Update redisplay ticks for more operations, and misc modifications

* src/xdisp.c (update_redisplay_ticks): Don't disable redisplay of
mini-windows.
* src/regex-emacs.c (re_match_2_internal):
* src/bidi.c (bidi_find_bracket_pairs, bidi_fetch_char)
(bidi_paragraph_init, bidi_find_other_level_edge): Update the
redisplay tick count as appropriate, when moving the iterator by
one character position actually requires to examine many more
positions.

* doc/emacs/trouble.texi (Long Lines):
* src/xdisp.c (syms_of_xdisp) <max_redisplay_ticks>: Update
recommended non-zero values.

4 files changed, 87 insertions, 9 deletions

diff --git a/src/bidi.c b/src/bidi.c
index 4d2c74b17cd..267b62fb0bc 100644
--- a/src/bidi.c
+++ b/src/bidi.c
@@ -1277,6 +1277,12 @@ bidi_fetch_char (ptrdiff_t charpos, ptrdiff_t bytepos, ptrdiff_t *disp_pos,
       SET_TEXT_POS (pos, charpos, bytepos);
       *disp_pos = compute_display_string_pos (&pos, string, w, frame_window_p,
 					      disp_prop);
+      /* The factor of 100 below is a heuristic that needs to be
+	 tuned.  It means we consider 100 buffer positions examined by
+	 the above call roughly equivalent to the display engine
+	 iterating over a single buffer position.  */
+      if (*disp_pos > charpos)
+	update_redisplay_ticks ((*disp_pos - charpos) / 100 + 1, w);
     }
 
   /* Fetch the character at BYTEPOS.  */
@@ -1385,6 +1391,8 @@ bidi_fetch_char (ptrdiff_t charpos, ptrdiff_t bytepos, ptrdiff_t *disp_pos,
       SET_TEXT_POS (pos, charpos + *nchars, bytepos + *ch_len);
       *disp_pos = compute_display_string_pos (&pos, string, w, frame_window_p,
 					      disp_prop);
+      if (*disp_pos > charpos + *nchars)
+	update_redisplay_ticks ((*disp_pos - charpos - *nchars) / 100 + 1, w);
     }
 
   return ch;
@@ -1583,6 +1591,9 @@ bidi_find_paragraph_start (ptrdiff_t pos, ptrdiff_t pos_byte)
   return pos_byte;
 }
 
+/* This tracks how far we needed to search for first strong character.  */
+static ptrdiff_t nsearch_for_strong;
+
 /* On a 3.4 GHz machine, searching forward for a strong directional
    character in a long paragraph full of weaks or neutrals takes about
    1 ms for each 20K characters.  The number below limits each call to
@@ -1652,6 +1663,8 @@ find_first_strong_char (ptrdiff_t pos, ptrdiff_t bytepos, ptrdiff_t end,
       pos += *nchars;
       bytepos += *ch_len;
     }
+
+  nsearch_for_strong += pos - pos1;
   return type;
 }
 
@@ -1681,6 +1694,9 @@ bidi_paragraph_init (bidi_dir_t dir, struct bidi_it *bidi_it, bool no_default_p)
      calls to BYTE_TO_CHAR and its ilk.  */
   ptrdiff_t begbyte = string_p ? 0 : BEGV_BYTE;
   ptrdiff_t end = string_p ? bidi_it->string.schars : ZV;
+  ptrdiff_t pos = bidi_it->charpos;
+
+  nsearch_for_strong = 0;
 
   /* Special case for an empty buffer. */
   if (bytepos == begbyte && bidi_it->charpos == end)
@@ -1702,7 +1718,7 @@ bidi_paragraph_init (bidi_dir_t dir, struct bidi_it *bidi_it, bool no_default_p)
   else if (dir == NEUTRAL_DIR)	/* P2 */
     {
       ptrdiff_t ch_len, nchars;
-      ptrdiff_t pos, disp_pos = -1;
+      ptrdiff_t disp_pos = -1;
       int disp_prop = 0;
       bidi_type_t type;
       const unsigned char *s;
@@ -1800,6 +1816,14 @@ bidi_paragraph_init (bidi_dir_t dir, struct bidi_it *bidi_it, bool no_default_p)
     bidi_it->level_stack[0].level = 0;
 
   bidi_line_init (bidi_it);
+
+  /* The factor of 50 below is a heuristic that needs to be tuned.  It
+     means we consider 50 buffer positions examined by this function
+     roughly equivalent to the display engine iterating over a single
+     buffer position.  */
+  ptrdiff_t nexamined = bidi_it->charpos - pos + nsearch_for_strong;
+  if (nexamined > 0)
+    update_redisplay_ticks (nexamined / 50, bidi_it->w);
 }
 
