is not past the lines with saved states.
       * - lnum is at or before the last changed line.
       */
      if (VALID_STATE(&current_state) && lnum == current_lnum + 1)
      {
  	sp = syn_stack_find_entry(lnum);
  	if (sp != NULL && sp->sst_lnum == lnum)
  	{
  	    /*
  	     * finish the previous line (needed when not all of the line was
  	     * drawn)
  	     */
  	    (void)syn_finish_line(FALSE);
  
  	    /*
  	     * Compare the current state with the previously saved state of
  	     * the line.
  	     */
  	    if (syn_stack_equal(sp))
  		retval = FALSE;
  
  	    /*
  	     * Store the current state in b_sst_array[] for later use.
  	     */
  	    ++current_lnum;
  	    (void)store_current_state();
  	}
      }
  
      return retval;
  }
  
  /*
   * Finish the current line.
   * This doesn't return any attributes, it only gets the state at the end of
   * the line.  It can start anywhere in the line, as long as the current state
   * is valid.
   */
      static int
  syn_finish_line(
      int	    syncing)		// called for syncing
  {
      stateitem_T	*cur_si;
      colnr_T	prev_current_col;
  
      while (!current_finished)
      {
  	(void)syn_current_attr(syncing, FALSE, NULL, FALSE);
  	/*
  	 * When syncing, and found some item, need to check the item.
  	 */
  	if (syncing && current_state.ga_len)
  	{
  	    /*
  	     * Check for match with sync item.
  	     */
  	    cur_si = &CUR_STATE(current_state.ga_len - 1);
  	    if (cur_si->si_idx >= 0
  		    && (SYN_ITEMS(syn_block)[cur_si->si_idx].sp_flags
  					  & (HL_SYNC_HERE|HL_SYNC_THERE)))
  		return TRUE;
  
  	    // syn_current_attr() will have skipped the check for an item
  	    // that ends here, need to do that now.  Be careful not to go
  	    // past the NUL.
  	    prev_current_col = current_col;
  	    if (syn_getcurline()[current_col] != NUL)
  		++current_col;
  	    check_state_ends();
  	    current_col = prev_current_col;
  	}
  	++current_col;
      }
      return FALSE;
  }
  
  /*
   * Return highlight attributes for next character.
   * Must first call syntax_start() once for the line.
   * "col" is normally 0 for the first use in a line, and increments by one each
   * time.  It's allowed to skip characters and to stop before the end of the
   * line.  But only a "col" after a previously used column is allowed.
   * When "can_spell" is not NULL set it to TRUE when spell-checking should be
   * done.
   */
      int
  get_syntax_attr(
      colnr_T	col,
      int		*can_spell,
      int		keep_state)	// keep state of char at "col"
  {
      int	    attr = 0;
  
      if (can_spell != NULL)
  	// Default: Only do spelling when there is no @Spell cluster or when
  	// ":syn spell toplevel" was used.
  	*can_spell = syn_block->b_syn_spell == SYNSPL_DEFAULT
  		    ? (syn_block->b_spell_cluster_id == 0)
  		    : (syn_block->b_syn_spell == SYNSPL_TOP);
  
      // check for out of memory situation
      if (syn_block->b_sst_array == NULL)
  	return 0;
  
      // After 'synmaxcol' the attribute is always zero.
      if (syn_buf->b_p_smc > 0 && col >= (colnr_T)syn_buf->b_p_smc)
      {
  	clear_current_state();
  #ifdef FEAT_EVAL
  	current_id = 0;
  	current_trans_id = 0;
  #endif
  #ifdef FEAT_CONCEAL
  	current_flags = 0;
  	current_seqnr = 0;
  #endif
  	return 0;
      }
  
      // Make sure current_state is valid
      if (INVALID_STATE(&current_state))
  	validate_current_state();
  
      /*
       * Skip from the current column to "col", get the attributes for "col".
       */
      while (current_col <= col)
      {
  	attr = syn_current_attr(FALSE, TRUE, can_spell,
  				     current_col == col ? keep_state : FALSE);
  	++current_col;
      }
  
      return attr;
  }
  
  /*
   * Get syntax attributes for current_lnum, current_col.
   */
      static int
  syn_current_attr(
      int		syncing,		// When 1: called for syncing
      int		displaying,		// result will be displayed
      int		*can_spell,		// return: do spell checking
      int		keep_state)		// keep syntax stack afterwards
  {
      int		syn_id;
      lpos_T	endpos;		// was: char_u *endp;
      lpos_T	hl_startpos;	// was: int hl_startcol;
      lpos_T	hl_endpos;
      lpos_T	eos_pos;	// end-of-start match (start region)
      lpos_T	eoe_pos;	// end-of-end pattern
      int		end_idx;	// group ID for end pattern
      int		idx;
      synpat_T	*spp;
      stateitem_T	*cur_si, *sip = NULL;
      int		startcol;
      int		endcol;
      long	flags;
      int		cchar;
      short	*next_list;
      int		found_match;		    // found usable match
      static int	try_next_column = FALSE;    // must try in next col
      int		do_keywords;
      regmmatch_T	regmatch;
      lpos_T	pos;
      int		lc_col;
      reg_extmatch_T *cur_extmatch = NULL;
      char_u	buf_chartab[32];  // chartab array for syn iskyeyword
      char_u	*line;		// current line.  NOTE: becomes invalid after
  				// looking for a pattern match!
  
      // variables for zero-width matches that have a "nextgroup" argument
      int		keep_next_list;
      int		zero_width_next_list = FALSE;
      garray_T	zero_width_next_ga;
  
      /*
       * No character, no attributes!  Past end of line?
       * Do try matching with an empty line (could be the start of a region).
       */
      line = syn_getcurline();
      if (line[current_col] == NUL && current_col != 0)
      {
  	/*
  	 * If we found a match after the last column, use it.
  	 */
  	if (next_match_idx >= 0 && next_match_col >= (int)current_col
  						  && next_match_col != MAXCOL)
  	    (void)push_next_match(NULL);
  
  	current_finished = TRUE;
  	current_state_stored = FALSE;
  	return 0;
      }
  
      // if the current or next character is NUL, we will finish the line now
      if (line[current_col] == NUL || line[current_col + 1] == NUL)
      {
  	current_finished = TRUE;
  	current_state_stored = FALSE;
      }
  
      /*
       * When in the previous column there was a match but it could not be used
       * (empty match or already matched in this column) need to try again in
       * the next column.
       */
      if (try_next_column)
      {
  	next_match_idx = -1;
  	try_next_column = FALSE;
      }
  
      // Only check for keywords when not syncing and there are some.
      do_keywords = !syncing
  		    && (syn_block->b_keywtab.ht_used > 0
  			    || syn_block->b_keywtab_ic.ht_used > 0);
  
      // Init the list of zero-width matches with a nextlist.  This is used to
      // avoid matching the same item in the same position twice.
      ga_init2(&zero_width_next_ga, (int)sizeof(int), 10);
  
      // use syntax iskeyword option
      save_chartab(buf_chartab);
  
      /*
       * Repeat matching keywords and patterns, to find contained items at the
       * same column.  This stops when there are no extra matches at the current
       * column.
       */
      do
      {
  	found_match = FALSE;
  	keep_next_list = FALSE;
  	syn_id = 0;
  
  
  	/*
  	 * 1. Check for a current state.
  	 *    Only when there is no current state, or if the current state may
  	 *    contain other things, we need to check for keywords and patterns.
  	 *    Always need to check for contained items if some item has the
  	 *    "containedin" argument (takes extra time!).
  	 */
  	if (current_state.ga_len)
  	    cur_si = &CUR_STATE(current_state.ga_len - 1);
  	else
  	    cur_si = NULL;
  
  	if (syn_block->b_syn_containedin || cur_si == NULL
  					      || cur_si->si_cont_list != NULL)
  	{
  	    /*
  	     * 2. Check for keywords, if on a keyword char after a non-keyword
  	     *	  char.  Don't do this when syncing.
  	     */
  	    if (do_keywords)
  	    {
  	      line = syn_getcurline();
  	      if (vim_iswordp_buf(line + current_col, syn_buf)
  		      && (current_col == 0
  			  || !vim_iswordp_buf(line + current_col - 1
  			      - (has_mbyte
  				  ? (*mb_head_off)(line, line + current_col - 1)
  				  : 0) , syn_buf)))
  	      {
  		syn_id = check_keyword_id(line, (int)current_col,
  					 &endcol, &flags, &next_list, cur_si,
  					 &cchar);
  		if (syn_id != 0)
  		{
  		    if (push_current_state(KEYWORD_IDX) == OK)
  		    {
  			cur_si = &CUR_STATE(current_state.ga_len - 1);
  			cur_si->si_m_startcol = current_col;
  			cur_si->si_h_startpos.lnum = current_lnum;
  			cur_si->si_h_startpos.col = 0;	// starts right away
  			cur_si->si_m_endpos.lnum = current_lnum;
  			cur_si->si_m_endpos.col = endcol;
  			cur_si->si_h_endpos.lnum = current_lnum;
  			cur_si->si_h_endpos.col = endcol;
  			cur_si->si_ends = TRUE;
  			cur_si->si_end_idx = 0;
  			cur_si->si_flags = flags;
  #ifdef FEAT_CONCEAL
  			cur_si->si_seqnr = next_seqnr++;
  			cur_si->si_cchar = cchar;
  			if (current_state.ga_len > 1)
  			    cur_si->si_flags |=
  				  CUR_STATE(current_state.ga_len - 2).si_flags
  								 & HL_CONCEAL;
  #endif
  			cur_si->si_id = syn_id;
  			cur_si->si_trans_id = syn_id;
  			if (flags & HL_TRANSP)
  			{
  			    if (current_state.ga_len < 2)
  			    {
  				cur_si->si_attr = 0;
  				cur_si->si_trans_id = 0;
  			    }
  			    else
  			    {
  				cur_si->si_attr = CUR_STATE(
  					current_state.ga_len - 2).si_attr;
  				cur_si->si_trans_id = CUR_STATE(
  					current_state.ga_len - 2).si_trans_id;
  			    }
  			}
  			else
  			    cur_si->si_attr = syn_id2attr(syn_id);
  			cur_si->si_cont_list = NULL;
  			cur_si->si_next_list = next_list;
  			check_keepend();
  		    }
  		    else
  			vim_free(next_list);
  		}
  	      }
  	    }
  
  	    /*
  	     * 3. Check for patterns (only if no keyword found).
  	     */
  	    if (syn_id == 0 && syn_block->b_syn_patterns.ga_len)
  	    {
  		/*
  		 * If we didn't check for a match yet, or we are past it, check
  		 * for any match with a pattern.
  		 */
  		if (next_match_idx < 0 || next_match_col < (int)current_col)
  		{
  		    /*
  		     * Check all relevant patterns for a match at this
  		     * position.  This is complicated, because matching with a
  		     * pattern takes quite a bit of time, thus we want to
  		     * avoid doing it when it's not needed.
  		     */
  		    next_match_idx = 0;		// no match in this line yet
  		    next_match_col = MAXCOL;
  		    for (idx = syn_block->b_syn_patterns.ga_len; --idx >= 0; )
  		    {
  			spp = &(SYN_ITEMS(syn_block)[idx]);
  			if (	   spp->sp_syncing == syncing
  				&& (displaying || !(spp->sp_flags & HL_DISPLAY))
  				&& (spp->sp_type == SPTYPE_MATCH
  				    || spp->sp_type == SPTYPE_START)
  				&& (current_next_list != NULL
  				    ? in_id_list(NULL, current_next_list,
  							      &spp->sp_syn, 0)
  				    : (cur_si == NULL
  					? !(spp->sp_flags & HL_CONTAINED)
  					: in_id_list(cur_si,
  					    cur_si->si_cont_list, &spp->sp_syn,
  					    spp->sp_flags & HL_CONTAINED))))
  			{
  			    int r;
  
  			    // If we already tried matching in this line, and
  			    // there isn't a match before next_match_col, skip
  			    // this item.
  			    if (spp->sp_line_id == current_line_id
  				    && spp->sp_startcol >= next_match_col)
  				continue;
  			    spp->sp_line_id = current_line_id;
  
  			    lc_col = current_col - spp->sp_offsets[SPO_LC_OFF];
  			    if (lc_col < 0)
  				lc_col = 0;
  
  			    regmatch.rmm_ic = spp->sp_ic;
  			    regmatch.regprog = spp->sp_prog;
  			    r = syn_regexec(&regmatch,
  					     current_lnum,
  					     (colnr_T)lc_col,
  					     IF_SYN_TIME(&spp->sp_time));
  			    spp->sp_prog = regmatch.regprog;
  			    if (!r)
  			    {
  				// no match in this line, try another one
  				spp->sp_startcol = MAXCOL;
  				continue;
  			    }
  
  			    /*
  			     * Compute the first column of the match.
  			     */
  			    syn_add_start_off(&pos, &regmatch,
  							 spp, SPO_MS_OFF, -1);
  			    if (pos.lnum > current_lnum)
  			    {
  				// must have used end of match in a next line,
  				// we can't handle that
  				spp->sp_startcol = MAXCOL;
  				continue;
  			    }
  			    startcol = pos.col;
  
  			    // remember the next column where this pattern
  			    // matches in the current line
  			    spp->sp_startcol = startcol;
  
  			    /*
  			     * If a previously found match starts at a lower
  			     * column number, don't use this one.
  			     */
  			    if (startcol >= next_match_col)
  				continue;
  
  			    /*
  			     * If we matched this pattern at this position
  			     * before, skip it.  Must retry in the next
  			     * column, because it may match from there.
  			     */
  			    if (did_match_already(idx, &zero_width_next_ga))
  			    {
  				try_next_column = TRUE;
  				continue;
  			    }
  
  			    endpos.lnum = regmatch.endpos[0].lnum;
  			    endpos.col = regmatch.endpos[0].col;
  
  			    // Compute the highlight start.
  			    syn_add_start_off(&hl_startpos, &regmatch,
  							 spp, SPO_HS_OFF, -1);
  
  			    // Compute the region start.
  			    // Default is to use the end of the match.
  			    syn_add_end_off(&eos_pos, &regmatch,
  							 spp, SPO_RS_OFF, 0);
  
  			    /*
  			     * Grab the external submatches before they get
  			     * overwritten.  Reference count doesn't change.
  			     */
  			    unref_extmatch(cur_extmatch);
  			    cur_extmatch = re_extmatch_out;
  			    re_extmatch_out = NULL;
  
  			    flags = 0;
  			    eoe_pos.lnum = 0;	// avoid warning
  			    eoe_pos.col = 0;
  			    end_idx = 0;
  			    hl_endpos.lnum = 0;
  
  			    /*
  			     * For a "oneline" the end must be found in the
  			     * same line too.  Search for it after the end of
  			     * the match with the start pattern.  Set the
  			     * resulting end positions at the same time.
  			     */
  			    if (spp->sp_type == SPTYPE_START
  					      && (spp->sp_flags & HL_ONELINE))
  			    {
  				lpos_T	startpos;
  
  				startpos = endpos;
  				find_endpos(idx, &startpos, &endpos, &hl_endpos,
  				    &flags, &eoe_pos, &end_idx, cur_extmatch);
  				if (endpos.lnum == 0)
  				    continue;	    // not found
  			    }
  
  			    /*
  			     * For a "match" the size must be > 0 after the
  			     * end offset needs has been added.  Except when
  			     * syncing.
  			     */
  			    else if (spp->sp_type == SPTYPE_MATCH)
  			    {
  				syn_add_end_off(&hl_endpos, &regmatch, spp,
  							       SPO_HE_OFF, 0);
  				syn_add_end_off(&endpos, &regmatch, spp,
  							       SPO_ME_OFF, 0);
  				if (endpos.lnum == current_lnum
  				      && (int)endpos.col + syncing < startcol)
  				{
  				    /*
  				     * If an empty string is matched, may need
  				     * to try matching again at next column.
  				     */
  				    if (regmatch.startpos[0].col
  						    == regmatch.endpos[0].col)
  					try_next_column = TRUE;
  				    continue;
  				}
  			    }
  
  			    /*
  			     * keep the best match so far in next_match_*
  			     */
  			    // Highlighting must start after startpos and end
  			    // before endpos.
  			    if (hl_startpos.lnum == current_lnum
  					   && (int)hl_startpos.col < startcol)
  				hl_startpos.col = startcol;
  			    limit_pos_zero(&hl_endpos, &endpos);
  
  			    next_match_idx = idx;
  			    next_match_col = startcol;
  			    next_match_m_endpos = endpos;
  			    next_match_h_endpos = hl_endpos;
  			    next_match_h_startpos = hl_startpos;
  			    next_match_flags = flags;
  			    next_match_eos_pos = eos_pos;
  			    next_match_eoe_pos = eoe_pos;
  			    next_match_end_idx = end_idx;
  			    unref_extmatch(next_match_extmatch);
  			    next_match_extmatch = cur_extmatch;
  			    cur_extmatch = NULL;
  			}
  		    }
  		}
  
  		/*
  		 * If we found a match at the current column, use it.
  		 */
  		if (next_match_idx >= 0 && next_match_col == (int)current_col)
  		{
  		    synpat_T	*lspp;
  
  		    // When a zero-width item matched which has a nextgroup,
  		    // don't push the item but set nextgroup.
  		    lspp = &(SYN_ITEMS(syn_block)[next_match_idx]);
  		    if (next_match_m_endpos.lnum == current_lnum
  			    && next_match_m_endpos.col == current_col
  			    && lspp->sp_next_list != NULL)
  		    {
  			current_next_list = lspp->sp_next_list;
  			current_next_flags = lspp->sp_flags;
  			keep_next_list = TRUE;
  			zero_width_next_list = TRUE;
  
  			// Add the index to a list, so that we can check
  			// later that we don't match it again (and cause an
  			// endless loop).
  			if (ga_grow(&zero_width_next_ga, 1) == OK)
  			{
  			    ((int *)(zero_width_next_ga.ga_data))
  				[zero_width_next_ga.ga_len++] = next_match_idx;
  			}
  			next_match_idx = -1;
  		    }
  		    else
  			cur_si = push_next_match(cur_si);
  		    found_match = TRUE;
  		}
  	    }
  	}
  
  	/*
  	 * Handle searching for nextgroup match.
  	 */
  	if (current_next_list != NULL && !keep_next_list)
  	{
  	    /*
  	     * If a nextgroup was not found, continue looking for one if:
  	     * - this is an empty line and the "skipempty" option was given
  	     * - we are on white space and the "skipwhite" option was given
  	     */
  	    if (!found_match)
  	    {
  		line = syn_getcurline();
  		if (((current_next_flags & HL_SKIPWHITE)
  			    && VIM_ISWHITE(line[current_col]))
  			|| ((current_next_flags & HL_SKIPEMPTY)
  			    && *line == NUL))
  		    break;
  	    }
  
  	    /*
  	     * If a nextgroup was found: Use it, and continue looking for
  	     * contained matches.
  	     * If a nextgroup was not found: Continue looking for a normal
  	     * match.
  	     * When did set current_next_list for a zero-width item and no
  	     * match was found don't loop (would get stuck).
  	     */
  	    current_next_list = NULL;
  	    next_match_idx = -1;
  	    if (!zero_width_next_list)
  		found_match = TRUE;
  	}
  
      } while (found_match);
  
      restore_chartab(buf_chartab);
  
      /*
       * Use attributes from the current state, if within its highlighting.
       * If not, use attributes from the current-but-one state, etc.
       */
      current_attr = 0;
  #ifdef FEAT_EVAL
      current_id = 0;
      current_trans_id = 0;
  #endif
  #ifdef FEAT_CONCEAL
      current_flags = 0;
      current_seqnr = 0;
  #endif
      if (cur_si != NULL)
      {
  #ifndef FEAT_EVAL
  	int	current_trans_id = 0;
  #endif
  	for (idx = current_state.ga_len - 1; idx >= 0; --idx)
  	{
  	    sip = &CUR_STATE(idx);
  	    if ((current_lnum > sip->si_h_startpos.lnum
  			|| (current_lnum == sip->si_h_startpos.lnum
  			    && current_col >= sip->si_h_startpos.col))
  		    && (sip->si_h_endpos.lnum == 0
  			|| current_lnum < sip->si_h_endpos.lnum
  			|| (current_lnum == sip->si_h_endpos.lnum
  			    && current_col < sip->si_h_endpos.col)))
  	    {
  		current_attr = sip->si_attr;
  #ifdef FEAT_EVAL
  		current_id = sip->si_id;
  #endif
  		current_trans_id = sip->si_trans_id;
  #ifdef FEAT_CONCEAL
  		current_flags = sip->si_flags;
  		current_seqnr = sip->si_seqnr;
  		current_sub_char = sip->si_cchar;
  #endif
  		break;
  	    }
  	}
  
  	if (can_spell != NULL)
  	{
  	    struct sp_syn   sps;
  
