Fix bug #9221 with memory leak in bidi display.

Add code to monitor memory allocation for bidi cache shelving.

 src/xdisp.c (display_line): Release buffer allocated for shelved bidi
 cache.
 src/bidi.c (bidi_shelve_cache, bidi_unshelve_cache): Track total
 amount allocated this far in `bidi_cache_total_alloc'.
 (bidi_unshelve_cache): Accept an additional argument JUST_FREE; if
 non-zero, only free the data buffer without restoring the cache
 contents.  All callers changed.
 src/dispextern.h (bidi_unshelve_cache): Update prototype.
 src/xdisp.c (SAVE_IT, pos_visible_p, move_it_in_display_line_to)
 (move_it_in_display_line, move_it_to)
 (move_it_vertically_backward, move_it_by_lines): Replace the call
 to xfree to an equivalent call to bidi_unshelve_cache.
 (move_it_in_display_line_to): Fix logic of returning
 MOVE_POS_MATCH_OR_ZV in the bidi case.

7 files changed, 110 insertions, 63 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 5861ee6c48b..3ac958e0311 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,25 @@
 2011-08-05  Eli Zaretskii  <eliz@gnu.org>
 
+        *xdisp.c (display_line): Release buffer allocated for shelved bidi
+        cache.  (Bug#9221)
+
+        * bidi.c (bidi_shelve_cache, bidi_unshelve_cache): Track total
+        amount allocated this far in `bidi_cache_total_alloc'.
+        (bidi_unshelve_cache): Accept an additional argument JUST_FREE; if
+        non-zero, only free the data buffer without restoring the cache
+        contents.  All callers changed.
+
+        * dispextern.h (bidi_unshelve_cache): Update prototype.
+
+        * xdisp.c (SAVE_IT, pos_visible_p, move_it_in_display_line_to)
+        (move_it_in_display_line, move_it_to)
+        (move_it_vertically_backward, move_it_by_lines): Replace the call
+        to xfree to an equivalent call to bidi_unshelve_cache.
+        (move_it_in_display_line_to): Fix logic of returning
+        MOVE_POS_MATCH_OR_ZV in the bidi case.
+
+2011-08-05  Eli Zaretskii  <eliz@gnu.org>
+
         * xdisp.c (set_cursor_from_row): Prefer the candidate glyph that
         came from a string character with a `cursor' property.  (Bug#9229)
 
diff --git a/src/bidi.c b/src/bidi.c
index ae5143b37e0..00a6aeef954 100644
--- a/src/bidi.c
+++ b/src/bidi.c
@@ -620,12 +620,15 @@ bidi_pop_it (struct bidi_it *bidi_it)
   bidi_cache_last_idx = -1;
 }
 
+ptrdiff_t bidi_cache_total_alloc;
+
 /* Stash away a copy of the cache and its control variables.  */
 void *
 bidi_shelve_cache (void)
 {
   unsigned char *databuf;
 
+  /* Empty cache.  */
   if (bidi_cache_idx == 0)
     return NULL;
 
@@ -634,6 +637,12 @@ bidi_shelve_cache (void)
                      + sizeof (bidi_cache_start_stack)
                      + sizeof (bidi_cache_sp) + sizeof (bidi_cache_start)
                      + sizeof (bidi_cache_last_idx));
+  bidi_cache_total_alloc +=
+    sizeof (bidi_cache_idx) + bidi_cache_idx * sizeof (struct bidi_it)
+    + sizeof (bidi_cache_start_stack)
+    + sizeof (bidi_cache_sp) + sizeof (bidi_cache_start)
+    + sizeof (bidi_cache_last_idx);
+
   memcpy (databuf, &bidi_cache_idx, sizeof (bidi_cache_idx));
   memcpy (databuf + sizeof (bidi_cache_idx),
           bidi_cache, bidi_cache_idx * sizeof (struct bidi_it));
@@ -659,7 +668,7 @@ bidi_shelve_cache (void)
 
 /* Restore the cache state from a copy stashed away by bidi_shelve_cache.  */
 void
-bidi_unshelve_cache (void *databuf)
+bidi_unshelve_cache (void *databuf, int just_free)
 {
   unsigned char *p = databuf;
 