 
@@ -2566,6 +2590,7 @@ bidi_find_bracket_pairs (struct bidi_it *bidi_it)
   bidi_bracket_type_t btype;
   bidi_type_t type = bidi_it->type;
   bool retval = false;
+  ptrdiff_t n = 0;
 
   /* When scanning backwards, we don't expect any unresolved bidi
      bracket characters.  */
@@ -2695,6 +2720,7 @@ bidi_find_bracket_pairs (struct bidi_it *bidi_it)
 	    }
 	  old_sidx = bidi_it->stack_idx;
 	  type = bidi_resolve_weak (bidi_it);
+	  n++;
 	  /* Skip level runs excluded from this isolating run sequence.  */
 	  new_sidx = bidi_it->stack_idx;
 	  if (bidi_it->level_stack[new_sidx].level > current_level
@@ -2718,6 +2744,7 @@ bidi_find_bracket_pairs (struct bidi_it *bidi_it)
 		      goto give_up;
 		    }
 		  type = bidi_resolve_weak (bidi_it);
+		  n++;
 		}
 	    }
 	  if (type == NEUTRAL_B
@@ -2794,6 +2821,12 @@ bidi_find_bracket_pairs (struct bidi_it *bidi_it)
     }
 
  give_up:
+  /* The factor of 20 below is a heuristic that needs to be tuned.  It
+     means we consider 20 buffer positions examined by this function
+     roughly equivalent to the display engine iterating over a single
+     buffer position.  */
+  if (n > 0)
+    update_redisplay_ticks (n / 20 + 1, bidi_it->w);
   return retval;
 }
 
@@ -3363,6 +3396,7 @@ bidi_find_other_level_edge (struct bidi_it *bidi_it, int level, bool end_flag)
   else
     {
       int new_level;
+      ptrdiff_t pos0 = bidi_it->charpos;
 
       /* If we are at end of level, its edges must be cached.  */
       if (end_flag)
@@ -3398,6 +3432,12 @@ bidi_find_other_level_edge (struct bidi_it *bidi_it, int level, bool end_flag)
 	    bidi_cache_iterator_state (bidi_it, 1, 1);
 	  }
       } while (new_level >= level);
+      /* The factor of 50 below is a heuristic that needs to be
+	 tuned.  It means we consider 50 buffer positions examined by
+	 the above call roughly equivalent to the display engine
+	 iterating over a single buffer position.  */
+      if (bidi_it->charpos > pos0)
+	update_redisplay_ticks ((bidi_it->charpos - pos0) / 50 + 1, bidi_it->w);
     }
 }
 
diff --git a/src/dispnew.c b/src/dispnew.c
index 9d587ea00e3..4509262ea62 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -2732,18 +2732,23 @@ set_frame_matrix_frame (struct frame *f)
    operations in window matrices of frame_matrix_frame.  */
 
 static void
-make_current (struct glyph_matrix *desired_matrix, struct glyph_matrix *current_matrix, int row)
+make_current (struct glyph_matrix *desired_matrix,
+	      struct glyph_matrix *current_matrix, int row)
 {
   struct glyph_row *current_row = MATRIX_ROW (current_matrix, row);
   struct glyph_row *desired_row = MATRIX_ROW (desired_matrix, row);
   bool mouse_face_p = current_row->mouse_face_p;
 
   /* If we aborted redisplay of this window, a row in the desired
-     matrix might not have its hash computed.  */
-  if (!(!desired_row->used[0]
-	&& !desired_row->used[1]
-	&& !desired_row->used[2])
-      && !desired_row->hash)
+     matrix might not have its hash computed.  But update_window
+     relies on each row having its correct hash, so do it here if
+     needed.  */
+  if (!desired_row->hash
+      /* A glyph row that is not completely empty is unlikely to have
+	 a zero hash value.  */
+      && !(!desired_row->used[0]
+	   && !desired_row->used[1]
+	   && !desired_row->used[2]))
     desired_row->hash = row_hash (desired_row);
 
   /* Do current_row = desired_row.  This exchanges glyph pointers
diff --git a/src/regex-emacs.c b/src/regex-emacs.c
index 8662fe8d6d0..4d87418eeaf 100644
--- a/src/regex-emacs.c
+++ b/src/regex-emacs.c
@@ -33,6 +33,7 @@
 #include "buffer.h"
 #include "syntax.h"
 #include "category.h"
+#include "dispextern.h"
 