  	    /*
  	     * set "can_spell" to TRUE if spell checking is supposed to be
  	     * done in the current item.
  	     */
  	    if (syn_block->b_spell_cluster_id == 0)
  	    {
  		// There is no @Spell cluster: Do spelling for items without
  		// @NoSpell cluster.
  		if (syn_block->b_nospell_cluster_id == 0
  						     || current_trans_id == 0)
  		    *can_spell = (syn_block->b_syn_spell != SYNSPL_NOTOP);
  		else
  		{
  		    sps.inc_tag = 0;
  		    sps.id = syn_block->b_nospell_cluster_id;
  		    sps.cont_in_list = NULL;
  		    *can_spell = !in_id_list(sip, sip->si_cont_list, &sps, 0);
  		}
  	    }
  	    else
  	    {
  		// The @Spell cluster is defined: Do spelling in items with
  		// the @Spell cluster.  But not when @NoSpell is also there.
  		// At the toplevel only spell check when ":syn spell toplevel"
  		// was used.
  		if (current_trans_id == 0)
  		    *can_spell = (syn_block->b_syn_spell == SYNSPL_TOP);
  		else
  		{
  		    sps.inc_tag = 0;
  		    sps.id = syn_block->b_spell_cluster_id;
  		    sps.cont_in_list = NULL;
  		    *can_spell = in_id_list(sip, sip->si_cont_list, &sps, 0);
  
  		    if (syn_block->b_nospell_cluster_id != 0)
  		    {
  			sps.id = syn_block->b_nospell_cluster_id;
  			if (in_id_list(sip, sip->si_cont_list, &sps, 0))
  			    *can_spell = FALSE;
  		    }
  		}
  	    }
  	}
  
  
  	/*
  	 * Check for end of current state (and the states before it) at the
  	 * next column.  Don't do this for syncing, because we would miss a
  	 * single character match.
  	 * First check if the current state ends at the current column.  It
  	 * may be for an empty match and a containing item might end in the
  	 * current column.
  	 */
  	if (!syncing && !keep_state)
  	{
  	    check_state_ends();
  	    if (current_state.ga_len > 0
  				      && syn_getcurline()[current_col] != NUL)
  	    {
  		++current_col;
  		check_state_ends();
  		--current_col;
  	    }
  	}
      }
      else if (can_spell != NULL)
  	// Default: Only do spelling when there is no @Spell cluster or when
  	// ":syn spell toplevel" was used.
  	*can_spell = syn_block->b_syn_spell == SYNSPL_DEFAULT
  		    ? (syn_block->b_spell_cluster_id == 0)
  		    : (syn_block->b_syn_spell == SYNSPL_TOP);
  
      // nextgroup ends at end of line, unless "skipnl" or "skipempty" present
      if (current_next_list != NULL
  	    && (line = syn_getcurline())[current_col] != NUL
  	    && line[current_col + 1] == NUL
  	    && !(current_next_flags & (HL_SKIPNL | HL_SKIPEMPTY)))
  	current_next_list = NULL;
  
      if (zero_width_next_ga.ga_len > 0)
  	ga_clear(&zero_width_next_ga);
  
      // No longer need external matches.  But keep next_match_extmatch.
      unref_extmatch(re_extmatch_out);
      re_extmatch_out = NULL;
      unref_extmatch(cur_extmatch);
  
      return current_attr;
  }
  
  
  /*
   * Check if we already matched pattern "idx" at the current column.
   */
      static int
  did_match_already(int idx, garray_T *gap)
  {
      int		i;
  
      for (i = current_state.ga_len; --i >= 0; )
  	if (CUR_STATE(i).si_m_startcol == (int)current_col
  		&& CUR_STATE(i).si_m_lnum == (int)current_lnum
  		&& CUR_STATE(i).si_idx == idx)
  	    return TRUE;
  
      // Zero-width matches with a nextgroup argument are not put on the syntax
      // stack, and can only be matched once anyway.
      for (i = gap->ga_len; --i >= 0; )
  	if (((int *)(gap->ga_data))[i] == idx)
  	    return TRUE;
  
      return FALSE;
  }
  
  /*
   * Push the next match onto the stack.
   */
      static stateitem_T *
  push_next_match(stateitem_T *cur_si)
  {
      synpat_T	*spp;
  #ifdef FEAT_CONCEAL
      int		 save_flags;
  #endif
  
      spp = &(SYN_ITEMS(syn_block)[next_match_idx]);
  
      /*
       * Push the item in current_state stack;
       */
      if (push_current_state(next_match_idx) == OK)
      {
  	/*
  	 * If it's a start-skip-end type that crosses lines, figure out how
  	 * much it continues in this line.  Otherwise just fill in the length.
  	 */
  	cur_si = &CUR_STATE(current_state.ga_len - 1);
  	cur_si->si_h_startpos = next_match_h_startpos;
  	cur_si->si_m_startcol = current_col;
  	cur_si->si_m_lnum = current_lnum;
  	cur_si->si_flags = spp->sp_flags;
  #ifdef FEAT_CONCEAL
  	cur_si->si_seqnr = next_seqnr++;
  	cur_si->si_cchar = spp->sp_cchar;
  	if (current_state.ga_len > 1)
  	    cur_si->si_flags |=
  		    CUR_STATE(current_state.ga_len - 2).si_flags & HL_CONCEAL;
  #endif
  	cur_si->si_next_list = spp->sp_next_list;
  	cur_si->si_extmatch = ref_extmatch(next_match_extmatch);
  	if (spp->sp_type == SPTYPE_START && !(spp->sp_flags & HL_ONELINE))
  	{
  	    // Try to find the end pattern in the current line
  	    update_si_end(cur_si, (int)(next_match_m_endpos.col), TRUE);
  	    check_keepend();
  	}
  	else
  	{
  	    cur_si->si_m_endpos = next_match_m_endpos;
  	    cur_si->si_h_endpos = next_match_h_endpos;
  	    cur_si->si_ends = TRUE;
  	    cur_si->si_flags |= next_match_flags;
  	    cur_si->si_eoe_pos = next_match_eoe_pos;
  	    cur_si->si_end_idx = next_match_end_idx;
  	}
  	if (keepend_level < 0 && (cur_si->si_flags & HL_KEEPEND))
  	    keepend_level = current_state.ga_len - 1;
  	check_keepend();
  	update_si_attr(current_state.ga_len - 1);
  
  #ifdef FEAT_CONCEAL
  	save_flags = cur_si->si_flags & (HL_CONCEAL | HL_CONCEALENDS);
  #endif
  	/*
  	 * If the start pattern has another highlight group, push another item
  	 * on the stack for the start pattern.
  	 */
  	if (	   spp->sp_type == SPTYPE_START
  		&& spp->sp_syn_match_id != 0
  		&& push_current_state(next_match_idx) == OK)
  	{
  	    cur_si = &CUR_STATE(current_state.ga_len - 1);
  	    cur_si->si_h_startpos = next_match_h_startpos;
  	    cur_si->si_m_startcol = current_col;
  	    cur_si->si_m_lnum = current_lnum;
  	    cur_si->si_m_endpos = next_match_eos_pos;
  	    cur_si->si_h_endpos = next_match_eos_pos;
  	    cur_si->si_ends = TRUE;
  	    cur_si->si_end_idx = 0;
  	    cur_si->si_flags = HL_MATCH;
  #ifdef FEAT_CONCEAL
  	    cur_si->si_seqnr = next_seqnr++;
  	    cur_si->si_flags |= save_flags;
  	    if (cur_si->si_flags & HL_CONCEALENDS)
  		cur_si->si_flags |= HL_CONCEAL;
  #endif
  	    cur_si->si_next_list = NULL;
  	    check_keepend();
  	    update_si_attr(current_state.ga_len - 1);
  	}
      }
  
      next_match_idx = -1;	// try other match next time
  
      return cur_si;
  }
  
  /*
   * Check for end of current state (and the states before it).
   */
      static void
  check_state_ends(void)
  {
      stateitem_T	*cur_si;
      int		had_extend;
  
      cur_si = &CUR_STATE(current_state.ga_len - 1);
      for (;;)
      {
  	if (cur_si->si_ends
  		&& (cur_si->si_m_endpos.lnum < current_lnum
  		    || (cur_si->si_m_endpos.lnum == current_lnum
  			&& cur_si->si_m_endpos.col <= current_col)))
  	{
  	    /*
  	     * If there is an end pattern group ID, highlight the end pattern
  	     * now.  No need to pop the current item from the stack.
  	     * Only do this if the end pattern continues beyond the current
  	     * position.
  	     */
  	    if (cur_si->si_end_idx
  		    && (cur_si->si_eoe_pos.lnum > current_lnum
  			|| (cur_si->si_eoe_pos.lnum == current_lnum
  			    && cur_si->si_eoe_pos.col > current_col)))
  	    {
  		cur_si->si_idx = cur_si->si_end_idx;
  		cur_si->si_end_idx = 0;
  		cur_si->si_m_endpos = cur_si->si_eoe_pos;
  		cur_si->si_h_endpos = cur_si->si_eoe_pos;
  		cur_si->si_flags |= HL_MATCH;
  #ifdef FEAT_CONCEAL
  		cur_si->si_seqnr = next_seqnr++;
  		if (cur_si->si_flags & HL_CONCEALENDS)
  		    cur_si->si_flags |= HL_CONCEAL;
  #endif
  		update_si_attr(current_state.ga_len - 1);
  
  		// nextgroup= should not match in the end pattern
  		current_next_list = NULL;
  
  		// what matches next may be different now, clear it
  		next_match_idx = 0;
  		next_match_col = MAXCOL;
  		break;
  	    }
  	    else
  	    {
  		// handle next_list, unless at end of line and no "skipnl" or
  		// "skipempty"
  		current_next_list = cur_si->si_next_list;
  		current_next_flags = cur_si->si_flags;
  		if (!(current_next_flags & (HL_SKIPNL | HL_SKIPEMPTY))
  			&& syn_getcurline()[current_col] == NUL)
  		    current_next_list = NULL;
  
  		// When the ended item has "extend", another item with
  		// "keepend" now needs to check for its end.
  		 had_extend = (cur_si->si_flags & HL_EXTEND);
  
  		pop_current_state();
  
  		if (current_state.ga_len == 0)
  		    break;
  
  		if (had_extend && keepend_level >= 0)
  		{
  		    syn_update_ends(FALSE);
  		    if (current_state.ga_len == 0)
  			break;
  		}
  
  		cur_si = &CUR_STATE(current_state.ga_len - 1);
  
  		/*
  		 * Only for a region the search for the end continues after
  		 * the end of the contained item.  If the contained match
  		 * included the end-of-line, break here, the region continues.
  		 * Don't do this when:
  		 * - "keepend" is used for the contained item
  		 * - not at the end of the line (could be end="x$"me=e-1).
  		 * - "excludenl" is used (HL_HAS_EOL won't be set)
  		 */
  		if (cur_si->si_idx >= 0
  			&& SYN_ITEMS(syn_block)[cur_si->si_idx].sp_type
  							       == SPTYPE_START
  			&& !(cur_si->si_flags & (HL_MATCH | HL_KEEPEND)))
  		{
  		    update_si_end(cur_si, (int)current_col, TRUE);
  		    check_keepend();
  		    if ((current_next_flags & HL_HAS_EOL)
  			    && keepend_level < 0
  			    && syn_getcurline()[current_col] == NUL)
  			break;
  		}
  	    }
  	}
  	else
  	    break;
      }
  }
  
  /*
   * Update an entry in the current_state stack for a match or region.  This
   * fills in si_attr, si_next_list and si_cont_list.
   */
      static void
  update_si_attr(int idx)
  {
      stateitem_T	*sip = &CUR_STATE(idx);
      synpat_T	*spp;
  
      // This should not happen...
      if (sip->si_idx < 0)
  	return;
  
      spp = &(SYN_ITEMS(syn_block)[sip->si_idx]);
      if (sip->si_flags & HL_MATCH)
  	sip->si_id = spp->sp_syn_match_id;
      else
  	sip->si_id = spp->sp_syn.id;
      sip->si_attr = syn_id2attr(sip->si_id);
      sip->si_trans_id = sip->si_id;
      if (sip->si_flags & HL_MATCH)
  	sip->si_cont_list = NULL;
      else
  	sip->si_cont_list = spp->sp_cont_list;
  
      /*
       * For transparent items, take attr from outer item.
       * Also take cont_list, if there is none.
       * Don't do this for the matchgroup of a start or end pattern.
       */
      if ((spp->sp_flags & HL_TRANSP) && !(sip->si_flags & HL_MATCH))
      {
  	if (idx == 0)
  	{
  	    sip->si_attr = 0;
  	    sip->si_trans_id = 0;
  	    if (sip->si_cont_list == NULL)
  		sip->si_cont_list = ID_LIST_ALL;
  	}
  	else
  	{
  	    sip->si_attr = CUR_STATE(idx - 1).si_attr;
  	    sip->si_trans_id = CUR_STATE(idx - 1).si_trans_id;
  	    sip->si_h_startpos = CUR_STATE(idx - 1).si_h_startpos;
  	    sip->si_h_endpos = CUR_STATE(idx - 1).si_h_endpos;
  	    if (sip->si_cont_list == NULL)
  	    {
  		sip->si_flags |= HL_TRANS_CONT;
  		sip->si_cont_list = CUR_STATE(idx - 1).si_cont_list;
  	    }
  	}
      }
  }
  
  /*
   * Check the current stack for patterns with "keepend" flag.
   * Propagate the match-end to contained items, until a "skipend" item is found.
   */
      static void
  check_keepend(void)
  {
      int		i;
      lpos_T	maxpos;
      lpos_T	maxpos_h;
      stateitem_T	*sip;
  
      /*
       * This check can consume a lot of time; only do it from the level where
       * there really is a keepend.
       */
      if (keepend_level < 0)
  	return;
  
      /*
       * Find the last index of an "extend" item.  "keepend" items before that
       * won't do anything.  If there is no "extend" item "i" will be
       * "keepend_level" and all "keepend" items will work normally.
       */
      for (i = current_state.ga_len - 1; i > keepend_level; --i)
  	if (CUR_STATE(i).si_flags & HL_EXTEND)
  	    break;
  
      maxpos.lnum = 0;
      maxpos.col = 0;
      maxpos_h.lnum = 0;
      maxpos_h.col = 0;
      for ( ; i < current_state.ga_len; ++i)
      {
  	sip = &CUR_STATE(i);
  	if (maxpos.lnum != 0)
  	{
  	    limit_pos_zero(&sip->si_m_endpos, &maxpos);
  	    limit_pos_zero(&sip->si_h_endpos, &maxpos_h);
  	    limit_pos_zero(&sip->si_eoe_pos, &maxpos);
  	    sip->si_ends = TRUE;
  	}
  	if (sip->si_ends && (sip->si_flags & HL_KEEPEND))
  	{
  	    if (maxpos.lnum == 0
  		    || maxpos.lnum > sip->si_m_endpos.lnum
  		    || (maxpos.lnum == sip->si_m_endpos.lnum
  			&& maxpos.col > sip->si_m_endpos.col))
  		maxpos = sip->si_m_endpos;
  	    if (maxpos_h.lnum == 0
  		    || maxpos_h.lnum > sip->si_h_endpos.lnum
  		    || (maxpos_h.lnum == sip->si_h_endpos.lnum
  			&& maxpos_h.col > sip->si_h_endpos.col))
  		maxpos_h = sip->si_h_endpos;
  	}
      }
  }
  
  /*
   * Update an entry in the current_state stack for a start-skip-end pattern.
   * This finds the end of the current item, if it's in the current line.
   *
   * Return the flags for the matched END.
   */
      static void
  update_si_end(
      stateitem_T	*sip,
      int		startcol,   // where to start searching for the end
      int		force)	    // when TRUE overrule a previous end
  {
      lpos_T	startpos;
      lpos_T	endpos;
      lpos_T	hl_endpos;
      lpos_T	end_endpos;
      int		end_idx;
  
      // return quickly for a keyword
      if (sip->si_idx < 0)
  	return;
  
      // Don't update when it's already done.  Can be a match of an end pattern
      // that started in a previous line.  Watch out: can also be a "keepend"
      // from a containing item.
      if (!force && sip->si_m_endpos.lnum >= current_lnum)
  	return;
  
      /*
       * We need to find the end of the region.  It may continue in the next
       * line.
       */
      end_idx = 0;
      startpos.lnum = current_lnum;
      startpos.col = startcol;
      find_endpos(sip->si_idx, &startpos, &endpos, &hl_endpos,
  		   &(sip->si_flags), &end_endpos, &end_idx, sip->si_extmatch);
  
      if (endpos.lnum == 0)
      {
  	// No end pattern matched.
  	if (SYN_ITEMS(syn_block)[sip->si_idx].sp_flags & HL_ONELINE)
  	{
  	    // a "oneline" never continues in the next line
  	    sip->si_ends = TRUE;
  	    sip->si_m_endpos.lnum = current_lnum;
  	    sip->si_m_endpos.col = (colnr_T)STRLEN(syn_getcurline());
  	}
  	else
  	{
  	    // continues in the next line
  	    sip->si_ends = FALSE;
  	    sip->si_m_endpos.lnum = 0;
  	}
  	sip->si_h_endpos = sip->si_m_endpos;
      }
      else
      {
  	// match within this line
  	sip->si_m_endpos = endpos;
  	sip->si_h_endpos = hl_endpos;
  	sip->si_eoe_pos = end_endpos;
  	sip->si_ends = TRUE;
  	sip->si_end_idx = end_idx;
      }
  }
  
  /*
   * Add a new state to the current state stack.
   * It is cleared and the index set to "idx".
   * Return FAIL if it's not possible (out of memory).
   */
      static int
  push_current_state(int idx)
  {
      if (ga_grow(&current_state, 1) == FAIL)
  	return FAIL;
      CLEAR_POINTER(&CUR_STATE(current_state.ga_len));
      CUR_STATE(current_state.ga_len).si_idx = idx;
      ++current_state.ga_len;
      return OK;
  }
  
  /*
   * Remove a state from the current_state stack.
   */
      static void
  pop_current_state(void)
  {
      if (current_state.ga_len)
      {
  	unref_extmatch(CUR_STATE(current_state.ga_len - 1).si_extmatch);
  	--current_state.ga_len;
      }
      // after the end of a pattern, try matching a keyword or pattern
      next_match_idx = -1;
  
      // if first state with "keepend" is popped, reset keepend_level
      if (keepend_level >= current_state.ga_len)
  	keepend_level = -1;
  }
  
  /*
   * Find the end of a start/skip/end syntax region after "startpos".
   * Only checks one line.
   * Also handles a match item that continued from a previous line.
   * If not found, the syntax item continues in the next line.  m_endpos->lnum
   * will be 0.
   * If found, the end of the region and the end of the highlighting is
   * computed.
   */
      static void
  find_endpos(
      int		idx,		// index of the pattern
      lpos_T	*startpos,	// where to start looking for an END match
      lpos_T	*m_endpos,	// return: end of match
      lpos_T	*hl_endpos,	// return: end of highlighting
      long	*flagsp,	// return: flags of matching END
      lpos_T	*end_endpos,	// return: end of end pattern match
      int		*end_idx,	// return: group ID for end pat. match, or 0
      reg_extmatch_T *start_ext)	// submatches from the start pattern
  {
      colnr_T	matchcol;
      synpat_T	*spp, *spp_skip;
      int		start_idx;
      int		best_idx;
      regmmatch_T	regmatch;
      regmmatch_T	best_regmatch;	    // startpos/endpos of best match
      lpos_T	pos;
      char_u	*line;
      int		had_match = FALSE;
      char_u	buf_chartab[32];  // chartab array for syn option iskyeyword
  
      // just in case we are invoked for a keyword
      if (idx < 0)
  	return;
  
      /*
       * Check for being called with a START pattern.
       * Can happen with a match that continues to the next line, because it
       * contained a region.
       */
      spp = &(SYN_ITEMS(syn_block)[idx]);
      if (spp->sp_type != SPTYPE_START)
      {
  	*hl_endpos = *startpos;
  	return;
      }
  
      /*
       * Find the SKIP or first END pattern after the last START pattern.
       */
      for (;;)
      {
  	spp = &(SYN_ITEMS(syn_block)[idx]);
  	if (spp->sp_type != SPTYPE_START)
  	    break;
  	++idx;
      }
  
      /*
       *	Lookup the SKIP pattern (if present)
       */
      if (spp->sp_type == SPTYPE_SKIP)
      {
  	spp_skip = spp;
  	++idx;
      }
      else
  	spp_skip = NULL;
  
      // Setup external matches for syn_regexec().
      unref_extmatch(re_extmatch_in);
      re_extmatch_in = ref_extmatch(start_ext);
  
      matchcol = startpos->col;	// start looking for a match at sstart
      start_idx = idx;		// remember the first END pattern.
      best_regmatch.startpos[0].col = 0;		// avoid compiler warning
  
