To: vim-dev@vim.org
Subject: Patch 6.2.219
Fcc: outbox
From: Bram Moolenaar <Bram@moolenaar.net>
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------------

Patch 6.2.219
Problem:    Syntax highlighting hangs on an empty match of an item with a
	    nextgroup.  (Charles Campbell)
Solution:   Remember that the item has already matched and don't match it
	    again at the same position.
Files:	    src/syntax.c


*** ../vim-6.2.218/src/syntax.c	Sat Sep 27 19:26:33 2003
--- src/syntax.c	Thu Jan 29 21:14:40 2004
***************
*** 348,354 ****
  static void validate_current_state __ARGS((void));
  static int syn_finish_line __ARGS((int syncing));
  static int syn_current_attr __ARGS((int syncing, int displaying));
! static int did_match_already __ARGS((int idx));
  static stateitem_T *push_next_match __ARGS((stateitem_T *cur_si));
  static void check_state_ends __ARGS((void));
  static void update_si_attr __ARGS((int idx));
--- 348,354 ----
  static void validate_current_state __ARGS((void));
  static int syn_finish_line __ARGS((int syncing));
  static int syn_current_attr __ARGS((int syncing, int displaying));
! static int did_match_already __ARGS((int idx, garray_T *gap));
  static stateitem_T *push_next_match __ARGS((stateitem_T *cur_si));
  static void check_state_ends __ARGS((void));
  static void update_si_attr __ARGS((int idx));
***************
*** 1730,1737 ****
--- 1730,1740 ----
      reg_extmatch_T *cur_extmatch = NULL;
      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?
***************
*** 1775,1780 ****
--- 1778,1787 ----
  		    && (syn_buf->b_keywtab != NULL
  			    || syn_buf->b_keywtab_ic != NULL);
  
+     /* 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, sizeof(int), 10);
+ 
      /*
       * Repeat matching keywords and patterns, to find contained items at the
       * same column.  This stops when there are no extra matches at the current
***************
*** 1951,1957 ****
  			     * before, skip it.  Must retry in the next
  			     * column, because it may match from there.
  			     */
! 			    if (did_match_already(idx))
  			    {
  				try_next_column = TRUE;
  				continue;
--- 1958,1964 ----
  			     * 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;
***************
*** 2070,2075 ****
--- 2077,2092 ----
  			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;
+ 			    --zero_width_next_ga.ga_room;
+ 			}
  			next_match_idx = -1;
  		    }
  		    else
***************
*** 2172,2177 ****
--- 2189,2197 ----
  	    && !(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;
***************
*** 2185,2202 ****
   * Check if we already matched pattern "idx" at the current column.
   */
      static int
! did_match_already(idx)
!     int	    idx;
  {
      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;
!     }
      return FALSE;
  }
  
--- 2205,2228 ----
   * Check if we already matched pattern "idx" at the current column.
   */
      static int
! did_match_already(idx, gap)
!     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;
  }
  
*** ../vim-6.2.218/src/version.c	Sun Feb  1 19:59:21 2004
--- src/version.c	Sun Feb  1 20:00:45 2004
***************
*** 639,640 ****
--- 639,642 ----
  {   /* Add new patch number below this line */
+ /**/
+     219,
  /**/

-- 
The Feynman problem solving Algorithm:
	1) Write down the problem
	2) Think real hard
	3) Write down the answer

 /// Bram Moolenaar -- Bram@Moolenaar.net -- http://www.Moolenaar.net   \\\
///        Sponsor Vim, vote for features -- http://www.Vim.org/sponsor/ \\\
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