 /* Maximum number of duplicates an interval can allow.  Some systems
    define this in other header files, but we want our value, so remove
@@ -3953,6 +3954,9 @@ re_match_2_internal (struct re_pattern_buffer *bufp,
      and need to test it, it's not garbage.  */
   re_char *match_end = NULL;
 
+  /* This keeps track of how many buffer/string positions we examined.  */
+  ptrdiff_t nchars = 0;
+
 #ifdef DEBUG_COMPILES_ARGUMENTS
   /* Counts the total number of registers pushed.  */
   ptrdiff_t num_regs_pushed = 0;
@@ -4209,6 +4213,12 @@ re_match_2_internal (struct re_pattern_buffer *bufp,
 
 	  unbind_to (count, Qnil);
 	  SAFE_FREE ();
+	  /* The factor of 50 below is a heuristic that needs to be tuned.  It
+	     means we consider 50 buffer positions examined by this function
+	     roughly equivalent to the display engine iterating over a single
+	     buffer position.  */
+	  if (nchars > 0)
+	    update_redisplay_ticks (nchars / 50 + 1, NULL);
 	  return dcnt;
 	}
 
@@ -4261,6 +4271,7 @@ re_match_2_internal (struct re_pattern_buffer *bufp,
 		p += pat_charlen;
 		d += buf_charlen;
 		mcnt -= pat_charlen;
+		nchars++;
 	      }
 	    while (mcnt > 0);
 	  else
@@ -4298,6 +4309,7 @@ re_match_2_internal (struct re_pattern_buffer *bufp,
 		p += pat_charlen;
 		d++;
 		mcnt -= pat_charlen;
+		nchars++;
 	      }
 	    while (mcnt > 0);
 
@@ -4321,6 +4333,7 @@ re_match_2_internal (struct re_pattern_buffer *bufp,
 
 	    DEBUG_PRINT ("  Matched \"%d\".\n", *d);
 	    d += buf_charlen;
+	    nchars++;
 	  }
 	  break;
 
@@ -4373,6 +4386,7 @@ re_match_2_internal (struct re_pattern_buffer *bufp,
 	      goto fail;
 
 	    d += len;
+	    nchars++;
 	  }
 	  break;
 
@@ -4492,6 +4506,7 @@ re_match_2_internal (struct re_pattern_buffer *bufp,
 		    goto fail;
 		  }
 		d += dcnt, d2 += dcnt;
+		nchars++;
 	      }
 	  }
 	  break;
@@ -4773,10 +4788,12 @@ re_match_2_internal (struct re_pattern_buffer *bufp,
                 ptrdiff_t charpos = SYNTAX_TABLE_BYTE_TO_CHAR (offset) - 1;
 		UPDATE_SYNTAX_TABLE (charpos);
 		GET_CHAR_BEFORE_2 (c1, d, string1, end1, string2, end2);
+		nchars++;
 		s1 = SYNTAX (c1);
 		UPDATE_SYNTAX_TABLE_FORWARD (charpos + 1);
 		PREFETCH_NOLIMIT ();
 		GET_CHAR_AFTER (c2, d, dummy);
+		nchars++;
 		s2 = SYNTAX (c2);
 
 		if (/* Case 2: Only one of S1 and S2 is Sword.  */
@@ -4812,6 +4829,7 @@ re_match_2_internal (struct re_pattern_buffer *bufp,
 	      UPDATE_SYNTAX_TABLE (charpos);
 	      PREFETCH ();
 	      GET_CHAR_AFTER (c2, d, dummy);
+	      nchars++;
 	      s2 = SYNTAX (c2);
 
 	      /* Case 2: S2 is not Sword. */
@@ -4822,6 +4840,7 @@ re_match_2_internal (struct re_pattern_buffer *bufp,
 	      if (!AT_STRINGS_BEG (d))
 		{
 		  GET_CHAR_BEFORE_2 (c1, d, string1, end1, string2, end2);
+		  nchars++;
 		  UPDATE_SYNTAX_TABLE_BACKWARD (charpos - 1);
 		  s1 = SYNTAX (c1);
 
@@ -4852,6 +4871,7 @@ re_match_2_internal (struct re_pattern_buffer *bufp,
               ptrdiff_t charpos = SYNTAX_TABLE_BYTE_TO_CHAR (offset) - 1;
 	      UPDATE_SYNTAX_TABLE (charpos);
 	      GET_CHAR_BEFORE_2 (c1, d, string1, end1, string2, end2);
+	      nchars++;
 	      s1 = SYNTAX (c1);
 