      // use syntax iskeyword option
      save_chartab(buf_chartab);
  
      for (;;)
      {
  	/*
  	 * Find end pattern that matches first after "matchcol".
  	 */
  	best_idx = -1;
  	for (idx = start_idx; idx < syn_block->b_syn_patterns.ga_len; ++idx)
  	{
  	    int lc_col = matchcol;
  	    int r;
  
  	    spp = &(SYN_ITEMS(syn_block)[idx]);
  	    if (spp->sp_type != SPTYPE_END)	// past last END pattern
  		break;
  	    lc_col -= spp->sp_offsets[SPO_LC_OFF];
  	    if (lc_col < 0)
  		lc_col = 0;
  
  	    regmatch.rmm_ic = spp->sp_ic;
  	    regmatch.regprog = spp->sp_prog;
  	    r = syn_regexec(&regmatch, startpos->lnum, lc_col,
  						  IF_SYN_TIME(&spp->sp_time));
  	    spp->sp_prog = regmatch.regprog;
  	    if (r)
  	    {
  		if (best_idx == -1 || regmatch.startpos[0].col
  					      < best_regmatch.startpos[0].col)
  		{
  		    best_idx = idx;
  		    best_regmatch.startpos[0] = regmatch.startpos[0];
  		    best_regmatch.endpos[0] = regmatch.endpos[0];
  		}
  	    }
  	}
  
  	/*
  	 * If all end patterns have been tried, and there is no match, the
  	 * item continues until end-of-line.
  	 */
  	if (best_idx == -1)
  	    break;
  
  	/*
  	 * If the skip pattern matches before the end pattern,
  	 * continue searching after the skip pattern.
  	 */
  	if (spp_skip != NULL)
  	{
  	    int lc_col = matchcol - spp_skip->sp_offsets[SPO_LC_OFF];
  	    int r;
  
  	    if (lc_col < 0)
  		lc_col = 0;
  	    regmatch.rmm_ic = spp_skip->sp_ic;
  	    regmatch.regprog = spp_skip->sp_prog;
  	    r = syn_regexec(&regmatch, startpos->lnum, lc_col,
  					      IF_SYN_TIME(&spp_skip->sp_time));
  	    spp_skip->sp_prog = regmatch.regprog;
  	    if (r && regmatch.startpos[0].col
  					     <= best_regmatch.startpos[0].col)
  	    {
  		int line_len;
  
  		// Add offset to skip pattern match
  		syn_add_end_off(&pos, &regmatch, spp_skip, SPO_ME_OFF, 1);
  
  		// If the skip pattern goes on to the next line, there is no
  		// match with an end pattern in this line.
  		if (pos.lnum > startpos->lnum)
  		    break;
  
  		line = ml_get_buf(syn_buf, startpos->lnum, FALSE);
  		line_len = (int)STRLEN(line);
  
  		// take care of an empty match or negative offset
  		if (pos.col <= matchcol)
  		    ++matchcol;
  		else if (pos.col <= regmatch.endpos[0].col)
  		    matchcol = pos.col;
  		else
  		    // Be careful not to jump over the NUL at the end-of-line
  		    for (matchcol = regmatch.endpos[0].col;
  			    matchcol < line_len && matchcol < pos.col;
  								   ++matchcol)
  			;
  
  		// if the skip pattern includes end-of-line, break here
  		if (matchcol >= line_len)
  		    break;
  
  		continue;	    // start with first end pattern again
  	    }
  	}
  
  	/*
  	 * Match from start pattern to end pattern.
  	 * Correct for match and highlight offset of end pattern.
  	 */
  	spp = &(SYN_ITEMS(syn_block)[best_idx]);
  	syn_add_end_off(m_endpos, &best_regmatch, spp, SPO_ME_OFF, 1);
  	// can't end before the start
  	if (m_endpos->lnum == startpos->lnum && m_endpos->col < startpos->col)
  	    m_endpos->col = startpos->col;
  
  	syn_add_end_off(end_endpos, &best_regmatch, spp, SPO_HE_OFF, 1);
  	// can't end before the start
  	if (end_endpos->lnum == startpos->lnum
  					   && end_endpos->col < startpos->col)
  	    end_endpos->col = startpos->col;
  	// can't end after the match
  	limit_pos(end_endpos, m_endpos);
  
  	/*
  	 * If the end group is highlighted differently, adjust the pointers.
  	 */
  	if (spp->sp_syn_match_id != spp->sp_syn.id && spp->sp_syn_match_id != 0)
  	{
  	    *end_idx = best_idx;
  	    if (spp->sp_off_flags & (1 << (SPO_RE_OFF + SPO_COUNT)))
  	    {
  		hl_endpos->lnum = best_regmatch.endpos[0].lnum;
  		hl_endpos->col = best_regmatch.endpos[0].col;
  	    }
  	    else
  	    {
  		hl_endpos->lnum = best_regmatch.startpos[0].lnum;
  		hl_endpos->col = best_regmatch.startpos[0].col;
  	    }
  	    hl_endpos->col += spp->sp_offsets[SPO_RE_OFF];
  
  	    // can't end before the start
  	    if (hl_endpos->lnum == startpos->lnum
  					    && hl_endpos->col < startpos->col)
  		hl_endpos->col = startpos->col;
  	    limit_pos(hl_endpos, m_endpos);
  
  	    // now the match ends where the highlighting ends, it is turned
  	    // into the matchgroup for the end
  	    *m_endpos = *hl_endpos;
  	}
  	else
  	{
  	    *end_idx = 0;
  	    *hl_endpos = *end_endpos;
  	}
  
  	*flagsp = spp->sp_flags;
  
  	had_match = TRUE;
  	break;
      }
  
      // no match for an END pattern in this line
      if (!had_match)
  	m_endpos->lnum = 0;
  
      restore_chartab(buf_chartab);
  
      // Remove external matches.
      unref_extmatch(re_extmatch_in);
      re_extmatch_in = NULL;
  }
  
  /*
   * Limit "pos" not to be after "limit".
   */
      static void
  limit_pos(lpos_T *pos, lpos_T *limit)
  {
      if (pos->lnum > limit->lnum)
  	*pos = *limit;
      else if (pos->lnum == limit->lnum && pos->col > limit->col)
  	pos->col = limit->col;
  }
  
  /*
   * Limit "pos" not to be after "limit", unless pos->lnum is zero.
   */
      static void
  limit_pos_zero(
      lpos_T	*pos,
      lpos_T	*limit)
  {
      if (pos->lnum == 0)
  	*pos = *limit;
      else
  	limit_pos(pos, limit);
  }
  
  /*
   * Add offset to matched text for end of match or highlight.
   */
      static void
  syn_add_end_off(
      lpos_T	*result,	// returned position
      regmmatch_T	*regmatch,	// start/end of match
      synpat_T	*spp,		// matched pattern
      int		idx,		// index of offset
      int		extra)		// extra chars for offset to start
  {
      int		col;
      int		off;
      char_u	*base;
      char_u	*p;
  
      if (spp->sp_off_flags & (1 << idx))
      {
  	result->lnum = regmatch->startpos[0].lnum;
  	col = regmatch->startpos[0].col;
  	off = spp->sp_offsets[idx] + extra;
      }
      else
      {
  	result->lnum = regmatch->endpos[0].lnum;
  	col = regmatch->endpos[0].col;
  	off = spp->sp_offsets[idx];
      }
      // Don't go past the end of the line.  Matters for "rs=e+2" when there
      // is a matchgroup. Watch out for match with last NL in the buffer.
      if (result->lnum > syn_buf->b_ml.ml_line_count)
  	col = 0;
      else if (off != 0)
      {
  	base = ml_get_buf(syn_buf, result->lnum, FALSE);
  	p = base + col;
  	if (off > 0)
  	{
  	    while (off-- > 0 && *p != NUL)
  		MB_PTR_ADV(p);
  	}
  	else if (off < 0)
  	{
  	    while (off++ < 0 && base < p)
  		MB_PTR_BACK(base, p);
  	}
  	col = (int)(p - base);
      }
      result->col = col;
  }
  
  /*
   * Add offset to matched text for start of match or highlight.
   * Avoid resulting column to become negative.
   */
      static void
  syn_add_start_off(
      lpos_T	*result,	// returned position
      regmmatch_T	*regmatch,	// start/end of match
      synpat_T	*spp,
      int		idx,
      int		extra)	    // extra chars for offset to end
  {
      int		col;
      int		off;
      char_u	*base;
      char_u	*p;
  
      if (spp->sp_off_flags & (1 << (idx + SPO_COUNT)))
      {
  	result->lnum = regmatch->endpos[0].lnum;
  	col = regmatch->endpos[0].col;
  	off = spp->sp_offsets[idx] + extra;
      }
      else
      {
  	result->lnum = regmatch->startpos[0].lnum;
  	col = regmatch->startpos[0].col;
  	off = spp->sp_offsets[idx];
      }
      if (result->lnum > syn_buf->b_ml.ml_line_count)
      {
  	// a "\n" at the end of the pattern may take us below the last line
  	result->lnum = syn_buf->b_ml.ml_line_count;
  	col = (int)STRLEN(ml_get_buf(syn_buf, result->lnum, FALSE));
      }
      if (off != 0)
      {
  	base = ml_get_buf(syn_buf, result->lnum, FALSE);
  	p = base + col;
  	if (off > 0)
  	{
  	    while (off-- && *p != NUL)
  		MB_PTR_ADV(p);
  	}
  	else if (off < 0)
  	{
  	    while (off++ && base < p)
  		MB_PTR_BACK(base, p);
  	}
  	col = (int)(p - base);
      }
      result->col = col;
  }
  
  /*
   * Get current line in syntax buffer.
   */
      static char_u *
  syn_getcurline(void)
  {
      return ml_get_buf(syn_buf, current_lnum, FALSE);
  }
  
  /*
   * Call vim_regexec() to find a match with "rmp" in "syn_buf".
   * Returns TRUE when there is a match.
   */
      static int
  syn_regexec(
      regmmatch_T	*rmp,
      linenr_T	lnum,
      colnr_T	col,
      syn_time_T  *st UNUSED)
  {
      int r;
  #ifdef FEAT_RELTIME
      int timed_out = FALSE;
  #endif
  #ifdef FEAT_PROFILE
      proftime_T	pt;
  
      if (syn_time_on)
  	profile_start(&pt);
  #endif
  
      if (rmp->regprog == NULL)
  	// This can happen if a previous call to vim_regexec_multi() tried to
  	// use the NFA engine, which resulted in NFA_TOO_EXPENSIVE, and
  	// compiling the pattern with the other engine fails.
  	return FALSE;
  
      rmp->rmm_maxcol = syn_buf->b_p_smc;
      r = vim_regexec_multi(rmp, syn_win, syn_buf, lnum, col,
  #ifdef FEAT_RELTIME
  	    syn_tm, &timed_out
  #else
  	    NULL, NULL
  #endif
  	    );
  
  #ifdef FEAT_PROFILE
      if (syn_time_on)
      {
  	profile_end(&pt);
  	profile_add(&st->total, &pt);
  	if (profile_cmp(&pt, &st->slowest) < 0)
  	    st->slowest = pt;
  	++st->count;
  	if (r > 0)
  	    ++st->match;
      }
  #endif
  #ifdef FEAT_RELTIME
      if (timed_out && !syn_win->w_s->b_syn_slow)
      {
  	syn_win->w_s->b_syn_slow = TRUE;
  	msg(_("'redrawtime' exceeded, syntax highlighting disabled"));
      }
  #endif
  
      if (r > 0)
      {
  	rmp->startpos[0].lnum += lnum;
  	rmp->endpos[0].lnum += lnum;
  	return TRUE;
      }
      return FALSE;
  }
  
  /*
   * Check one position in a line for a matching keyword.
   * The caller must check if a keyword can start at startcol.
   * Return its ID if found, 0 otherwise.
   */
      static int
  check_keyword_id(
      char_u	*line,
      int		startcol,	// position in line to check for keyword
      int		*endcolp,	// return: character after found keyword
      long	*flagsp,	// return: flags of matching keyword
      short	**next_listp,	// return: next_list of matching keyword
      stateitem_T	*cur_si,	// item at the top of the stack
      int		*ccharp UNUSED)	// conceal substitution char
  {
      keyentry_T	*kp;
      char_u	*kwp;
      int		round;
      int		kwlen;
      char_u	keyword[MAXKEYWLEN + 1]; // assume max. keyword len is 80
      hashtab_T	*ht;
      hashitem_T	*hi;
  
      // Find first character after the keyword.  First character was already
      // checked.
      kwp = line + startcol;
      kwlen = 0;
      do
      {
  	if (has_mbyte)
  	    kwlen += (*mb_ptr2len)(kwp + kwlen);
  	else
  	    ++kwlen;
      }
      while (vim_iswordp_buf(kwp + kwlen, syn_buf));
  
      if (kwlen > MAXKEYWLEN)
  	return 0;
  
      /*
       * Must make a copy of the keyword, so we can add a NUL and make it
       * lowercase.
       */
      vim_strncpy(keyword, kwp, kwlen);
  
      /*
       * Try twice:
       * 1. matching case
       * 2. ignoring case
       */
      for (round = 1; round <= 2; ++round)
      {
  	ht = round == 1 ? &syn_block->b_keywtab : &syn_block->b_keywtab_ic;
  	if (ht->ht_used == 0)
  	    continue;
  	if (round == 2)	// ignore case
  	    (void)str_foldcase(kwp, kwlen, keyword, MAXKEYWLEN + 1);
  
  	/*
  	 * Find keywords that match.  There can be several with different
  	 * attributes.
  	 * When current_next_list is non-zero accept only that group, otherwise:
  	 *  Accept a not-contained keyword at toplevel.
  	 *  Accept a keyword at other levels only if it is in the contains list.
  	 */
  	hi = hash_find(ht, keyword);
  	if (!HASHITEM_EMPTY(hi))
  	    for (kp = HI2KE(hi); kp != NULL; kp = kp->ke_next)
  	    {
  		if (current_next_list != 0
  			? in_id_list(NULL, current_next_list, &kp->k_syn, 0)
  			: (cur_si == NULL
  			    ? !(kp->flags & HL_CONTAINED)
  			    : in_id_list(cur_si, cur_si->si_cont_list,
  				      &kp->k_syn, kp->flags & HL_CONTAINED)))
  		{
  		    *endcolp = startcol + kwlen;
  		    *flagsp = kp->flags;
  		    *next_listp = kp->next_list;
  #ifdef FEAT_CONCEAL
  		    *ccharp = kp->k_char;
  #endif
  		    return kp->k_syn.id;
  		}
  	    }
      }
      return 0;
  }
  
  /*
   * Handle ":syntax conceal" command.
   */
      static void
  syn_cmd_conceal(exarg_T *eap UNUSED, int syncing UNUSED)
  {
  #ifdef FEAT_CONCEAL
      char_u	*arg = eap->arg;
      char_u	*next;
  
      eap->nextcmd = find_nextcmd(arg);
      if (eap->skip)
  	return;
  
      next = skiptowhite(arg);
      if (*arg == NUL)
      {
  	if (curwin->w_s->b_syn_conceal)
  	    msg(_("syntax conceal on"));
  	else
  	    msg(_("syntax conceal off"));
      }
      else if (STRNICMP(arg, "on", 2) == 0 && next - arg == 2)
  	curwin->w_s->b_syn_conceal = TRUE;
      else if (STRNICMP(arg, "off", 3) == 0 && next - arg == 3)
  	curwin->w_s->b_syn_conceal = FALSE;
      else
  	semsg(_("E390: Illegal argument: %s"), arg);
  #endif
  }
  
  /*
   * Handle ":syntax case" command.
   */
      static void
  syn_cmd_case(exarg_T *eap, int syncing UNUSED)
  {
      char_u	*arg = eap->arg;
      char_u	*next;
  
      eap->nextcmd = find_nextcmd(arg);
      if (eap->skip)
  	return;
  
      next = skiptowhite(arg);
      if (*arg == NUL)
      {
  	if (curwin->w_s->b_syn_ic)
  	    msg(_("syntax case ignore"));
  	else
  	    msg(_("syntax case match"));
      }
      else if (STRNICMP(arg, "match", 5) == 0 && next - arg == 5)
  	curwin->w_s->b_syn_ic = FALSE;
      else if (STRNICMP(arg, "ignore", 6) == 0 && next - arg == 6)
  	curwin->w_s->b_syn_ic = TRUE;
      else
  	semsg(_("E390: Illegal argument: %s"), arg);
  }
  
  /*
   * Handle ":syntax spell" command.
   */
      static void
  syn_cmd_spell(exarg_T *eap, int syncing UNUSED)
  {
      char_u	*arg = eap->arg;
      char_u	*next;
  
      eap->nextcmd = find_nextcmd(arg);
      if (eap->skip)
  	return;
  
      next = skiptowhite(arg);
      if (*arg == NUL)
      {
  	if (curwin->w_s->b_syn_spell == SYNSPL_TOP)
  	    msg(_("syntax spell toplevel"));
  	else if (curwin->w_s->b_syn_spell == SYNSPL_NOTOP)
  	    msg(_("syntax spell notoplevel"));
  	else
  	    msg(_("syntax spell default"));
      }
      else if (STRNICMP(arg, "toplevel", 8) == 0 && next - arg == 8)
  	curwin->w_s->b_syn_spell = SYNSPL_TOP;
      else if (STRNICMP(arg, "notoplevel", 10) == 0 && next - arg == 10)
  	curwin->w_s->b_syn_spell = SYNSPL_NOTOP;
      else if (STRNICMP(arg, "default", 7) == 0 && next - arg == 7)
  	curwin->w_s->b_syn_spell = SYNSPL_DEFAULT;
      else
      {
  	semsg(_("E390: Illegal argument: %s"), arg);
  	return;
      }
  
      // assume spell checking changed, force a redraw
      redraw_win_later(curwin, NOT_VALID);
  }
  
  /*
   * Handle ":syntax iskeyword" command.
   */
      static void
  syn_cmd_iskeyword(exarg_T *eap, int syncing UNUSED)
  {
      char_u	*arg = eap->arg;
      char_u	save_chartab[32];
      char_u	*save_isk;
  
      if (eap->skip)
  	return;
  
      arg = skipwhite(arg);
      if (*arg == NUL)
      {
  	msg_puts("\n");
  	if (curwin->w_s->b_syn_isk != empty_option)
  	{
  	    msg_puts(_("syntax iskeyword "));
  	    msg_outtrans(curwin->w_s->b_syn_isk);
  	}
  	else
  	    msg_outtrans((char_u *)_("syntax iskeyword not set"));
      }
      else
      {
  	if (STRNICMP(arg, "clear", 5) == 0)
  	{
  	    mch_memmove(curwin->w_s->b_syn_chartab, curbuf->b_chartab,
  								  (size_t)32);
  	    clear_string_option(&curwin->w_s->b_syn_isk);
  	}
  	else
  	{
  	    mch_memmove(save_chartab, curbuf->b_chartab, (size_t)32);
  	    save_isk = curbuf->b_p_isk;
  	    curbuf->b_p_isk = vim_strsave(arg);
  
  	    buf_init_chartab(curbuf, FALSE);
  	    mch_memmove(curwin->w_s->b_syn_chartab, curbuf->b_chartab,
  								  (size_t)32);
  	    mch_memmove(curbuf->b_chartab, save_chartab, (size_t)32);
  	    clear_string_option(&curwin->w_s->b_syn_isk);
  	    curwin->w_s->b_syn_isk = curbuf->b_p_isk;
  	    curbuf->b_p_isk = save_isk;
  	}
      }
      redraw_win_later(curwin, NOT_VALID);
  }
  
  /*
   * Clear all syntax info for one buffer.
   */
      void
  syntax_clear(synblock_T *block)
  {
      int i;
  
      block->b_syn_error = FALSE;	    // clear previous error
  #ifdef FEAT_RELTIME
      block->b_syn_slow = FALSE;	    // clear previous timeout
  #endif
      block->b_syn_ic = FALSE;	    // Use case, by default
      block->b_syn_spell = SYNSPL_DEFAULT; // default spell checking
      block->b_syn_containedin = FALSE;
  #ifdef FEAT_CONCEAL
      block->b_syn_conceal = FALSE;
  #endif
  
      // free the keywords
      clear_keywtab(&block->b_keywtab);
      clear_keywtab(&block->b_keywtab_ic);
  
      // free the syntax patterns
      for (i = block->b_syn_patterns.ga_len; --i >= 0; )
  	syn_clear_pattern(block, i);
      ga_clear(&block->b_syn_patterns);
  