 	      /* Case 2: S1 is not Sword.  */
@@ -4863,6 +4883,7 @@ re_match_2_internal (struct re_pattern_buffer *bufp,
 		{
 		  PREFETCH_NOLIMIT ();
 		  GET_CHAR_AFTER (c2, d, dummy);
+		  nchars++;
                   UPDATE_SYNTAX_TABLE_FORWARD (charpos + 1);
 		  s2 = SYNTAX (c2);
 
@@ -4893,6 +4914,7 @@ re_match_2_internal (struct re_pattern_buffer *bufp,
 	      UPDATE_SYNTAX_TABLE (charpos);
 	      PREFETCH ();
 	      c2 = RE_STRING_CHAR (d, target_multibyte);
+	      nchars++;
 	      s2 = SYNTAX (c2);
 
 	      /* Case 2: S2 is neither Sword nor Ssymbol. */
@@ -4903,6 +4925,7 @@ re_match_2_internal (struct re_pattern_buffer *bufp,
 	      if (!AT_STRINGS_BEG (d))
 		{
 		  GET_CHAR_BEFORE_2 (c1, d, string1, end1, string2, end2);
+		  nchars++;
 		  UPDATE_SYNTAX_TABLE_BACKWARD (charpos - 1);
 		  s1 = SYNTAX (c1);
 
@@ -4931,6 +4954,7 @@ re_match_2_internal (struct re_pattern_buffer *bufp,
               ptrdiff_t charpos = SYNTAX_TABLE_BYTE_TO_CHAR (offset) - 1;
 	      UPDATE_SYNTAX_TABLE (charpos);
 	      GET_CHAR_BEFORE_2 (c1, d, string1, end1, string2, end2);
+	      nchars++;
 	      s1 = SYNTAX (c1);
 
 	      /* Case 2: S1 is neither Ssymbol nor Sword.  */
@@ -4942,6 +4966,7 @@ re_match_2_internal (struct re_pattern_buffer *bufp,
 		{
 		  PREFETCH_NOLIMIT ();
 		  c2 = RE_STRING_CHAR (d, target_multibyte);
+		  nchars++;
 		  UPDATE_SYNTAX_TABLE_FORWARD (charpos + 1);
 		  s2 = SYNTAX (c2);
 
@@ -4973,6 +4998,7 @@ re_match_2_internal (struct re_pattern_buffer *bufp,
 	      if ((SYNTAX (c) != (enum syntaxcode) mcnt) ^ not)
 		goto fail;
 	      d += len;
+	      nchars++;
 	    }
 	  }
 	  break;
@@ -4999,6 +5025,7 @@ re_match_2_internal (struct re_pattern_buffer *bufp,
 	      if ((!CHAR_HAS_CATEGORY (c, mcnt)) ^ not)
 		goto fail;
 	      d += len;
+	      nchars++;
 	    }
 	  }
 	  break;
@@ -5060,6 +5087,9 @@ re_match_2_internal (struct re_pattern_buffer *bufp,
   unbind_to (count, Qnil);
   SAFE_FREE ();
 
+  if (nchars > 0)
+    update_redisplay_ticks (nchars / 50 + 1, NULL);
+
   return -1;				/* Failure to match.  */
 }
 
diff --git a/src/xdisp.c b/src/xdisp.c
index 1d52bbc6c93..f95aeb6149a 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -17218,7 +17218,10 @@ update_redisplay_ticks (int ticks, struct window *w)
     }
   /* Some callers can be run in contexts unrelated to display code, so
      don't abort them and don't update the tick count in those cases.  */
-  if (!w && !redisplaying_p && !display_working_on_window_p)
+  if ((!w && !redisplaying_p && !display_working_on_window_p)
+      /* We never disable redisplay of a mini-window, since that is
+	 absolutely essential for communicating with Emacs.  */
+      || (w && MINI_WINDOW_P (w)))
     return;
 
   if (ticks > 0)
@@ -36765,7 +36768,7 @@ You can also decide to kill the buffer and visit it in some
 other way, like under `so-long-mode' or literally.
 
 The default value is zero, which disables this feature.
-The recommended non-zero value is between 50000 and 200000,
+The recommended non-zero value is between 100000 and 1000000,
 depending on your patience and the speed of your system.  */);
   max_redisplay_ticks = 0;
 }