      // free the syntax clusters
      for (i = block->b_syn_clusters.ga_len; --i >= 0; )
  	syn_clear_cluster(block, i);
      ga_clear(&block->b_syn_clusters);
      block->b_spell_cluster_id = 0;
      block->b_nospell_cluster_id = 0;
  
      block->b_syn_sync_flags = 0;
      block->b_syn_sync_minlines = 0;
      block->b_syn_sync_maxlines = 0;
      block->b_syn_sync_linebreaks = 0;
  
      vim_regfree(block->b_syn_linecont_prog);
      block->b_syn_linecont_prog = NULL;
      VIM_CLEAR(block->b_syn_linecont_pat);
  #ifdef FEAT_FOLDING
      block->b_syn_folditems = 0;
  #endif
      clear_string_option(&block->b_syn_isk);
  
      // free the stored states
      syn_stack_free_all(block);
      invalidate_current_state();
  
      // Reset the counter for ":syn include"
      running_syn_inc_tag = 0;
  }
  
  /*
   * Get rid of ownsyntax for window "wp".
   */
      void
  reset_synblock(win_T *wp)
  {
      if (wp->w_s != &wp->w_buffer->b_s)
      {
  	syntax_clear(wp->w_s);
  	vim_free(wp->w_s);
  	wp->w_s = &wp->w_buffer->b_s;
      }
  }
  
  /*
   * Clear syncing info for one buffer.
   */
      static void
  syntax_sync_clear(void)
  {
      int i;
  
      // free the syntax patterns
      for (i = curwin->w_s->b_syn_patterns.ga_len; --i >= 0; )
  	if (SYN_ITEMS(curwin->w_s)[i].sp_syncing)
  	    syn_remove_pattern(curwin->w_s, i);
  
      curwin->w_s->b_syn_sync_flags = 0;
      curwin->w_s->b_syn_sync_minlines = 0;
      curwin->w_s->b_syn_sync_maxlines = 0;
      curwin->w_s->b_syn_sync_linebreaks = 0;
  
      vim_regfree(curwin->w_s->b_syn_linecont_prog);
      curwin->w_s->b_syn_linecont_prog = NULL;
      VIM_CLEAR(curwin->w_s->b_syn_linecont_pat);
      clear_string_option(&curwin->w_s->b_syn_isk);
  
      syn_stack_free_all(curwin->w_s);	// Need to recompute all syntax.
  }
  
  /*
   * Remove one pattern from the buffer's pattern list.
   */
      static void
  syn_remove_pattern(
      synblock_T	*block,
      int		idx)
  {
      synpat_T	*spp;
  
      spp = &(SYN_ITEMS(block)[idx]);
  #ifdef FEAT_FOLDING
      if (spp->sp_flags & HL_FOLD)
  	--block->b_syn_folditems;
  #endif
      syn_clear_pattern(block, idx);
      mch_memmove(spp, spp + 1,
  		   sizeof(synpat_T) * (block->b_syn_patterns.ga_len - idx - 1));
      --block->b_syn_patterns.ga_len;
  }
  
  /*
   * Clear and free one syntax pattern.  When clearing all, must be called from
   * last to first!
   */
      static void
  syn_clear_pattern(synblock_T *block, int i)
  {
      vim_free(SYN_ITEMS(block)[i].sp_pattern);
      vim_regfree(SYN_ITEMS(block)[i].sp_prog);
      // Only free sp_cont_list and sp_next_list of first start pattern
      if (i == 0 || SYN_ITEMS(block)[i - 1].sp_type != SPTYPE_START)
      {
  	vim_free(SYN_ITEMS(block)[i].sp_cont_list);
  	vim_free(SYN_ITEMS(block)[i].sp_next_list);
  	vim_free(SYN_ITEMS(block)[i].sp_syn.cont_in_list);
      }
  }
  
  /*
   * Clear and free one syntax cluster.
   */
      static void
  syn_clear_cluster(synblock_T *block, int i)
  {
      vim_free(SYN_CLSTR(block)[i].scl_name);
      vim_free(SYN_CLSTR(block)[i].scl_name_u);
      vim_free(SYN_CLSTR(block)[i].scl_list);
  }
  
  /*
   * Handle ":syntax clear" command.
   */
      static void
  syn_cmd_clear(exarg_T *eap, int syncing)
  {
      char_u	*arg = eap->arg;
      char_u	*arg_end;
      int		id;
  
      eap->nextcmd = find_nextcmd(arg);
      if (eap->skip)
  	return;
  
      /*
       * We have to disable this within ":syn include @group filename",
       * because otherwise @group would get deleted.
       * Only required for Vim 5.x syntax files, 6.0 ones don't contain ":syn
       * clear".
       */
      if (curwin->w_s->b_syn_topgrp != 0)
  	return;
  
      if (ends_excmd2(eap->cmd, arg))
      {
  	/*
  	 * No argument: Clear all syntax items.
  	 */
  	if (syncing)
  	    syntax_sync_clear();
  	else
  	{
  	    syntax_clear(curwin->w_s);
  	    if (curwin->w_s == &curwin->w_buffer->b_s)
  		do_unlet((char_u *)"b:current_syntax", TRUE);
  	    do_unlet((char_u *)"w:current_syntax", TRUE);
  	}
      }
      else
      {
  	/*
  	 * Clear the group IDs that are in the argument.
  	 */
  	while (!ends_excmd2(eap->cmd, arg))
  	{
  	    arg_end = skiptowhite(arg);
  	    if (*arg == '@')
  	    {
  		id = syn_scl_namen2id(arg + 1, (int)(arg_end - arg - 1));
  		if (id == 0)
  		{
  		    semsg(_("E391: No such syntax cluster: %s"), arg);
  		    break;
  		}
  		else
  		{
  		    /*
  		     * We can't physically delete a cluster without changing
  		     * the IDs of other clusters, so we do the next best thing
  		     * and make it empty.
  		     */
  		    short scl_id = id - SYNID_CLUSTER;
  
  		    VIM_CLEAR(SYN_CLSTR(curwin->w_s)[scl_id].scl_list);
  		}
  	    }
  	    else
  	    {
  		id = syn_namen2id(arg, (int)(arg_end - arg));
  		if (id == 0)
  		{
  		    semsg(_(e_nogroup), arg);
  		    break;
  		}
  		else
  		    syn_clear_one(id, syncing);
  	    }
  	    arg = skipwhite(arg_end);
  	}
      }
      redraw_curbuf_later(SOME_VALID);
      syn_stack_free_all(curwin->w_s);		// Need to recompute all syntax.
  }
  
  /*
   * Clear one syntax group for the current buffer.
   */
      static void
  syn_clear_one(int id, int syncing)
  {
      synpat_T	*spp;
      int		idx;
  
      // Clear keywords only when not ":syn sync clear group-name"
      if (!syncing)
      {
  	(void)syn_clear_keyword(id, &curwin->w_s->b_keywtab);
  	(void)syn_clear_keyword(id, &curwin->w_s->b_keywtab_ic);
      }
  
      // clear the patterns for "id"
      for (idx = curwin->w_s->b_syn_patterns.ga_len; --idx >= 0; )
      {
  	spp = &(SYN_ITEMS(curwin->w_s)[idx]);
  	if (spp->sp_syn.id != id || spp->sp_syncing != syncing)
  	    continue;
  	syn_remove_pattern(curwin->w_s, idx);
      }
  }
  
  /*
   * Handle ":syntax on" command.
   */
      static void
  syn_cmd_on(exarg_T *eap, int syncing UNUSED)
  {
      syn_cmd_onoff(eap, "syntax");
  }
  
  /*
   * Handle ":syntax enable" command.
   */
      static void
  syn_cmd_enable(exarg_T *eap, int syncing UNUSED)
  {
      set_internal_string_var((char_u *)"syntax_cmd", (char_u *)"enable");
      syn_cmd_onoff(eap, "syntax");
      do_unlet((char_u *)"g:syntax_cmd", TRUE);
  }
  
  /*
   * Handle ":syntax reset" command.
   * It actually resets highlighting, not syntax.
   */
      static void
  syn_cmd_reset(exarg_T *eap, int syncing UNUSED)
  {
      eap->nextcmd = check_nextcmd(eap->arg);
      if (!eap->skip)
      {
  	set_internal_string_var((char_u *)"syntax_cmd", (char_u *)"reset");
  	do_cmdline_cmd((char_u *)"runtime! syntax/syncolor.vim");
  	do_unlet((char_u *)"g:syntax_cmd", TRUE);
      }
  }
  
  /*
   * Handle ":syntax manual" command.
   */
      static void
  syn_cmd_manual(exarg_T *eap, int syncing UNUSED)
  {
      syn_cmd_onoff(eap, "manual");
  }
  
  /*
   * Handle ":syntax off" command.
   */
      static void
  syn_cmd_off(exarg_T *eap, int syncing UNUSED)
  {
      syn_cmd_onoff(eap, "nosyntax");
  }
  
      static void
  syn_cmd_onoff(exarg_T *eap, char *name)
  {
      char_u	buf[100];
  
      eap->nextcmd = check_nextcmd(eap->arg);
      if (!eap->skip)
      {
  	STRCPY(buf, "so ");
  	vim_snprintf((char *)buf + 3, sizeof(buf) - 3, SYNTAX_FNAME, name);
  	do_cmdline_cmd(buf);
      }
  }
  
  /*
   * Handle ":syntax [list]" command: list current syntax words.
   */
      static void
  syn_cmd_list(
      exarg_T	*eap,
      int		syncing)	    // when TRUE: list syncing items
  {
      char_u	*arg = eap->arg;
      int		id;
      char_u	*arg_end;
  
      eap->nextcmd = find_nextcmd(arg);
      if (eap->skip)
  	return;
  
      if (!syntax_present(curwin))
      {
  	msg(_(msg_no_items));
  	return;
      }
  
      if (syncing)
      {
  	if (curwin->w_s->b_syn_sync_flags & SF_CCOMMENT)
  	{
  	    msg_puts(_("syncing on C-style comments"));
  	    syn_lines_msg();
  	    syn_match_msg();
  	    return;
  	}
  	else if (!(curwin->w_s->b_syn_sync_flags & SF_MATCH))
  	{
  	    if (curwin->w_s->b_syn_sync_minlines == 0)
  		msg_puts(_("no syncing"));
  	    else
  	    {
  		msg_puts(_("syncing starts "));
  		msg_outnum(curwin->w_s->b_syn_sync_minlines);
  		msg_puts(_(" lines before top line"));
  		syn_match_msg();
  	    }
  	    return;
  	}
  	msg_puts_title(_("\n--- Syntax sync items ---"));
  	if (curwin->w_s->b_syn_sync_minlines > 0
  		|| curwin->w_s->b_syn_sync_maxlines > 0
  		|| curwin->w_s->b_syn_sync_linebreaks > 0)
  	{
  	    msg_puts(_("\nsyncing on items"));
  	    syn_lines_msg();
  	    syn_match_msg();
  	}
      }
      else
  	msg_puts_title(_("\n--- Syntax items ---"));
      if (ends_excmd2(eap->cmd, arg))
      {
  	/*
  	 * No argument: List all group IDs and all syntax clusters.
  	 */
  	for (id = 1; id <= highlight_num_groups() && !got_int; ++id)
  	    syn_list_one(id, syncing, FALSE);
  	for (id = 0; id < curwin->w_s->b_syn_clusters.ga_len && !got_int; ++id)
  	    syn_list_cluster(id);
      }
      else
      {
  	/*
  	 * List the group IDs and syntax clusters that are in the argument.
  	 */
  	while (!ends_excmd2(eap->cmd, arg) && !got_int)
  	{
  	    arg_end = skiptowhite(arg);
  	    if (*arg == '@')
  	    {
  		id = syn_scl_namen2id(arg + 1, (int)(arg_end - arg - 1));
  		if (id == 0)
  		    semsg(_("E392: No such syntax cluster: %s"), arg);
  		else
  		    syn_list_cluster(id - SYNID_CLUSTER);
  	    }
  	    else
  	    {
  		id = syn_namen2id(arg, (int)(arg_end - arg));
  		if (id == 0)
  		    semsg(_(e_nogroup), arg);
  		else
  		    syn_list_one(id, syncing, TRUE);
  	    }
  	    arg = skipwhite(arg_end);
  	}
      }
      eap->nextcmd = check_nextcmd(arg);
  }
  
      static void
  syn_lines_msg(void)
  {
      if (curwin->w_s->b_syn_sync_maxlines > 0
  				      || curwin->w_s->b_syn_sync_minlines > 0)
      {
  	msg_puts("; ");
  	if (curwin->w_s->b_syn_sync_minlines > 0)
  	{
  	    msg_puts(_("minimal "));
  	    msg_outnum(curwin->w_s->b_syn_sync_minlines);
  	    if (curwin->w_s->b_syn_sync_maxlines)
  		msg_puts(", ");
  	}
  	if (curwin->w_s->b_syn_sync_maxlines > 0)
  	{
  	    msg_puts(_("maximal "));
  	    msg_outnum(curwin->w_s->b_syn_sync_maxlines);
  	}
  	msg_puts(_(" lines before top line"));
      }
  }
  
      static void
  syn_match_msg(void)
  {
      if (curwin->w_s->b_syn_sync_linebreaks > 0)
      {
  	msg_puts(_("; match "));
  	msg_outnum(curwin->w_s->b_syn_sync_linebreaks);
  	msg_puts(_(" line breaks"));
      }
  }
  
  static int  last_matchgroup;
  
  struct name_list
  {
      int		flag;
      char	*name;
  };
  
  static void syn_list_flags(struct name_list *nl, int flags, int attr);
  
  /*
   * List one syntax item, for ":syntax" or "syntax list syntax_name".
   */
      static void
  syn_list_one(
      int		id,
      int		syncing,	    // when TRUE: list syncing items
      int		link_only)	    // when TRUE; list link-only too
  {
      int		attr;
      int		idx;
      int		did_header = FALSE;
      synpat_T	*spp;
      static struct name_list namelist1[] =
  		{
  		    {HL_DISPLAY, "display"},
  		    {HL_CONTAINED, "contained"},
  		    {HL_ONELINE, "oneline"},
  		    {HL_KEEPEND, "keepend"},
  		    {HL_EXTEND, "extend"},
  		    {HL_EXCLUDENL, "excludenl"},
  		    {HL_TRANSP, "transparent"},
  		    {HL_FOLD, "fold"},
  #ifdef FEAT_CONCEAL
  		    {HL_CONCEAL, "conceal"},
  		    {HL_CONCEALENDS, "concealends"},
  #endif
  		    {0, NULL}
  		};
      static struct name_list namelist2[] =
  		{
  		    {HL_SKIPWHITE, "skipwhite"},
  		    {HL_SKIPNL, "skipnl"},
  		    {HL_SKIPEMPTY, "skipempty"},
  		    {0, NULL}
  		};
  
      attr = HL_ATTR(HLF_D);		// highlight like directories
  
      // list the keywords for "id"
      if (!syncing)
      {
  	did_header = syn_list_keywords(id, &curwin->w_s->b_keywtab, FALSE, attr);
  	did_header = syn_list_keywords(id, &curwin->w_s->b_keywtab_ic,
  							    did_header, attr);
      }
  
      // list the patterns for "id"
      for (idx = 0; idx < curwin->w_s->b_syn_patterns.ga_len && !got_int; ++idx)
      {
  	spp = &(SYN_ITEMS(curwin->w_s)[idx]);
  	if (spp->sp_syn.id != id || spp->sp_syncing != syncing)
  	    continue;
  
  	(void)syn_list_header(did_header, 999, id);
  	did_header = TRUE;
  	last_matchgroup = 0;
  	if (spp->sp_type == SPTYPE_MATCH)
  	{
  	    put_pattern("match", ' ', spp, attr);
  	    msg_putchar(' ');
  	}
  	else if (spp->sp_type == SPTYPE_START)
  	{
  	    while (SYN_ITEMS(curwin->w_s)[idx].sp_type == SPTYPE_START)
  		put_pattern("start", '=', &SYN_ITEMS(curwin->w_s)[idx++], attr);
  	    if (SYN_ITEMS(curwin->w_s)[idx].sp_type == SPTYPE_SKIP)
  		put_pattern("skip", '=', &SYN_ITEMS(curwin->w_s)[idx++], attr);
  	    while (idx < curwin->w_s->b_syn_patterns.ga_len
  			  && SYN_ITEMS(curwin->w_s)[idx].sp_type == SPTYPE_END)
  		put_pattern("end", '=', &SYN_ITEMS(curwin->w_s)[idx++], attr);
  	    --idx;
  	    msg_putchar(' ');
  	}
  	syn_list_flags(namelist1, spp->sp_flags, attr);
  
  	if (spp->sp_cont_list != NULL)
  	    put_id_list((char_u *)"contains", spp->sp_cont_list, attr);
  
  	if (spp->sp_syn.cont_in_list != NULL)
  	    put_id_list((char_u *)"containedin",
  					      spp->sp_syn.cont_in_list, attr);
  
  	if (spp->sp_next_list != NULL)
  	{
  	    put_id_list((char_u *)"nextgroup", spp->sp_next_list, attr);
  	    syn_list_flags(namelist2, spp->sp_flags, attr);
  	}
  	if (spp->sp_flags & (HL_SYNC_HERE|HL_SYNC_THERE))
  	{
  	    if (spp->sp_flags & HL_SYNC_HERE)
  		msg_puts_attr("grouphere", attr);
  	    else
  		msg_puts_attr("groupthere", attr);
  	    msg_putchar(' ');
  	    if (spp->sp_sync_idx >= 0)
  		msg_outtrans(highlight_group_name(SYN_ITEMS(curwin->w_s)
  				   [spp->sp_sync_idx].sp_syn.id - 1));
  	    else
  		msg_puts("NONE");
  	    msg_putchar(' ');
  	}
      }
  
      // list the link, if there is one
      if (highlight_link_id(id - 1) && (did_header || link_only) && !got_int)
      {
  	(void)syn_list_header(did_header, 999, id);
  	msg_puts_attr("links to", attr);
  	msg_putchar(' ');
  	msg_outtrans(highlight_group_name(highlight_link_id(id - 1) - 1));
      }
  }
  
      static void
  syn_list_flags(struct name_list *nlist, int flags, int attr)
  {
      int		i;
  
      for (i = 0; nlist[i].flag != 0; ++i)
  	if (flags & nlist[i].flag)
  	{
  	    msg_puts_attr(nlist[i].name, attr);
  	    msg_putchar(' ');
  	}
  }
  
  /*
   * List one syntax cluster, for ":syntax" or "syntax list syntax_name".
   */
      static void
  syn_list_cluster(int id)
  {
      int	    endcol = 15;
  
      // slight hack:  roughly duplicate the guts of syn_list_header()
      msg_putchar('\n');
      msg_outtrans(SYN_CLSTR(curwin->w_s)[id].scl_name);
  
      if (msg_col >= endcol)	// output at least one space
  	endcol = msg_col + 1;
      if (Columns <= endcol)	// avoid hang for tiny window
  	endcol = Columns - 1;
  
      msg_advance(endcol);
      if (SYN_CLSTR(curwin->w_s)[id].scl_list != NULL)
      {
  	put_id_list((char_u *)"cluster", SYN_CLSTR(curwin->w_s)[id].scl_list,
  		    HL_ATTR(HLF_D));
      }
      else
      {
  	msg_puts_attr("cluster", HL_ATTR(HLF_D));
  	msg_puts("=NONE");
      }
  }
  
      static void
  put_id_list(char_u *name, short *list, int attr)
  {
      short		*p;
  
      msg_puts_attr((char *)name, attr);
      msg_putchar('=');
      for (p = list; *p; ++p)
      {
  	if (*p >= SYNID_ALLBUT && *p < SYNID_TOP)
  	{
  	    if (p[1])
  		msg_puts("ALLBUT");
  	    else
  		msg_puts("ALL");
  	}
  	else if (*p >= SYNID_TOP && *p < SYNID_CONTAINED)
  	{
  	    msg_puts("TOP");
  	}
  	else if (*p >= SYNID_CONTAINED && *p < SYNID_CLUSTER)
  	{
  	    msg_puts("CONTAINED");
  	}
  	else if (*p >= SYNID_CLUSTER)
  	{
  	    short scl_id = *p - SYNID_CLUSTER;
  
  	    msg_putchar('@');
  	    msg_outtrans(SYN_CLSTR(curwin->w_s)[scl_id].scl_name);
  	}
  	else
  	    msg_outtrans(highlight_group_name(*p - 1));
  	if (p[1])
  	    msg_putchar(',');
      }
      msg_putchar(' ');
  }
  
      static void
  put_pattern(
      char	*s,
      int		c,
      synpat_T	*spp,
      int		attr)
  {
      long	n;
      int		mask;
      int		first;
      static char	*sepchars = "/+=-#@\"|'^&";
      int		i;
  
      // May have to write "matchgroup=group"
      if (last_matchgroup != spp->sp_syn_match_id)
      {
  	last_matchgroup = spp->sp_syn_match_id;
  	msg_puts_attr("matchgroup", attr);
  	msg_putchar('=');
  	if (last_matchgroup == 0)
  	    msg_outtrans((char_u *)"NONE");
  	else
  	    msg_outtrans(highlight_group_name(last_matchgroup - 1));
  	msg_putchar(' ');
      }
  
      // output the name of the pattern and an '=' or ' '
      msg_puts_attr(s, attr);
      msg_putchar(c);
  
      // output the pattern, in between a char that is not in the pattern
      for (i = 0; vim_strchr(spp->sp_pattern, sepchars[i]) != NULL; )
  	if (sepchars[++i] == NUL)
  	{
  	    i = 0;	// no good char found, just use the first one
  	    break;
  	}
      msg_putchar(sepchars[i]);
      msg_outtrans(spp->sp_pattern);
      msg_putchar(sepchars[i]);
  
      // output any pattern options
      first = TRUE;
      for (i = 0; i < SPO_COUNT; ++i)
      {
  	mask = (1 << i);
  	if (spp->sp_off_flags & (mask + (mask << SPO_COUNT)))
  	{
  	    if (!first)
  		msg_putchar(',');	// separate with commas
  	    msg_puts(spo_name_tab[i]);
  	    n = spp->sp_offsets[i];
  	    if (i != SPO_LC_OFF)
  	    {
  		if (spp->sp_off_flags & mask)
  		    msg_putchar('s');
  		else
  		    msg_putchar('e');
  		if (n > 0)
  		    msg_putchar('+');
  	    }
  	    if (n || i == SPO_LC_OFF)
  		msg_outnum(n);
  	    first = FALSE;
  	}
      }
      msg_putchar(' ');
  }
  
  /*
   * List or clear the keywords for one syntax group.
   * Return TRUE if the header has been printed.
   */
      static int
  syn_list_keywords(
      int		id,
      hashtab_T	*ht,
      int		did_header,		// header has already been printed
      int		attr)
  {
      int		outlen;
      hashitem_T	*hi;
      keyentry_T	*kp;
      int		todo;
      int		prev_contained = 0;
      short	*prev_next_list = NULL;
      short	*prev_cont_in_list = NULL;
      int		prev_skipnl = 0;
      int		prev_skipwhite = 0;
      int		prev_skipempty = 0;
  
      /*
       * Unfortunately, this list of keywords is not sorted on alphabet but on
       * hash value...
       */
      todo = (int)ht->ht_used;
      for (hi = ht->ht_array; todo > 0 && !got_int; ++hi)
      {
  	if (!HASHITEM_EMPTY(hi))
  	{
  	    --todo;
  	    for (kp = HI2KE(hi); kp != NULL && !got_int; kp = kp->ke_next)
  	    {
  		if (kp->k_syn.id == id)
  		{
  		    if (prev_contained != (kp->flags & HL_CONTAINED)
  			    || prev_skipnl != (kp->flags & HL_SKIPNL)
  			    || prev_skipwhite != (kp->flags & HL_SKIPWHITE)
  			    || prev_skipempty != (kp->flags & HL_SKIPEMPTY)
  			    || prev_cont_in_list != kp->k_syn.cont_in_list
  			    || prev_next_list != kp->next_list)
  			outlen = 9999;
  		    else
  			outlen = (int)STRLEN(kp->keyword);
  		    // output "contained" and "nextgroup" on each line
  		    if (syn_list_header(did_header, outlen, id))
  		    {
  			prev_contained = 0;
  			prev_next_list = NULL;
  			prev_cont_in_list = NULL;
  			prev_skipnl = 0;
  			prev_skipwhite = 0;
  			prev_skipempty = 0;
  		    }
  		    did_header = TRUE;
  		    if (prev_contained != (kp->flags & HL_CONTAINED))
  		    {
  			msg_puts_attr("contained", attr);
  			msg_putchar(' ');
  			prev_contained = (kp->flags & HL_CONTAINED);
  		    }
  		    if (kp->k_syn.cont_in_list != prev_cont_in_list)
  		    {
  			put_id_list((char_u *)"containedin",
  						kp->k_syn.cont_in_list, attr);
  			msg_putchar(' ');
  			prev_cont_in_list = kp->k_syn.cont_in_list;
  		    }
  		    if (kp->next_list != prev_next_list)
  		    {
  			put_id_list((char_u *)"nextgroup", kp->next_list, attr);
  			msg_putchar(' ');
  			prev_next_list = kp->next_list;
  			if (kp->flags & HL_SKIPNL)
  			{
  			    msg_puts_attr("skipnl", attr);
  			    msg_putchar(' ');
  			    prev_skipnl = (kp->flags & HL_SKIPNL);
  			}
  			if (kp->flags & HL_SKIPWHITE)
  			{
  			    msg_puts_attr("skipwhite", attr);
  			    msg_putchar(' ');
  			    prev_skipwhite = (kp->flags & HL_SKIPWHITE);
  			}
  			if (kp->flags & HL_SKIPEMPTY)
  			{
  			    msg_puts_attr("skipempty", attr);
  			    msg_putchar(' ');
  			    prev_skipempty = (kp->flags & HL_SKIPEMPTY);
  			}
  		    }
  		    msg_outtrans(kp->keyword);
  		}
  	    }
  	}
      }
  
      return did_header;
  }
  
      static void
  syn_clear_keyword(int id, hashtab_T *ht)
  {
      hashitem_T	*hi;
      keyentry_T	*kp;
      keyentry_T	*kp_prev;
      keyentry_T	*kp_next;
      int		todo;
  
      hash_lock(ht);
      todo = (int)ht->ht_used;
      for (hi = ht->ht_array; todo > 0; ++hi)
      {
  	if (!HASHITEM_EMPTY(hi))
  	{
  	    --todo;
  	    kp_prev = NULL;
  	    for (kp = HI2KE(hi); kp != NULL; )
  	    {
  		if (kp->k_syn.id == id)
  		{
  		    kp_next = kp->ke_next;
  		    if (kp_prev == NULL)
  		    {
  			if (kp_next == NULL)
  			    hash_remove(ht, hi);
  			else
  			    hi->hi_key = KE2HIKEY(kp_next);
  		    }
  		    else
  			kp_prev->ke_next = kp_next;
  		    vim_free(kp->next_list);
  		    vim_free(kp->k_syn.cont_in_list);
  		    vim_free(kp);
  		    kp = kp_next;
  		}
  		else
  		{
  		    kp_prev = kp;
  		    kp = kp->ke_next;
  		}
  	    }
  	}
      }
      hash_unlock(ht);
  }
  
  /*
   * Clear a whole keyword table.
   */
      static void
  clear_keywtab(hashtab_T *ht)
  {
      hashitem_T	*hi;
      int		todo;
      keyentry_T	*kp;
      keyentry_T	*kp_next;
  
      todo = (int)ht->ht_used;
      for (hi = ht->ht_array; todo > 0; ++hi)
      {
  	if (!HASHITEM_EMPTY(hi))
  	{
  	    --todo;
  	    for (kp = HI2KE(hi); kp != NULL; kp = kp_next)
  	    {
  		kp_next = kp->ke_next;
  		vim_free(kp->next_list);
  		vim_free(kp->k_syn.cont_in_list);
  		vim_free(kp);
  	    }
  	}
      }
      hash_clear(ht);
      hash_init(ht);
  }
  
  /*
   * Add a keyword to the list of keywords.
   */
      static void
  add_keyword(
      char_u	*name,	    // name of keyword
      int		id,	    // group ID for this keyword
      int		flags,	    // flags for this keyword
      short	*cont_in_list, // containedin for this keyword
      short	*next_list, // nextgroup for this keyword
      int		conceal_char)
  {
      keyentry_T	*kp;
      hashtab_T	*ht;
      hashitem_T	*hi;
      char_u	*name_ic;
      long_u	hash;
      char_u	name_folded[MAXKEYWLEN + 1];
  
      if (curwin->w_s->b_syn_ic)
  	name_ic = str_foldcase(name, (int)STRLEN(name),
  						 name_folded, MAXKEYWLEN + 1);
      else
  	name_ic = name;
      kp = alloc(offsetof(keyentry_T, keyword) + STRLEN(name_ic) + 1);
      if (kp == NULL)
  	return;
      STRCPY(kp->keyword, name_ic);
      kp->k_syn.id = id;
      kp->k_syn.inc_tag = current_syn_inc_tag;
      kp->flags = flags;
      kp->k_char = conceal_char;
      kp->k_syn.cont_in_list = copy_id_list(cont_in_list);
      if (cont_in_list != NULL)
  	curwin->w_s->b_syn_containedin = TRUE;
      kp->next_list = copy_id_list(next_list);
  
      if (curwin->w_s->b_syn_ic)
  	ht = &curwin->w_s->b_keywtab_ic;
      else
  	ht = &curwin->w_s->b_keywtab;
  
      hash = hash_hash(kp->keyword);
      hi = hash_lookup(ht, kp->keyword, hash);
      if (HASHITEM_EMPTY(hi))
      {
  	// new keyword, add to hashtable
  	kp->ke_next = NULL;
  	hash_add_item(ht, hi, kp->keyword, hash);
      }
      else
      {
  	// keyword already exists, prepend to list
  	kp->ke_next = HI2KE(hi);
  	hi->hi_key = KE2HIKEY(kp);
      }
  }
  
  /*
   * Get the start and end of the group name argument.
   * Return a pointer to the first argument.
   * Return NULL if the end of the command was found instead of further args.
   */
      static char_u *
  get_group_name(
      char_u	*arg,		// start of the argument
      char_u	**name_end)	// pointer to end of the name
  {
      char_u	*rest;
  
      *name_end = skiptowhite(arg);
      rest = skipwhite(*name_end);
  
      /*
       * Check if there are enough arguments.  The first argument may be a
       * pattern, where '|' is allowed, so only check for NUL.
       */
      if (ends_excmd(*arg) || *rest == NUL)
  	return NULL;
      return rest;
  }
  
  /*
   * Check for syntax command option arguments.
   * This can be called at any place in the list of arguments, and just picks
   * out the arguments that are known.  Can be called several times in a row to
   * collect all options in between other arguments.
   * Return a pointer to the next argument (which isn't an option).
   * Return NULL for any error;
   */
      static char_u *
  get_syn_options(
      char_u	    *start,		// next argument to be checked
      syn_opt_arg_T   *opt,		// various things
      int		    *conceal_char UNUSED,
      int		    skip)		// TRUE if skipping over command
  {
      char_u	*arg = start;
      char_u	*gname_start, *gname;
      int		syn_id;
      int		len;
      char	*p;
      int		i;
      int		fidx;
      static struct flag
      {
  	char	*name;
  	int	argtype;
  	int	flags;
      } flagtab[] = { {"cCoOnNtTaAiInNeEdD",	0,	HL_CONTAINED},
  		    {"oOnNeElLiInNeE",		0,	HL_ONELINE},
  		    {"kKeEeEpPeEnNdD",		0,	HL_KEEPEND},
  		    {"eExXtTeEnNdD",		0,	HL_EXTEND},
  		    {"eExXcClLuUdDeEnNlL",	0,	HL_EXCLUDENL},
  		    {"tTrRaAnNsSpPaArReEnNtT",	0,	HL_TRANSP},
  		    {"sSkKiIpPnNlL",		0,	HL_SKIPNL},
  		    {"sSkKiIpPwWhHiItTeE",	0,	HL_SKIPWHITE},
  		    {"sSkKiIpPeEmMpPtTyY",	0,	HL_SKIPEMPTY},
  		    {"gGrRoOuUpPhHeErReE",	0,	HL_SYNC_HERE},
  		    {"gGrRoOuUpPtThHeErReE",	0,	HL_SYNC_THERE},
  		    {"dDiIsSpPlLaAyY",		0,	HL_DISPLAY},
  		    {"fFoOlLdD",		0,	HL_FOLD},
  		    {"cCoOnNcCeEaAlL",		0,	HL_CONCEAL},
  		    {"cCoOnNcCeEaAlLeEnNdDsS",	0,	HL_CONCEALENDS},
  		    {"cCcChHaArR",		11,	0},
  		    {"cCoOnNtTaAiInNsS",	1,	0},
  		    {"cCoOnNtTaAiInNeEdDiInN",	2,	0},
  		    {"nNeExXtTgGrRoOuUpP",	3,	0},
  		};
      static char *first_letters = "cCoOkKeEtTsSgGdDfFnN";
  
      if (arg == NULL)		// already detected error
  	return NULL;
  
  #ifdef FEAT_CONCEAL
      if (curwin->w_s->b_syn_conceal)
  	opt->flags |= HL_CONCEAL;
  #endif
  
      for (;;)
      {
  	/*
  	 * This is used very often when a large number of keywords is defined.
  	 * Need to skip quickly when no option name is found.
  	 * Also avoid tolower(), it's slow.
  	 */
  	if (strchr(first_letters, *arg) == NULL)
  	    break;
  
  	for (fidx = sizeof(flagtab) / sizeof(struct flag); --fidx >= 0; )
  	{
  	    p = flagtab[fidx].name;
  	    for (i = 0, len = 0; p[i] != NUL; i += 2, ++len)
  		if (arg[len] != p[i] && arg[len] != p[i + 1])
  		    break;
  	    if (p[i] == NUL && (VIM_ISWHITE(arg[len])
  				    || (flagtab[fidx].argtype > 0
  					 ? arg[len] == '='
  					 : ends_excmd2(start, arg + len))))
  	    {
  		if (opt->keyword
  			&& (flagtab[fidx].flags == HL_DISPLAY
  			    || flagtab[fidx].flags == HL_FOLD
  			    || flagtab[fidx].flags == HL_EXTEND))
  		    // treat "display", "fold" and "extend" as a keyword
  		    fidx = -1;
  		break;
  	    }
  	}
  	if (fidx < 0)	    // no match found
  	    break;
  
  	if (flagtab[fidx].argtype == 1)
  	{
  	    if (!opt->has_cont_list)
  	    {
  		emsg(_("E395: contains argument not accepted here"));
  		return NULL;
  	    }
  	    if (get_id_list(&arg, 8, &opt->cont_list, skip) == FAIL)
  		return NULL;
  	}
  	else if (flagtab[fidx].argtype == 2)
  	{
  	    if (get_id_list(&arg, 11, &opt->cont_in_list, skip) == FAIL)
  		return NULL;
  	}
  	else if (flagtab[fidx].argtype == 3)
  	{
  	    if (get_id_list(&arg, 9, &opt->next_list, skip) == FAIL)
  		return NULL;
  	}
  	else if (flagtab[fidx].argtype == 11 && arg[5] == '=')
  	{
  	    // cchar=?
  	    if (has_mbyte)
  	    {
  #ifdef FEAT_CONCEAL
  		*conceal_char = mb_ptr2char(arg + 6);
  #endif
  		arg += mb_ptr2len(arg + 6) - 1;
  	    }
  	    else
  	    {
  #ifdef FEAT_CONCEAL
  		*conceal_char = arg[6];
  #else
  		;
  #endif
  	    }
  #ifdef FEAT_CONCEAL
  	    if (!vim_isprintc_strict(*conceal_char))
  	    {
  		emsg(_("E844: invalid cchar value"));
  		return NULL;
  	    }
  #endif
  	    arg = skipwhite(arg + 7);
  	}
  	else
  	{
  	    opt->flags |= flagtab[fidx].flags;
  	    arg = skipwhite(arg + len);
  
  	    if (flagtab[fidx].flags == HL_SYNC_HERE
  		    || flagtab[fidx].flags == HL_SYNC_THERE)
  	    {
  		if (opt->sync_idx == NULL)
  		{
  		    emsg(_("E393: group[t]here not accepted here"));
  		    return NULL;
  		}
  		gname_start = arg;
  		arg = skiptowhite(arg);
  		if (gname_start == arg)
  		    return NULL;
  		gname = vim_strnsave(gname_start, (int)(arg - gname_start));
  		if (gname == NULL)
  		    return NULL;
  		if (STRCMP(gname, "NONE") == 0)
  		    *opt->sync_idx = NONE_IDX;
  		else
  		{
  		    syn_id = syn_name2id(gname);
  		    for (i = curwin->w_s->b_syn_patterns.ga_len; --i >= 0; )
  			if (SYN_ITEMS(curwin->w_s)[i].sp_syn.id == syn_id
  			      && SYN_ITEMS(curwin->w_s)[i].sp_type == SPTYPE_START)
  			{
  			    *opt->sync_idx = i;
  			    break;
  			}
  		    if (i < 0)
  		    {
  			semsg(_("E394: Didn't find region item for %s"), gname);
  			vim_free(gname);
  			return NULL;
  		    }
  		}
  
  		vim_free(gname);
  		arg = skipwhite(arg);
  	    }
  #ifdef FEAT_FOLDING
  	    else if (flagtab[fidx].flags == HL_FOLD
  						&& foldmethodIsSyntax(curwin))
  		// Need to update folds later.
  		foldUpdateAll(curwin);
  #endif
  	}
      }
  
      return arg;
  }
  
  /*
   * Adjustments to syntax item when declared in a ":syn include"'d file.
   * Set the contained flag, and if the item is not already contained, add it
   * to the specified top-level group, if any.
   */
      static void
  syn_incl_toplevel(int id, int *flagsp)
  {
      if ((*flagsp & HL_CONTAINED) || curwin->w_s->b_syn_topgrp == 0)
  	return;
      *flagsp |= HL_CONTAINED;
      if (curwin->w_s->b_syn_topgrp >= SYNID_CLUSTER)
      {
  	// We have to alloc this, because syn_combine_list() will free it.
  	short	    *grp_list = ALLOC_MULT(short, 2);
  	int	    tlg_id = curwin->w_s->b_syn_topgrp - SYNID_CLUSTER;
  
  	if (grp_list != NULL)
  	{
  	    grp_list[0] = id;
  	    grp_list[1] = 0;
  	    syn_combine_list(&SYN_CLSTR(curwin->w_s)[tlg_id].scl_list,
  						       &grp_list, CLUSTER_ADD);
  	}
      }
  }
  
  /*
   * Handle ":syntax include [@{group-name}] filename" command.
   */
      static void
  syn_cmd_include(exarg_T *eap, int syncing UNUSED)
  {
      char_u	*arg = eap->arg;
      int		sgl_id = 1;
      char_u	*group_name_end;
      char_u	*rest;
      char	*errormsg = NULL;
      int		prev_toplvl_grp;
      int		prev_syn_inc_tag;
      int		source = FALSE;
  
      eap->nextcmd = find_nextcmd(arg);
      if (eap->skip)
  	return;
  
      if (arg[0] == '@')
      {
  	++arg;
  	rest = get_group_name(arg, &group_name_end);
  	if (rest == NULL)
  	{
  	    emsg(_("E397: Filename required"));
  	    return;
  	}
  	sgl_id = syn_check_cluster(arg, (int)(group_name_end - arg));
  	if (sgl_id == 0)
  	    return;
  	// separate_nextcmd() and expand_filename() depend on this
  	eap->arg = rest;
      }
  
      /*
       * Everything that's left, up to the next command, should be the
       * filename to include.
       */
      eap->argt |= (EX_XFILE | EX_NOSPC);
      separate_nextcmd(eap);
      if (*eap->arg == '<' || *eap->arg == '$' || mch_isFullName(eap->arg))
      {
  	// For an absolute path, "$VIM/..." or "<sfile>.." we ":source" the
  	// file.  Need to expand the file name first.  In other cases
  	// ":runtime!" is used.
  	source = TRUE;
  	if (expand_filename(eap, syn_cmdlinep, &errormsg) == FAIL)
  	{
  	    if (errormsg != NULL)
  		emsg(errormsg);
  	    return;
  	}
      }
  
      /*
       * Save and restore the existing top-level grouplist id and ":syn
       * include" tag around the actual inclusion.
       */
      if (running_syn_inc_tag >= MAX_SYN_INC_TAG)
      {
  	emsg(_("E847: Too many syntax includes"));
  	return;
      }
      prev_syn_inc_tag = current_syn_inc_tag;
      current_syn_inc_tag = ++running_syn_inc_tag;
      prev_toplvl_grp = curwin->w_s->b_syn_topgrp;
      curwin->w_s->b_syn_topgrp = sgl_id;
      if (source ? do_source(eap->arg, FALSE, DOSO_NONE, NULL) == FAIL
  				: source_runtime(eap->arg, DIP_ALL) == FAIL)
  	semsg(_(e_notopen), eap->arg);
      curwin->w_s->b_syn_topgrp = prev_toplvl_grp;
      current_syn_inc_tag = prev_syn_inc_tag;
  }
  
  /*
   * Handle ":syntax keyword {group-name} [{option}] keyword .." command.
   */
      static void
  syn_cmd_keyword(exarg_T *eap, int syncing UNUSED)
  {
      char_u	*arg = eap->arg;
      char_u	*group_name_end;
      int		syn_id;
      char_u	*rest;
      char_u	*keyword_copy = NULL;
      char_u	*p;
      char_u	*kw;
      syn_opt_arg_T syn_opt_arg;
      int		cnt;
      int		conceal_char = NUL;
  
      rest = get_group_name(arg, &group_name_end);
  
      if (rest != NULL)
      {
  	if (eap->skip)
  	    syn_id = -1;
  	else
  	    syn_id = syn_check_group(arg, (int)(group_name_end - arg));
  	if (syn_id != 0)
  	    // allocate a buffer, for removing backslashes in the keyword
  	    keyword_copy = alloc(STRLEN(rest) + 1);
  	if (keyword_copy != NULL)
  	{
  	    syn_opt_arg.flags = 0;
  	    syn_opt_arg.keyword = TRUE;
  	    syn_opt_arg.sync_idx = NULL;
  	    syn_opt_arg.has_cont_list = FALSE;
  	    syn_opt_arg.cont_in_list = NULL;
  	    syn_opt_arg.next_list = NULL;
  
  	    /*
  	     * The options given apply to ALL keywords, so all options must be
  	     * found before keywords can be created.
  	     * 1: collect the options and copy the keywords to keyword_copy.
  	     */
  	    cnt = 0;
  	    p = keyword_copy;
  	    for ( ; rest != NULL && !ends_excmd2(eap->arg, rest);
  							rest = skipwhite(rest))
  	    {
  		rest = get_syn_options(rest, &syn_opt_arg, &conceal_char,
  								    eap->skip);
  		if (rest == NULL || ends_excmd2(eap->arg, rest))
  		    break;
  		// Copy the keyword, removing backslashes, and add a NUL.
  		while (*rest != NUL && !VIM_ISWHITE(*rest))
  		{
  		    if (*rest == '\\' && rest[1] != NUL)
  			++rest;
  		    *p++ = *rest++;
  		}
  		*p++ = NUL;
  		++cnt;
  	    }
  
  	    if (!eap->skip)
  	    {
  		// Adjust flags for use of ":syn include".
  		syn_incl_toplevel(syn_id, &syn_opt_arg.flags);
  
  		/*
  		 * 2: Add an entry for each keyword.
  		 */
  		for (kw = keyword_copy; --cnt >= 0; kw += STRLEN(kw) + 1)
  		{
  		    for (p = vim_strchr(kw, '['); ; )
  		    {
  			if (p != NULL)
  			    *p = NUL;
  			add_keyword(kw, syn_id, syn_opt_arg.flags,
  				syn_opt_arg.cont_in_list,
  					 syn_opt_arg.next_list, conceal_char);
  			if (p == NULL)
  			    break;
  			if (p[1] == NUL)
  			{
  			    semsg(_("E789: Missing ']': %s"), kw);
  			    goto error;
  			}
  			if (p[1] == ']')
  			{
  			    if (p[2] != NUL)
  			    {
  				semsg(_("E890: trailing char after ']': %s]%s"),
  								kw, &p[2]);
  				goto error;
  			    }
  			    kw = p + 1;		// skip over the "]"
  			    break;
  			}
  			if (has_mbyte)
  			{
  			    int l = (*mb_ptr2len)(p + 1);
  
  			    mch_memmove(p, p + 1, l);
  			    p += l;
  			}
  			else
  			{
  			    p[0] = p[1];
  			    ++p;
  			}
  		    }
  		}
  	    }
  error:
  	    vim_free(keyword_copy);
  	    vim_free(syn_opt_arg.cont_in_list);
  	    vim_free(syn_opt_arg.next_list);
  	}
      }
  
      if (rest != NULL)
  	eap->nextcmd = check_nextcmd(rest);
      else
  	semsg(_(e_invarg2), arg);
  
      redraw_curbuf_later(SOME_VALID);
      syn_stack_free_all(curwin->w_s);		// Need to recompute all syntax.
  }
  
  /*
   * Handle ":syntax match {name} [{options}] {pattern} [{options}]".
   *
   * Also ":syntax sync match {name} [[grouphere | groupthere] {group-name}] .."
   */
      static void
  syn_cmd_match(
      exarg_T	*eap,
      int		syncing)	    // TRUE for ":syntax sync match .. "
  {
      char_u	*arg = eap->arg;
      char_u	*group_name_end;
      char_u	*rest;
      synpat_T	item;		// the item found in the line
      int		syn_id;
      int		idx;
      syn_opt_arg_T syn_opt_arg;
      int		sync_idx = 0;
      int		conceal_char = NUL;
      int		orig_called_emsg = called_emsg;
  
      // Isolate the group name, check for validity
      rest = get_group_name(arg, &group_name_end);
  
      // Get options before the pattern
      syn_opt_arg.flags = 0;
      syn_opt_arg.keyword = FALSE;
      syn_opt_arg.sync_idx = syncing ? &sync_idx : NULL;
      syn_opt_arg.has_cont_list = TRUE;
      syn_opt_arg.cont_list = NULL;
      syn_opt_arg.cont_in_list = NULL;
      syn_opt_arg.next_list = NULL;
      rest = get_syn_options(rest, &syn_opt_arg, &conceal_char, eap->skip);
  
      // get the pattern.
      init_syn_patterns();
      CLEAR_FIELD(item);
      rest = get_syn_pattern(rest, &item);
      if (vim_regcomp_had_eol() && !(syn_opt_arg.flags & HL_EXCLUDENL))
  	syn_opt_arg.flags |= HL_HAS_EOL;
  
      // Get options after the pattern
      rest = get_syn_options(rest, &syn_opt_arg, &conceal_char, eap->skip);
  
      if (rest != NULL)		// all arguments are valid
      {
  	/*
  	 * Check for trailing command and illegal trailing arguments.
  	 */
  	eap->nextcmd = check_nextcmd(rest);
  	if (!ends_excmd2(eap->cmd, rest) || eap->skip)
  	    rest = NULL;
  	else if (ga_grow(&curwin->w_s->b_syn_patterns, 1) != FAIL
  		&& (syn_id = syn_check_group(arg,
  					   (int)(group_name_end - arg))) != 0)
  	{
  	    syn_incl_toplevel(syn_id, &syn_opt_arg.flags);
  	    /*
  	     * Store the pattern in the syn_items list
  	     */
  	    idx = curwin->w_s->b_syn_patterns.ga_len;
  	    SYN_ITEMS(curwin->w_s)[idx] = item;
  	    SYN_ITEMS(curwin->w_s)[idx].sp_syncing = syncing;
  	    SYN_ITEMS(curwin->w_s)[idx].sp_type = SPTYPE_MATCH;
  	    SYN_ITEMS(curwin->w_s)[idx].sp_syn.id = syn_id;
  	    SYN_ITEMS(curwin->w_s)[idx].sp_syn.inc_tag = current_syn_inc_tag;
  	    SYN_ITEMS(curwin->w_s)[idx].sp_flags = syn_opt_arg.flags;
  	    SYN_ITEMS(curwin->w_s)[idx].sp_sync_idx = sync_idx;
  	    SYN_ITEMS(curwin->w_s)[idx].sp_cont_list = syn_opt_arg.cont_list;
  	    SYN_ITEMS(curwin->w_s)[idx].sp_syn.cont_in_list =
  						     syn_opt_arg.cont_in_list;
  #ifdef FEAT_CONCEAL
  	    SYN_ITEMS(curwin->w_s)[idx].sp_cchar = conceal_char;
  #endif
  	    if (syn_opt_arg.cont_in_list != NULL)
  		curwin->w_s->b_syn_containedin = TRUE;
  	    SYN_ITEMS(curwin->w_s)[idx].sp_next_list = syn_opt_arg.next_list;
  	    ++curwin->w_s->b_syn_patterns.ga_len;
  
  	    // remember that we found a match for syncing on
  	    if (syn_opt_arg.flags & (HL_SYNC_HERE|HL_SYNC_THERE))
  		curwin->w_s->b_syn_sync_flags |= SF_MATCH;
  #ifdef FEAT_FOLDING
  	    if (syn_opt_arg.flags & HL_FOLD)
  		++curwin->w_s->b_syn_folditems;
  #endif
  
  	    redraw_curbuf_later(SOME_VALID);
  	    syn_stack_free_all(curwin->w_s);	// Need to recompute all syntax.
  	    return;	// don't free the progs and patterns now
  	}
      }
  
      /*
       * Something failed, free the allocated memory.
       */
      vim_regfree(item.sp_prog);
      vim_free(item.sp_pattern);
      vim_free(syn_opt_arg.cont_list);
      vim_free(syn_opt_arg.cont_in_list);
      vim_free(syn_opt_arg.next_list);
  
      if (rest == NULL && called_emsg == orig_called_emsg)
  	semsg(_(e_invarg2), arg);
  }
  
  /*
   * Handle ":syntax region {group-name} [matchgroup={group-name}]
   *		start {start} .. [skip {skip}] end {end} .. [{options}]".
   */
      static void
  syn_cmd_region(
      exarg_T	*eap,
      int		syncing)	    // TRUE for ":syntax sync region .."
  {
      char_u		*arg = eap->arg;
      char_u		*group_name_end;
      char_u		*rest;			// next arg, NULL on error
      char_u		*key_end;
      char_u		*key = NULL;
      char_u		*p;
      int			item;
  #define ITEM_START	    0
  #define ITEM_SKIP	    1
  #define ITEM_END	    2
  #define ITEM_MATCHGROUP	    3
      struct pat_ptr
      {
  	synpat_T	*pp_synp;		// pointer to syn_pattern
  	int		pp_matchgroup_id;	// matchgroup ID
  	struct pat_ptr	*pp_next;		// pointer to next pat_ptr
      }			*(pat_ptrs[3]);
  					// patterns found in the line
      struct pat_ptr	*ppp;
      struct pat_ptr	*ppp_next;
      int			pat_count = 0;		// nr of syn_patterns found
      int			syn_id;
      int			matchgroup_id = 0;
      int			not_enough = FALSE;	// not enough arguments
      int			illegal = FALSE;	// illegal arguments
      int			success = FALSE;
      int			idx;
      syn_opt_arg_T	syn_opt_arg;
      int			conceal_char = NUL;
  
      // Isolate the group name, check for validity
      rest = get_group_name(arg, &group_name_end);
  
      pat_ptrs[0] = NULL;
      pat_ptrs[1] = NULL;
      pat_ptrs[2] = NULL;
  
      init_syn_patterns();
  
      syn_opt_arg.flags = 0;
      syn_opt_arg.keyword = FALSE;
      syn_opt_arg.sync_idx = NULL;
      syn_opt_arg.has_cont_list = TRUE;
      syn_opt_arg.cont_list = NULL;
      syn_opt_arg.cont_in_list = NULL;
      syn_opt_arg.next_list = NULL;
  
      /*
       * get the options, patterns and matchgroup.
       */
      while (rest != NULL && !ends_excmd2(eap->cmd, rest))
      {
  	// Check for option arguments
  	rest = get_syn_options(rest, &syn_opt_arg, &conceal_char, eap->skip);
  	if (rest == NULL || ends_excmd2(eap->cmd, rest))
  	    break;
  
  	// must be a pattern or matchgroup then
  	key_end = rest;
  	while (*key_end && !VIM_ISWHITE(*key_end) && *key_end != '=')
  	    ++key_end;
  	vim_free(key);
  	key = vim_strnsave_up(rest, (int)(key_end - rest));
  	if (key == NULL)			// out of memory
  	{
  	    rest = NULL;
  	    break;
  	}
  	if (STRCMP(key, "MATCHGROUP") == 0)
  	    item = ITEM_MATCHGROUP;
  	else if (STRCMP(key, "START") == 0)
  	    item = ITEM_START;
  	else if (STRCMP(key, "END") == 0)
  	    item = ITEM_END;
  	else if (STRCMP(key, "SKIP") == 0)
  	{
  	    if (pat_ptrs[ITEM_SKIP] != NULL)	// one skip pattern allowed
  	    {
  		illegal = TRUE;
  		break;
  	    }
  	    item = ITEM_SKIP;
  	}
  	else
  	    break;
  	rest = skipwhite(key_end);
  	if (*rest != '=')
  	{
  	    rest = NULL;
  	    semsg(_("E398: Missing '=': %s"), arg);
  	    break;
  	}
  	rest = skipwhite(rest + 1);
  	if (*rest == NUL)
  	{
  	    not_enough = TRUE;
  	    break;
  	}
  
  	if (item == ITEM_MATCHGROUP)
  	{
  	    p = skiptowhite(rest);
  	    if ((p - rest == 4 && STRNCMP(rest, "NONE", 4) == 0) || eap->skip)
  		matchgroup_id = 0;
  	    else
  	    {
  		matchgroup_id = syn_check_group(rest, (int)(p - rest));
  		if (matchgroup_id == 0)
  		{
  		    illegal = TRUE;
  		    break;
  		}
  	    }
  	    rest = skipwhite(p);
  	}
  	else
  	{
  	    /*
  	     * Allocate room for a syn_pattern, and link it in the list of
  	     * syn_patterns for this item, at the start (because the list is
  	     * used from end to start).
  	     */
  	    ppp = ALLOC_ONE(struct pat_ptr);
  	    if (ppp == NULL)
  	    {
  		rest = NULL;
  		break;
  	    }
  	    ppp->pp_next = pat_ptrs[item];
  	    pat_ptrs[item] = ppp;
  	    ppp->pp_synp = ALLOC_CLEAR_ONE(synpat_T);
  	    if (ppp->pp_synp == NULL)
  	    {
  		rest = NULL;
  		break;
  	    }
  
  	    /*
  	     * Get the syntax pattern and the following offset(s).
  	     */
  	    // Enable the appropriate \z specials.
  	    if (item == ITEM_START)
  		reg_do_extmatch = REX_SET;
  	    else if (item == ITEM_SKIP || item == ITEM_END)
  		reg_do_extmatch = REX_USE;
  	    rest = get_syn_pattern(rest, ppp->pp_synp);
  	    reg_do_extmatch = 0;
  	    if (item == ITEM_END && vim_regcomp_had_eol()
  				       && !(syn_opt_arg.flags & HL_EXCLUDENL))
  		ppp->pp_synp->sp_flags |= HL_HAS_EOL;
  	    ppp->pp_matchgroup_id = matchgroup_id;
  	    ++pat_count;
  	}
      }
      vim_free(key);
      if (illegal || not_enough)
  	rest = NULL;
  
      /*
       * Must have a "start" and "end" pattern.
       */
      if (rest != NULL && (pat_ptrs[ITEM_START] == NULL ||
  						  pat_ptrs[ITEM_END] == NULL))
      {
  	not_enough = TRUE;
  	rest = NULL;
      }
  
      if (rest != NULL)
      {
  	/*
  	 * Check for trailing garbage or command.
  	 * If OK, add the item.
  	 */
  	eap->nextcmd = check_nextcmd(rest);
  	if (!ends_excmd(*rest) || eap->skip)
  	    rest = NULL;
  	else if (ga_grow(&(curwin->w_s->b_syn_patterns), pat_count) != FAIL
  		&& (syn_id = syn_check_group(arg,
  					   (int)(group_name_end - arg))) != 0)
  	{
  	    syn_incl_toplevel(syn_id, &syn_opt_arg.flags);
  	    /*
  	     * Store the start/skip/end in the syn_items list
  	     */
  	    idx = curwin->w_s->b_syn_patterns.ga_len;
  	    for (item = ITEM_START; item <= ITEM_END; ++item)
  	    {
  		for (ppp = pat_ptrs[item]; ppp != NULL; ppp = ppp->pp_next)
  		{
  		    SYN_ITEMS(curwin->w_s)[idx] = *(ppp->pp_synp);
  		    SYN_ITEMS(curwin->w_s)[idx].sp_syncing = syncing;
  		    SYN_ITEMS(curwin->w_s)[idx].sp_type =
  			    (item == ITEM_START) ? SPTYPE_START :
  			    (item == ITEM_SKIP) ? SPTYPE_SKIP : SPTYPE_END;
  		    SYN_ITEMS(curwin->w_s)[idx].sp_flags |= syn_opt_arg.flags;
  		    SYN_ITEMS(curwin->w_s)[idx].sp_syn.id = syn_id;
  		    SYN_ITEMS(curwin->w_s)[idx].sp_syn.inc_tag =
  							  current_syn_inc_tag;
  		    SYN_ITEMS(curwin->w_s)[idx].sp_syn_match_id =
  							ppp->pp_matchgroup_id;
  #ifdef FEAT_CONCEAL
  		    SYN_ITEMS(curwin->w_s)[idx].sp_cchar = conceal_char;
  #endif
  		    if (item == ITEM_START)
  		    {
  			SYN_ITEMS(curwin->w_s)[idx].sp_cont_list =
  							syn_opt_arg.cont_list;
  			SYN_ITEMS(curwin->w_s)[idx].sp_syn.cont_in_list =
  						     syn_opt_arg.cont_in_list;
  			if (syn_opt_arg.cont_in_list != NULL)
  			    curwin->w_s->b_syn_containedin = TRUE;
  			SYN_ITEMS(curwin->w_s)[idx].sp_next_list =
  							syn_opt_arg.next_list;
  		    }
  		    ++curwin->w_s->b_syn_patterns.ga_len;
  		    ++idx;
  #ifdef FEAT_FOLDING
  		    if (syn_opt_arg.flags & HL_FOLD)
  			++curwin->w_s->b_syn_folditems;
  #endif
  		}
  	    }
  
  	    redraw_curbuf_later(SOME_VALID);
  	    syn_stack_free_all(curwin->w_s);	// Need to recompute all syntax.
  	    success = TRUE;	    // don't free the progs and patterns now
  	}
      }
  
      /*
       * Free the allocated memory.
       */
      for (item = ITEM_START; item <= ITEM_END; ++item)
  	for (ppp = pat_ptrs[item]; ppp != NULL; ppp = ppp_next)
  	{
  	    if (!success && ppp->pp_synp != NULL)
  	    {
  		vim_regfree(ppp->pp_synp->sp_prog);
  		vim_free(ppp->pp_synp->sp_pattern);
  	    }
  	    vim_free(ppp->pp_synp);
  	    ppp_next = ppp->pp_next;
  	    vim_free(ppp);
  	}
  
      if (!success)
      {
  	vim_free(syn_opt_arg.cont_list);
  	vim_free(syn_opt_arg.cont_in_list);
  	vim_free(syn_opt_arg.next_list);
  	if (not_enough)
  	    semsg(_("E399: Not enough arguments: syntax region %s"), arg);
  	else if (illegal || rest == NULL)
  	    semsg(_(e_invarg2), arg);
      }
  }
  
  /*
   * A simple syntax group ID comparison function suitable for use in qsort()
   */
      static int
  syn_compare_stub(const void *v1, const void *v2)
  {
      const short	*s1 = v1;
      const short	*s2 = v2;
  
      return (*s1 > *s2 ? 1 : *s1 < *s2 ? -1 : 0);
  }
  
  /*
   * Combines lists of syntax clusters.
   * *clstr1 and *clstr2 must both be allocated memory; they will be consumed.
   */
      static void
  syn_combine_list(short **clstr1, short **clstr2, int list_op)
  {
      int		count1 = 0;
      int		count2 = 0;
      short	*g1;
      short	*g2;
      short	*clstr = NULL;
      int		count;
      int		round;
  
      /*
       * Handle degenerate cases.
       */
      if (*clstr2 == NULL)
  	return;
      if (*clstr1 == NULL || list_op == CLUSTER_REPLACE)
      {
  	if (list_op == CLUSTER_REPLACE)
  	    vim_free(*clstr1);
  	if (list_op == CLUSTER_REPLACE || list_op == CLUSTER_ADD)
  	    *clstr1 = *clstr2;
  	else
  	    vim_free(*clstr2);
  	return;
      }
  
      for (g1 = *clstr1; *g1; g1++)
  	++count1;
      for (g2 = *clstr2; *g2; g2++)
  	++count2;
  
      /*
       * For speed purposes, sort both lists.
       */
      qsort(*clstr1, (size_t)count1, sizeof(short), syn_compare_stub);
      qsort(*clstr2, (size_t)count2, sizeof(short), syn_compare_stub);
  
      /*
       * We proceed in two passes; in round 1, we count the elements to place
       * in the new list, and in round 2, we allocate and populate the new
       * list.  For speed, we use a mergesort-like method, adding the smaller
       * of the current elements in each list to the new list.
       */
      for (round = 1; round <= 2; round++)
      {
  	g1 = *clstr1;
  	g2 = *clstr2;
  	count = 0;
  
  	/*
  	 * First, loop through the lists until one of them is empty.
  	 */
  	while (*g1 && *g2)
  	{
  	    /*
  	     * We always want to add from the first list.
  	     */
  	    if (*g1 < *g2)
  	    {
  		if (round == 2)
  		    clstr[count] = *g1;
  		count++;
  		g1++;
  		continue;
  	    }
  	    /*
  	     * We only want to add from the second list if we're adding the
  	     * lists.
  	     */
  	    if (list_op == CLUSTER_ADD)
  	    {
  		if (round == 2)
  		    clstr[count] = *g2;
  		count++;
  	    }
  	    if (*g1 == *g2)
  		g1++;
  	    g2++;
  	}
  
  	/*
  	 * Now add the leftovers from whichever list didn't get finished
  	 * first.  As before, we only want to add from the second list if
  	 * we're adding the lists.
  	 */
  	for (; *g1; g1++, count++)
  	    if (round == 2)
  		clstr[count] = *g1;
  	if (list_op == CLUSTER_ADD)
  	    for (; *g2; g2++, count++)
  		if (round == 2)
  		    clstr[count] = *g2;
  
  	if (round == 1)
  	{
  	    /*
  	     * If the group ended up empty, we don't need to allocate any
  	     * space for it.
  	     */
  	    if (count == 0)
  	    {
  		clstr = NULL;
  		break;
  	    }
  	    clstr = ALLOC_MULT(short, count + 1);
  	    if (clstr == NULL)
  		break;
  	    clstr[count] = 0;
  	}
      }
  
      /*
       * Finally, put the new list in place.
       */
      vim_free(*clstr1);
      vim_free(*clstr2);
      *clstr1 = clstr;
  }
  
  /*
   * Lookup a syntax cluster name and return its ID.
   * If it is not found, 0 is returned.
   */
      static int
  syn_scl_name2id(char_u *name)
  {
      int		i;
      char_u	*name_u;
  
      // Avoid using stricmp() too much, it's slow on some systems
      name_u = vim_strsave_up(name);
      if (name_u == NULL)
  	return 0;
      for (i = curwin->w_s->b_syn_clusters.ga_len; --i >= 0; )
  	if (SYN_CLSTR(curwin->w_s)[i].scl_name_u != NULL
  		&& STRCMP(name_u, SYN_CLSTR(curwin->w_s)[i].scl_name_u) == 0)
  	    break;
      vim_free(name_u);
      return (i < 0 ? 0 : i + SYNID_CLUSTER);
  }
  
  /*
   * Like syn_scl_name2id(), but take a pointer + length argument.
   */
      static int
  syn_scl_namen2id(char_u *linep, int len)
  {
      char_u  *name;
      int	    id = 0;
  
      name = vim_strnsave(linep, len);
      if (name != NULL)
      {
  	id = syn_scl_name2id(name);
  	vim_free(name);
      }
      return id;
  }
  
  /*
   * Find syntax cluster name in the table and return its ID.
   * The argument is a pointer to the name and the length of the name.
   * If it doesn't exist yet, a new entry is created.
   * Return 0 for failure.
   */
      static int
  syn_check_cluster(char_u *pp, int len)
  {
      int		id;
      char_u	*name;
  
      name = vim_strnsave(pp, len);
      if (name == NULL)
  	return 0;
  
      id = syn_scl_name2id(name);
      if (id == 0)			// doesn't exist yet
  	id = syn_add_cluster(name);
      else
  	vim_free(name);
      return id;
  }
  
  /*
   * Add new syntax cluster and return its ID.
   * "name" must be an allocated string, it will be consumed.
   * Return 0 for failure.
   */
      static int
  syn_add_cluster(char_u *name)
  {
      int		len;
  
      /*
       * First call for this growarray: init growing array.
       */
      if (curwin->w_s->b_syn_clusters.ga_data == NULL)
      {
  	curwin->w_s->b_syn_clusters.ga_itemsize = sizeof(syn_cluster_T);
  	curwin->w_s->b_syn_clusters.ga_growsize = 10;
      }
  
      len = curwin->w_s->b_syn_clusters.ga_len;
      if (len >= MAX_CLUSTER_ID)
      {
  	emsg(_("E848: Too many syntax clusters"));
  	vim_free(name);
  	return 0;
      }
  
      /*
       * Make room for at least one other cluster entry.
       */
      if (ga_grow(&curwin->w_s->b_syn_clusters, 1) == FAIL)
      {
  	vim_free(name);
  	return 0;
      }
  
      CLEAR_POINTER(&(SYN_CLSTR(curwin->w_s)[len]));
      SYN_CLSTR(curwin->w_s)[len].scl_name = name;
      SYN_CLSTR(curwin->w_s)[len].scl_name_u = vim_strsave_up(name);
      SYN_CLSTR(curwin->w_s)[len].scl_list = NULL;
      ++curwin->w_s->b_syn_clusters.ga_len;
  
      if (STRICMP(name, "Spell") == 0)
  	curwin->w_s->b_spell_cluster_id = len + SYNID_CLUSTER;
      if (STRICMP(name, "NoSpell") == 0)
  	curwin->w_s->b_nospell_cluster_id = len + SYNID_CLUSTER;
  
      return len + SYNID_CLUSTER;
  }
  
  /*
   * Handle ":syntax cluster {cluster-name} [contains={groupname},..]
   *		[add={groupname},..] [remove={groupname},..]".
   */
      static void
  syn_cmd_cluster(exarg_T *eap, int syncing UNUSED)
  {
      char_u	*arg = eap->arg;
      char_u	*group_name_end;
      char_u	*rest;
      int		scl_id;
      short	*clstr_list;
      int		got_clstr = FALSE;
      int		opt_len;
      int		list_op;
  
      eap->nextcmd = find_nextcmd(arg);
      if (eap->skip)
  	return;
  
      rest = get_group_name(arg, &group_name_end);
  
      if (rest != NULL)
      {
  	scl_id = syn_check_cluster(arg, (int)(group_name_end - arg));
  	if (scl_id == 0)
  	    return;
  	scl_id -= SYNID_CLUSTER;
  
  	for (;;)
  	{
  	    if (STRNICMP(rest, "add", 3) == 0
  		    && (VIM_ISWHITE(rest[3]) || rest[3] == '='))
  	    {
  		opt_len = 3;
  		list_op = CLUSTER_ADD;
  	    }
  	    else if (STRNICMP(rest, "remove", 6) == 0
  		    && (VIM_ISWHITE(rest[6]) || rest[6] == '='))
  	    {
  		opt_len = 6;
  		list_op = CLUSTER_SUBTRACT;
  	    }
  	    else if (STRNICMP(rest, "contains", 8) == 0
  			&& (VIM_ISWHITE(rest[8]) || rest[8] == '='))
  	    {
  		opt_len = 8;
  		list_op = CLUSTER_REPLACE;
  	    }
  	    else
  		break;
  
  	    clstr_list = NULL;
  	    if (get_id_list(&rest, opt_len, &clstr_list, eap->skip) == FAIL)
  	    {
  		semsg(_(e_invarg2), rest);
  		break;
  	    }
  	    if (scl_id >= 0)
  		syn_combine_list(&SYN_CLSTR(curwin->w_s)[scl_id].scl_list,
  			     &clstr_list, list_op);
  	    else
  		vim_free(clstr_list);
  	    got_clstr = TRUE;
  	}
  
  	if (got_clstr)
  	{
  	    redraw_curbuf_later(SOME_VALID);
  	    syn_stack_free_all(curwin->w_s);	// Need to recompute all.
  	}
      }
  
      if (!got_clstr)
  	emsg(_("E400: No cluster specified"));
      if (rest == NULL || !ends_excmd2(eap->cmd, rest))
  	semsg(_(e_invarg2), arg);
  }
  
  /*
   * On first call for current buffer: Init growing array.
   */
      static void
  init_syn_patterns(void)
  {
      curwin->w_s->b_syn_patterns.ga_itemsize = sizeof(synpat_T);
      curwin->w_s->b_syn_patterns.ga_growsize = 10;
  }
  
  /*
   * Get one pattern for a ":syntax match" or ":syntax region" command.
   * Stores the pattern and program in a synpat_T.
   * Returns a pointer to the next argument, or NULL in case of an error.
   */
      static char_u *
  get_syn_pattern(char_u *arg, synpat_T *ci)
  {
      char_u	*end;
      int		*p;
      int		idx;
      char_u	*cpo_save;
  
      // need at least three chars
      if (arg == NULL || arg[0] == NUL || arg[1] == NUL || arg[2] == NUL)
  	return NULL;
  
      end = skip_regexp(arg + 1, *arg, TRUE);
      if (*end != *arg)			    // end delimiter not found
      {
  	semsg(_("E401: Pattern delimiter not found: %s"), arg);
  	return NULL;
      }
      // store the pattern and compiled regexp program
      if ((ci->sp_pattern = vim_strnsave(arg + 1, (int)(end - arg - 1))) == NULL)
  	return NULL;
  
      // Make 'cpoptions' empty, to avoid the 'l' flag
      cpo_save = p_cpo;
      p_cpo = (char_u *)"";
      ci->sp_prog = vim_regcomp(ci->sp_pattern, RE_MAGIC);
      p_cpo = cpo_save;
  
      if (ci->sp_prog == NULL)
  	return NULL;
      ci->sp_ic = curwin->w_s->b_syn_ic;
  #ifdef FEAT_PROFILE
      syn_clear_time(&ci->sp_time);
  #endif
  
      /*
       * Check for a match, highlight or region offset.
       */
      ++end;
      do
      {
  	for (idx = SPO_COUNT; --idx >= 0; )
  	    if (STRNCMP(end, spo_name_tab[idx], 3) == 0)
  		break;
  	if (idx >= 0)
  	{
  	    p = &(ci->sp_offsets[idx]);
  	    if (idx != SPO_LC_OFF)
  		switch (end[3])
  		{
  		    case 's':   break;
  		    case 'b':   break;
  		    case 'e':   idx += SPO_COUNT; break;
  		    default:    idx = -1; break;
  		}
  	    if (idx >= 0)
  	    {
  		ci->sp_off_flags |= (1 << idx);
  		if (idx == SPO_LC_OFF)	    // lc=99
  		{
  		    end += 3;
  		    *p = getdigits(&end);
  
  		    // "lc=" offset automatically sets "ms=" offset
  		    if (!(ci->sp_off_flags & (1 << SPO_MS_OFF)))
  		    {
  			ci->sp_off_flags |= (1 << SPO_MS_OFF);
  			ci->sp_offsets[SPO_MS_OFF] = *p;
  		    }
  		}
  		else			    // yy=x+99
  		{
  		    end += 4;
  		    if (*end == '+')
  		    {
  			++end;
  			*p = getdigits(&end);		// positive offset
  		    }
  		    else if (*end == '-')
  		    {
  			++end;
  			*p = -getdigits(&end);		// negative offset
  		    }
  		}
  		if (*end != ',')
  		    break;
  		++end;
  	    }
  	}
      } while (idx >= 0);
  
      if (!ends_excmd2(arg, end) && !VIM_ISWHITE(*end))
      {
  	semsg(_("E402: Garbage after pattern: %s"), arg);
  	return NULL;
      }
      return skipwhite(end);
  }
  
  /*
   * Handle ":syntax sync .." command.
   */
      static void
  syn_cmd_sync(exarg_T *eap, int syncing UNUSED)
  {
      char_u	*arg_start = eap->arg;
      char_u	*arg_end;
      char_u	*key = NULL;
      char_u	*next_arg;
      int		illegal = FALSE;
      int		finished = FALSE;
      long	n;
      char_u	*cpo_save;
  
      if (ends_excmd2(eap->cmd, arg_start))
      {
  	syn_cmd_list(eap, TRUE);
  	return;
      }
  
      while (!ends_excmd2(eap->cmd, arg_start))
      {
  	arg_end = skiptowhite(arg_start);
  	next_arg = skipwhite(arg_end);
  	vim_free(key);
  	key = vim_strnsave_up(arg_start, (int)(arg_end - arg_start));
  	if (STRCMP(key, "CCOMMENT") == 0)
  	{
  	    if (!eap->skip)
  		curwin->w_s->b_syn_sync_flags |= SF_CCOMMENT;
  	    if (!ends_excmd2(eap->cmd, next_arg))
  	    {
  		arg_end = skiptowhite(next_arg);
  		if (!eap->skip)
  		    curwin->w_s->b_syn_sync_id = syn_check_group(next_arg,
  						   (int)(arg_end - next_arg));
  		next_arg = skipwhite(arg_end);
  	    }
  	    else if (!eap->skip)
  		curwin->w_s->b_syn_sync_id = syn_name2id((char_u *)"Comment");
  	}
  	else if (  STRNCMP(key, "LINES", 5) == 0
  		|| STRNCMP(key, "MINLINES", 8) == 0
  		|| STRNCMP(key, "MAXLINES", 8) == 0
  		|| STRNCMP(key, "LINEBREAKS", 10) == 0)
  	{
  	    if (key[4] == 'S')
  		arg_end = key + 6;
  	    else if (key[0] == 'L')
  		arg_end = key + 11;
  	    else
  		arg_end = key + 9;
  	    if (arg_end[-1] != '=' || !VIM_ISDIGIT(*arg_end))
  	    {
  		illegal = TRUE;
  		break;
  	    }
  	    n = getdigits(&arg_end);
  	    if (!eap->skip)
  	    {
  		if (key[4] == 'B')
  		    curwin->w_s->b_syn_sync_linebreaks = n;
  		else if (key[1] == 'A')
  		    curwin->w_s->b_syn_sync_maxlines = n;
  		else
  		    curwin->w_s->b_syn_sync_minlines = n;
  	    }
  	}
  	else if (STRCMP(key, "FROMSTART") == 0)
  	{
  	    if (!eap->skip)
  	    {
  		curwin->w_s->b_syn_sync_minlines = MAXLNUM;
  		curwin->w_s->b_syn_sync_maxlines = 0;
  	    }
  	}
  	else if (STRCMP(key, "LINECONT") == 0)
  	{
  	    if (*next_arg == NUL)	   // missing pattern
  	    {
  		illegal = TRUE;
  		break;
  	    }
  	    if (curwin->w_s->b_syn_linecont_pat != NULL)
  	    {
  		emsg(_("E403: syntax sync: line continuations pattern specified twice"));
  		finished = TRUE;
  		break;
  	    }
  	    arg_end = skip_regexp(next_arg + 1, *next_arg, TRUE);
  	    if (*arg_end != *next_arg)	    // end delimiter not found
  	    {
  		illegal = TRUE;
  		break;
  	    }
  
  	    if (!eap->skip)
  	    {
  		// store the pattern and compiled regexp program
  		if ((curwin->w_s->b_syn_linecont_pat = vim_strnsave(next_arg + 1,
  				      (int)(arg_end - next_arg - 1))) == NULL)
  		{
  		    finished = TRUE;
  		    break;
  		}
  		curwin->w_s->b_syn_linecont_ic = curwin->w_s->b_syn_ic;
  
  		// Make 'cpoptions' empty, to avoid the 'l' flag
  		cpo_save = p_cpo;
  		p_cpo = (char_u *)"";
  		curwin->w_s->b_syn_linecont_prog =
  		       vim_regcomp(curwin->w_s->b_syn_linecont_pat, RE_MAGIC);
  		p_cpo = cpo_save;
  #ifdef FEAT_PROFILE
  		syn_clear_time(&curwin->w_s->b_syn_linecont_time);
  #endif
  
  		if (curwin->w_s->b_syn_linecont_prog == NULL)
  		{
  		    VIM_CLEAR(curwin->w_s->b_syn_linecont_pat);
  		    finished = TRUE;
  		    break;
  		}
  	    }
  	    next_arg = skipwhite(arg_end + 1);
  	}
  	else
  	{
  	    eap->arg = next_arg;
  	    if (STRCMP(key, "MATCH") == 0)
  		syn_cmd_match(eap, TRUE);
  	    else if (STRCMP(key, "REGION") == 0)
  		syn_cmd_region(eap, TRUE);
  	    else if (STRCMP(key, "CLEAR") == 0)
  		syn_cmd_clear(eap, TRUE);
  	    else
  		illegal = TRUE;
  	    finished = TRUE;
  	    break;
  	}
  	arg_start = next_arg;
      }
      vim_free(key);
      if (illegal)
  	semsg(_("E404: Illegal arguments: %s"), arg_start);
      else if (!finished)
      {
  	eap->nextcmd = check_nextcmd(arg_start);
  	redraw_curbuf_later(SOME_VALID);
  	syn_stack_free_all(curwin->w_s);	// Need to recompute all syntax.
      }
  }
  
  /*
   * Convert a line of highlight group names into a list of group ID numbers.
   * "arg" should point to the "contains" or "nextgroup" keyword.
   * "arg" is advanced to after the last group name.
   * Careful: the argument is modified (NULs added).
   * returns FAIL for some error, OK for success.
   */
      static int
  get_id_list(
      char_u	**arg,
      int		keylen,		// length of keyword
      short	**list,		// where to store the resulting list, if not
  				// NULL, the list is silently skipped!
      int		skip)
  {
      char_u	*p = NULL;
      char_u	*end;
      int		round;
      int		count;
      int		total_count = 0;
      short	*retval = NULL;
      char_u	*name;
      regmatch_T	regmatch;
      int		id;
      int		i;
      int		failed = FALSE;
  
      /*
       * We parse the list twice:
       * round == 1: count the number of items, allocate the array.
       * round == 2: fill the array with the items.
       * In round 1 new groups may be added, causing the number of items to
       * grow when a regexp is used.  In that case round 1 is done once again.
       */
      for (round = 1; round <= 2; ++round)
      {
  	/*
  	 * skip "contains"
  	 */
  	p = skipwhite(*arg + keylen);
  	if (*p != '=')
  	{
  	    semsg(_("E405: Missing equal sign: %s"), *arg);
  	    break;
  	}
  	p = skipwhite(p + 1);
  	if (ends_excmd2(*arg, p))
  	{
  	    semsg(_("E406: Empty argument: %s"), *arg);
  	    break;
  	}
  
  	/*
  	 * parse the arguments after "contains"
  	 */
  	count = 0;
  	while (!ends_excmd2(*arg, p))
  	{
  	    for (end = p; *end && !VIM_ISWHITE(*end) && *end != ','; ++end)
  		;
  	    name = alloc(end - p + 3);	    // leave room for "^$"
  	    if (name == NULL)
  	    {
  		failed = TRUE;
  		break;
  	    }
  	    vim_strncpy(name + 1, p, end - p);
  	    if (       STRCMP(name + 1, "ALLBUT") == 0
  		    || STRCMP(name + 1, "ALL") == 0
  		    || STRCMP(name + 1, "TOP") == 0
  		    || STRCMP(name + 1, "CONTAINED") == 0)
  	    {
  		if (TOUPPER_ASC(**arg) != 'C')
  		{
  		    semsg(_("E407: %s not allowed here"), name + 1);
  		    failed = TRUE;
  		    vim_free(name);
  		    break;
  		}
  		if (count != 0)
  		{
  		    semsg(_("E408: %s must be first in contains list"),
  								     name + 1);
  		    failed = TRUE;
  		    vim_free(name);
  		    break;
  		}
  		if (name[1] == 'A')
  		    id = SYNID_ALLBUT;
  		else if (name[1] == 'T')
  		    id = SYNID_TOP;
  		else
  		    id = SYNID_CONTAINED;
  		id += current_syn_inc_tag;
  	    }
  	    else if (name[1] == '@')
  	    {
  		if (skip)
  		    id = -1;
  		else
  		    id = syn_check_cluster(name + 2, (int)(end - p - 1));
  	    }
  	    else
  	    {
  		/*
  		 * Handle full group name.
  		 */
  		if (vim_strpbrk(name + 1, (char_u *)"\\.*^$~[") == NULL)
  		    id = syn_check_group(name + 1, (int)(end - p));
  		else
  		{
  		    /*
  		     * Handle match of regexp with group names.
  		     */
  		    *name = '^';
  		    STRCAT(name, "$");
  		    regmatch.regprog = vim_regcomp(name, RE_MAGIC);
  		    if (regmatch.regprog == NULL)
  		    {
  			failed = TRUE;
  			vim_free(name);
  			break;
  		    }
  
  		    regmatch.rm_ic = TRUE;
  		    id = 0;
  		    for (i = highlight_num_groups(); --i >= 0; )
  		    {
  			if (vim_regexec(&regmatch, highlight_group_name(i),
  								  (colnr_T)0))
  			{
  			    if (round == 2)
  			    {
  				// Got more items than expected; can happen
  				// when adding items that match:
  				// "contains=a.*b,axb".
  				// Go back to first round
  				if (count >= total_count)
  				{
  				    vim_free(retval);
  				    round = 1;
  				}
  				else
  				    retval[count] = i + 1;
  			    }
  			    ++count;
  			    id = -1;	    // remember that we found one
  			}
  		    }
  		    vim_regfree(regmatch.regprog);
  		}
  	    }
  	    vim_free(name);
  	    if (id == 0)
  	    {
  		semsg(_("E409: Unknown group name: %s"), p);
  		failed = TRUE;
  		break;
  	    }
  	    if (id > 0)
  	    {
  		if (round == 2)
  		{
  		    // Got more items than expected, go back to first round
  		    if (count >= total_count)
  		    {
  			vim_free(retval);
  			round = 1;
  		    }
  		    else
  			retval[count] = id;
  		}
  		++count;
  	    }
  	    p = skipwhite(end);
  	    if (*p != ',')
  		break;
  	    p = skipwhite(p + 1);	// skip comma in between arguments
  	}
  	if (failed)
  	    break;
  	if (round == 1)
  	{
  	    retval = ALLOC_MULT(short, count + 1);
  	    if (retval == NULL)
  		break;
  	    retval[count] = 0;	    // zero means end of the list
  	    total_count = count;
  	}
      }
  
      *arg = p;
      if (failed || retval == NULL)
      {
  	vim_free(retval);
  	return FAIL;
      }
  
      if (*list == NULL)
  	*list = retval;
      else
  	vim_free(retval);	// list already found, don't overwrite it
  
      return OK;
  }
  
  /*
   * Make a copy of an ID list.
   */
      static short *
  copy_id_list(short *list)
  {
      int	    len;
      int	    count;
      short   *retval;
  
      if (list == NULL)
  	return NULL;
  
      for (count = 0; list[count]; ++count)
  	;
      len = (count + 1) * sizeof(short);
      retval = alloc(len);
      if (retval != NULL)
  	mch_memmove(retval, list, (size_t)len);
  
      return retval;
  }
  
  /*
   * Check if syntax group "ssp" is in the ID list "list" of "cur_si".
   * "cur_si" can be NULL if not checking the "containedin" list.
   * Used to check if a syntax item is in the "contains" or "nextgroup" list of
   * the current item.
   * This function is called very often, keep it fast!!
   */
      static int
  in_id_list(
      stateitem_T	*cur_si,	// current item or NULL
      short	*list,		// id list
      struct sp_syn *ssp,		// group id and ":syn include" tag of group
      int		contained)	// group id is contained
  {
      int		retval;
      short	*scl_list;
      short	item;
      short	id = ssp->id;
      static int	depth = 0;
      int		r;
  
      // If ssp has a "containedin" list and "cur_si" is in it, return TRUE.
      if (cur_si != NULL && ssp->cont_in_list != NULL
  					    && !(cur_si->si_flags & HL_MATCH))
      {
  	// Ignore transparent items without a contains argument.  Double check
  	// that we don't go back past the first one.
  	while ((cur_si->si_flags & HL_TRANS_CONT)
  		&& cur_si > (stateitem_T *)(current_state.ga_data))
  	    --cur_si;
  	// cur_si->si_idx is -1 for keywords, these never contain anything.
  	if (cur_si->si_idx >= 0 && in_id_list(NULL, ssp->cont_in_list,
  		&(SYN_ITEMS(syn_block)[cur_si->si_idx].sp_syn),
  		  SYN_ITEMS(syn_block)[cur_si->si_idx].sp_flags & HL_CONTAINED))
  	    return TRUE;
      }
  
      if (list == NULL)
  	return FALSE;
  
      /*
       * If list is ID_LIST_ALL, we are in a transparent item that isn't
       * inside anything.  Only allow not-contained groups.
       */
      if (list == ID_LIST_ALL)
  	return !contained;
  
      /*
       * If the first item is "ALLBUT", return TRUE if "id" is NOT in the
       * contains list.  We also require that "id" is at the same ":syn include"
       * level as the list.
       */
      item = *list;
      if (item >= SYNID_ALLBUT && item < SYNID_CLUSTER)
      {
  	if (item < SYNID_TOP)
  	{
  	    // ALL or ALLBUT: accept all groups in the same file
  	    if (item - SYNID_ALLBUT != ssp->inc_tag)
  		return FALSE;
  	}
  	else if (item < SYNID_CONTAINED)
  	{
  	    // TOP: accept all not-contained groups in the same file
  	    if (item - SYNID_TOP != ssp->inc_tag || contained)
  		return FALSE;
  	}
  	else
  	{
  	    // CONTAINED: accept all contained groups in the same file
  	    if (item - SYNID_CONTAINED != ssp->inc_tag || !contained)
  		return FALSE;
  	}
  	item = *++list;
  	retval = FALSE;
      }
      else
  	retval = TRUE;
  
      /*
       * Return "retval" if id is in the contains list.
       */
      while (item != 0)
      {
  	if (item == id)
  	    return retval;
  	if (item >= SYNID_CLUSTER)
  	{
  	    scl_list = SYN_CLSTR(syn_block)[item - SYNID_CLUSTER].scl_list;
  	    // restrict recursiveness to 30 to avoid an endless loop for a
  	    // cluster that includes itself (indirectly)
  	    if (scl_list != NULL && depth < 30)
  	    {
  		++depth;
  		r = in_id_list(NULL, scl_list, ssp, contained);
  		--depth;
  		if (r)
  		    return retval;
  	    }
  	}
  	item = *++list;
      }
      return !retval;
  }
  
  struct subcommand
  {
      char    *name;			// subcommand name
      void    (*func)(exarg_T *, int);	// function to call
  };
  
  static struct subcommand subcommands[] =
  {
      {"case",		syn_cmd_case},
      {"clear",		syn_cmd_clear},
      {"cluster",		syn_cmd_cluster},
      {"conceal",		syn_cmd_conceal},
      {"enable",		syn_cmd_enable},
      {"include",		syn_cmd_include},
      {"iskeyword",	syn_cmd_iskeyword},
      {"keyword",		syn_cmd_keyword},
      {"list",		syn_cmd_list},
      {"manual",		syn_cmd_manual},
      {"match",		syn_cmd_match},
      {"on",		syn_cmd_on},
      {"off",		syn_cmd_off},
      {"region",		syn_cmd_region},
      {"reset",		syn_cmd_reset},
      {"spell",		syn_cmd_spell},
      {"sync",		syn_cmd_sync},
      {"",		syn_cmd_list},
      {NULL, NULL}
  };
  
  /*
   * ":syntax".
   * This searches the subcommands[] table for the subcommand name, and calls a
   * syntax_subcommand() function to do the rest.
   */
      void
  ex_syntax(exarg_T *eap)
  {
      char_u	*arg = eap->arg;
      char_u	*subcmd_end;
      char_u	*subcmd_name;
      int		i;
  
      syn_cmdlinep = eap->cmdlinep;
  
      // isolate subcommand name
      for (subcmd_end = arg; ASCII_ISALPHA(*subcmd_end); ++subcmd_end)
  	;
      subcmd_name = vim_strnsave(arg, (int)(subcmd_end - arg));
      if (subcmd_name != NULL)
      {
  	if (eap->skip)		// skip error messages for all subcommands
  	    ++emsg_skip;
  	for (i = 0; ; ++i)
  	{
  	    if (subcommands[i].name == NULL)
  	    {
  		semsg(_("E410: Invalid :syntax subcommand: %s"), subcmd_name);
  		break;
  	    }
  	    if (STRCMP(subcmd_name, (char_u *)subcommands[i].name) == 0)
  	    {
  		eap->arg = skipwhite(subcmd_end);
  		(subcommands[i].func)(eap, FALSE);
  		break;
  	    }
  	}
  	vim_free(subcmd_name);
  	if (eap->skip)
  	    --emsg_skip;
      }
  }
  
      void
  ex_ownsyntax(exarg_T *eap)
  {
      char_u	*old_value;
      char_u	*new_value;
  
      if (curwin->w_s == &curwin->w_buffer->b_s)
      {
  	curwin->w_s = ALLOC_ONE(synblock_T);
  	memset(curwin->w_s, 0, sizeof(synblock_T));
  	hash_init(&curwin->w_s->b_keywtab);
  	hash_init(&curwin->w_s->b_keywtab_ic);
  #ifdef FEAT_SPELL
  	// TODO: keep the spell checking as it was.
  	curwin->w_p_spell = FALSE;	// No spell checking
  	clear_string_option(&curwin->w_s->b_p_spc);
  	clear_string_option(&curwin->w_s->b_p_spf);
  	clear_string_option(&curwin->w_s->b_p_spl);
  #endif
  	clear_string_option(&curwin->w_s->b_syn_isk);
      }
  
      // save value of b:current_syntax
      old_value = get_var_value((char_u *)"b:current_syntax");
      if (old_value != NULL)
  	old_value = vim_strsave(old_value);
  
      // Apply the "syntax" autocommand event, this finds and loads the syntax
      // file.
      apply_autocmds(EVENT_SYNTAX, eap->arg, curbuf->b_fname, TRUE, curbuf);
  
      // move value of b:current_syntax to w:current_syntax
      new_value = get_var_value((char_u *)"b:current_syntax");
      if (new_value != NULL)
  	set_internal_string_var((char_u *)"w:current_syntax", new_value);
  
      // restore value of b:current_syntax
      if (old_value == NULL)
  	do_unlet((char_u *)"b:current_syntax", TRUE);
      else
      {
  	set_internal_string_var((char_u *)"b:current_syntax", old_value);
  	vim_free(old_value);
      }
  }
  
      int
  syntax_present(win_T *win)
  {
      return (win->w_s->b_syn_patterns.ga_len != 0
  	    || win->w_s->b_syn_clusters.ga_len != 0
  	    || win->w_s->b_keywtab.ht_used > 0
  	    || win->w_s->b_keywtab_ic.ht_used > 0);
  }
  
  
  static enum
  {
      EXP_SUBCMD,	    // expand ":syn" sub-commands
      EXP_CASE,	    // expand ":syn case" arguments
      EXP_SPELL,	    // expand ":syn spell" arguments
      EXP_SYNC	    // expand ":syn sync" arguments
  } expand_what;
  
  /*
   * Reset include_link, include_default, include_none to 0.
   * Called when we are done expanding.
   */
      void
  reset_expand_highlight(void)
  {
      include_link = include_default = include_none = 0;
  }
  
  /*
   * Handle command line completion for :match and :echohl command: Add "None"
   * as highlight group.
   */
      void
  set_context_in_echohl_cmd(expand_T *xp, char_u *arg)
  {
      xp->xp_context = EXPAND_HIGHLIGHT;
      xp->xp_pattern = arg;
      include_none = 1;
  }
  
  /*
   * Handle command line completion for :syntax command.
   */
      void
  set_context_in_syntax_cmd(expand_T *xp, char_u *arg)
  {
      char_u	*p;
  
      // Default: expand subcommands
      xp->xp_context = EXPAND_SYNTAX;
      expand_what = EXP_SUBCMD;
      xp->xp_pattern = arg;
      include_link = 0;
      include_default = 0;
  
      // (part of) subcommand already typed
      if (*arg != NUL)
      {
  	p = skiptowhite(arg);
  	if (*p != NUL)		    // past first word
  	{
  	    xp->xp_pattern = skipwhite(p);
  	    if (*skiptowhite(xp->xp_pattern) != NUL)
  		xp->xp_context = EXPAND_NOTHING;
  	    else if (STRNICMP(arg, "case", p - arg) == 0)
  		expand_what = EXP_CASE;
  	    else if (STRNICMP(arg, "spell", p - arg) == 0)
  		expand_what = EXP_SPELL;
  	    else if (STRNICMP(arg, "sync", p - arg) == 0)
  		expand_what = EXP_SYNC;
  	    else if (  STRNICMP(arg, "keyword", p - arg) == 0
  		    || STRNICMP(arg, "region", p - arg) == 0
  		    || STRNICMP(arg, "match", p - arg) == 0
  		    || STRNICMP(arg, "list", p - arg) == 0)
  		xp->xp_context = EXPAND_HIGHLIGHT;
  	    else
  		xp->xp_context = EXPAND_NOTHING;
  	}
      }
  }
  
  /*
   * Function given to ExpandGeneric() to obtain the list syntax names for
   * expansion.
   */
      char_u *
  get_syntax_name(expand_T *xp UNUSED, int idx)
  {
      switch (expand_what)
      {
  	case EXP_SUBCMD:
  	    return (char_u *)subcommands[idx].name;
  	case EXP_CASE:
  	{
  	    static char *case_args[] = {"match", "ignore", NULL};
  	    return (char_u *)case_args[idx];
  	}
  	case EXP_SPELL:
  	{
  	    static char *spell_args[] =
  		{"toplevel", "notoplevel", "default", NULL};
  	    return (char_u *)spell_args[idx];
  	}
  	case EXP_SYNC:
  	{
  	    static char *sync_args[] =
  		{"ccomment", "clear", "fromstart",
  		 "linebreaks=", "linecont", "lines=", "match",
  		 "maxlines=", "minlines=", "region", NULL};
  	    return (char_u *)sync_args[idx];
  	}
      }
      return NULL;
  }
  
  
  /*
   * Function called for expression evaluation: get syntax ID at file position.
   */
      int
  syn_get_id(
      win_T	*wp,
      long	lnum,
      colnr_T	col,
      int		trans,	     // remove transparency
      int		*spellp,     // return: can do spell checking
      int		keep_state)  // keep state of char at "col"
  {
      // When the position is not after the current position and in the same
      // line of the same buffer, need to restart parsing.
      if (wp->w_buffer != syn_buf
  	    || lnum != current_lnum
  	    || col < current_col)
  	syntax_start(wp, lnum);
      else if (wp->w_buffer == syn_buf
  	    && lnum == current_lnum
  	    && col > current_col)
  	// next_match may not be correct when moving around, e.g. with the
  	// "skip" expression in searchpair()
  	next_match_idx = -1;
  
      (void)get_syntax_attr(col, spellp, keep_state);
  
      return (trans ? current_trans_id : current_id);
  }
  
  #if defined(FEAT_CONCEAL) || defined(PROTO)
  /*
   * Get extra information about the syntax item.  Must be called right after
   * get_syntax_attr().
   * Stores the current item sequence nr in "*seqnrp".
   * Returns the current flags.
   */
      int
  get_syntax_info(int *seqnrp)
  {
      *seqnrp = current_seqnr;
      return current_flags;
  }
  
  /*
   * Return conceal substitution character
   */
      int
  syn_get_sub_char(void)
  {
      return current_sub_char;
  }
  #endif
  
  #if defined(FEAT_EVAL) || defined(PROTO)
  /*
   * Return the syntax ID at position "i" in the current stack.
   * The caller must have called syn_get_id() before to fill the stack.
   * Returns -1 when "i" is out of range.
   */
      int
  syn_get_stack_item(int i)
  {
      if (i >= current_state.ga_len)
      {
  	// Need to invalidate the state, because we didn't properly finish it
  	// for the last character, "keep_state" was TRUE.
  	invalidate_current_state();
  	current_col = MAXCOL;
  	return -1;
      }
      return CUR_STATE(i).si_id;
  }
  #endif
  
  #if defined(FEAT_FOLDING) || defined(PROTO)
  /*
   * Function called to get folding level for line "lnum" in window "wp".
   */
      int
  syn_get_foldlevel(win_T *wp, long lnum)
  {
      int		level = 0;
      int		i;
  
      // Return quickly when there are no fold items at all.
      if (wp->w_s->b_syn_folditems != 0
  	    && !wp->w_s->b_syn_error
  # ifdef SYN_TIME_LIMIT
  	    && !wp->w_s->b_syn_slow
  # endif
  	    )
      {
  	syntax_start(wp, lnum);
  
  	for (i = 0; i < current_state.ga_len; ++i)
  	    if (CUR_STATE(i).si_flags & HL_FOLD)
  		++level;
      }
      if (level > wp->w_p_fdn)
      {
  	level = wp->w_p_fdn;
  	if (level < 0)
  	    level = 0;
      }
      return level;
  }
  #endif
  
  #if defined(FEAT_PROFILE) || defined(PROTO)
  /*
   * ":syntime".
   */
      void
  ex_syntime(exarg_T *eap)
  {
      if (STRCMP(eap->arg, "on") == 0)
  	syn_time_on = TRUE;
      else if (STRCMP(eap->arg, "off") == 0)
  	syn_time_on = FALSE;
      else if (STRCMP(eap->arg, "clear") == 0)
  	syntime_clear();
      else if (STRCMP(eap->arg, "report") == 0)
  	syntime_report();
      else
  	semsg(_(e_invarg2), eap->arg);
  }
  
      static void
  syn_clear_time(syn_time_T *st)
  {
      profile_zero(&st->total);
      profile_zero(&st->slowest);
      st->count = 0;
      st->match = 0;
  }
  
  /*
   * Clear the syntax timing for the current buffer.
   */
      static void
  syntime_clear(void)
  {
      int		idx;
      synpat_T	*spp;
  
      if (!syntax_present(curwin))
      {
  	msg(_(msg_no_items));
  	return;
      }
      for (idx = 0; idx < curwin->w_s->b_syn_patterns.ga_len; ++idx)
      {
  	spp = &(SYN_ITEMS(curwin->w_s)[idx]);
  	syn_clear_time(&spp->sp_time);
      }
  }
  
  /*
   * Function given to ExpandGeneric() to obtain the possible arguments of the
   * ":syntime {on,off,clear,report}" command.
   */
      char_u *
  get_syntime_arg(expand_T *xp UNUSED, int idx)
  {
      switch (idx)
      {
  	case 0: return (char_u *)"on";
  	case 1: return (char_u *)"off";
  	case 2: return (char_u *)"clear";
  	case 3: return (char_u *)"report";
      }
      return NULL;
  }
  
  typedef struct
  {
      proftime_T	total;
      int		count;
      int		match;
      proftime_T	slowest;
      proftime_T	average;
      int		id;
      char_u	*pattern;
  } time_entry_T;
  
      static int
  syn_compare_syntime(const void *v1, const void *v2)
  {
      const time_entry_T	*s1 = v1;
      const time_entry_T	*s2 = v2;
  
      return profile_cmp(&s1->total, &s2->total);
  }
  
  /*
   * Clear the syntax timing for the current buffer.
   */
      static void
  syntime_report(void)
  {
      int		idx;
      synpat_T	*spp;
  # ifdef FEAT_FLOAT
      proftime_T	tm;
  # endif
      int		len;
      proftime_T	total_total;
      int		total_count = 0;
      garray_T    ga;
      time_entry_T *p;
  
      if (!syntax_present(curwin))
      {
  	msg(_(msg_no_items));
  	return;
      }
  
      ga_init2(&ga, sizeof(time_entry_T), 50);
      profile_zero(&total_total);
      for (idx = 0; idx < curwin->w_s->b_syn_patterns.ga_len; ++idx)
      {
  	spp = &(SYN_ITEMS(curwin->w_s)[idx]);
  	if (spp->sp_time.count > 0)
  	{
  	    (void)ga_grow(&ga, 1);
  	    p = ((time_entry_T *)ga.ga_data) + ga.ga_len;
  	    p->total = spp->sp_time.total;
  	    profile_add(&total_total, &spp->sp_time.total);
  	    p->count = spp->sp_time.count;
  	    p->match = spp->sp_time.match;
  	    total_count += spp->sp_time.count;
  	    p->slowest = spp->sp_time.slowest;
  # ifdef FEAT_FLOAT
  	    profile_divide(&spp->sp_time.total, spp->sp_time.count, &tm);
  	    p->average = tm;
  # endif
  	    p->id = spp->sp_syn.id;
  	    p->pattern = spp->sp_pattern;
  	    ++ga.ga_len;
  	}
      }
  
      // Sort on total time. Skip if there are no items to avoid passing NULL
      // pointer to qsort().
      if (ga.ga_len > 1)
  	qsort(ga.ga_data, (size_t)ga.ga_len, sizeof(time_entry_T),
  							 syn_compare_syntime);
  
      msg_puts_title(_("  TOTAL      COUNT  MATCH   SLOWEST     AVERAGE   NAME               PATTERN"));
      msg_puts("\n");
      for (idx = 0; idx < ga.ga_len && !got_int; ++idx)
      {
  	p = ((time_entry_T *)ga.ga_data) + idx;
  
  	msg_puts(profile_msg(&p->total));
  	msg_puts(" "); // make sure there is always a separating space
  	msg_advance(13);
  	msg_outnum(p->count);
  	msg_puts(" ");
  	msg_advance(20);
  	msg_outnum(p->match);
  	msg_puts(" ");
  	msg_advance(26);
  	msg_puts(profile_msg(&p->slowest));
  	msg_puts(" ");
  	msg_advance(38);
  # ifdef FEAT_FLOAT
  	msg_puts(profile_msg(&p->average));
  	msg_puts(" ");
  # endif
  	msg_advance(50);
  	msg_outtrans(highlight_group_name(p->id - 1));
  	msg_puts(" ");
  
  	msg_advance(69);
  	if (Columns < 80)
  	    len = 20; // will wrap anyway
  	else
  	    len = Columns - 70;
  	if (len > (int)STRLEN(p->pattern))
  	    len = (int)STRLEN(p->pattern);
  	msg_outtrans_len(p->pattern, len);
  	msg_puts("\n");
      }
      ga_clear(&ga);
      if (!got_int)
      {
  	msg_puts("\n");
  	msg_puts(profile_msg(&total_total));
  	msg_advance(13);
  	msg_outnum(total_count);
  	msg_puts("\n");
      }
  }
  #endif
  
  #endif // FEAT_SYN_HL
  