@@ -672,30 +681,47 @@ bidi_unshelve_cache (void *databuf)
     }
   else
     {
-      memcpy (&bidi_cache_idx, p, sizeof (bidi_cache_idx));
-      bidi_cache_ensure_space (bidi_cache_idx);
-      memcpy (bidi_cache, p + sizeof (bidi_cache_idx),
-              bidi_cache_idx * sizeof (struct bidi_it));
-      memcpy (bidi_cache_start_stack,
-              p + sizeof (bidi_cache_idx)
-              + bidi_cache_idx * sizeof (struct bidi_it),
-              sizeof (bidi_cache_start_stack));
-      memcpy (&bidi_cache_sp,
-              p + sizeof (bidi_cache_idx)
-              + bidi_cache_idx * sizeof (struct bidi_it)
-              + sizeof (bidi_cache_start_stack),
-              sizeof (bidi_cache_sp));
-      memcpy (&bidi_cache_start,
-              p + sizeof (bidi_cache_idx)
-              + bidi_cache_idx * sizeof (struct bidi_it)
-              + sizeof (bidi_cache_start_stack) + sizeof (bidi_cache_sp),
-              sizeof (bidi_cache_start));
-      memcpy (&bidi_cache_last_idx,
-              p + sizeof (bidi_cache_idx)
-              + bidi_cache_idx * sizeof (struct bidi_it)
-              + sizeof (bidi_cache_start_stack) + sizeof (bidi_cache_sp)
-              + sizeof (bidi_cache_start),
-              sizeof (bidi_cache_last_idx));
+      if (just_free)
+        {
+          ptrdiff_t idx;
+
+          memcpy (&idx, p, sizeof (bidi_cache_idx));
+          bidi_cache_total_alloc -=
+            sizeof (bidi_cache_idx) + idx * sizeof (struct bidi_it)
+            + sizeof (bidi_cache_start_stack) + sizeof (bidi_cache_sp)
+            + sizeof (bidi_cache_start) + sizeof (bidi_cache_last_idx);
+        }
+      else
+        {
+          memcpy (&bidi_cache_idx, p, sizeof (bidi_cache_idx));
+          bidi_cache_ensure_space (bidi_cache_idx);
+          memcpy (bidi_cache, p + sizeof (bidi_cache_idx),
+                  bidi_cache_idx * sizeof (struct bidi_it));
+          memcpy (bidi_cache_start_stack,
+                  p + sizeof (bidi_cache_idx)
+                  + bidi_cache_idx * sizeof (struct bidi_it),
+                  sizeof (bidi_cache_start_stack));
+          memcpy (&bidi_cache_sp,
+                  p + sizeof (bidi_cache_idx)
+                  + bidi_cache_idx * sizeof (struct bidi_it)
+                  + sizeof (bidi_cache_start_stack),
+                  sizeof (bidi_cache_sp));
+          memcpy (&bidi_cache_start,
+                  p + sizeof (bidi_cache_idx)
+                  + bidi_cache_idx * sizeof (struct bidi_it)
+                  + sizeof (bidi_cache_start_stack) + sizeof (bidi_cache_sp),
+                  sizeof (bidi_cache_start));
+          memcpy (&bidi_cache_last_idx,
+                  p + sizeof (bidi_cache_idx)
+                  + bidi_cache_idx * sizeof (struct bidi_it)
+                  + sizeof (bidi_cache_start_stack) + sizeof (bidi_cache_sp)
+                  + sizeof (bidi_cache_start),
+                  sizeof (bidi_cache_last_idx));
+          bidi_cache_total_alloc -=
+            sizeof (bidi_cache_idx) + bidi_cache_idx * sizeof (struct bidi_it)
+            + sizeof (bidi_cache_start_stack) + sizeof (bidi_cache_sp)
+            + sizeof (bidi_cache_start) + sizeof (bidi_cache_last_idx);
+        }
 
       xfree (p);
     }
diff --git a/src/dispextern.h b/src/dispextern.h
index 2e245479a81..ea4b11baa74 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -2978,7 +2978,7 @@ extern int  bidi_mirror_char (int);
 extern void bidi_push_it (struct bidi_it *);
 extern void bidi_pop_it (struct bidi_it *);
 extern void *bidi_shelve_cache (void);
-extern void bidi_unshelve_cache (void *);
+extern void bidi_unshelve_cache (void *, int);
 
 /* Defined in xdisp.c */
 
diff --git a/src/dispnew.c b/src/dispnew.c
index b2f416701c3..fadfbb26603 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -5282,7 +5282,7 @@ buffer_posn_from_coords (struct window *w, int *x, int *y, struct display_pos *p
      argument is ZV to prevent move_it_in_display_line from matching
      based on buffer positions.  */
   move_it_in_display_line (&it, ZV, to_x, MOVE_TO_X);
-  bidi_unshelve_cache (itdata);
+  bidi_unshelve_cache (itdata, 0);
 
   Fset_buffer (old_current_buffer);
 
diff --git a/src/indent.c b/src/indent.c
index aaeaaf591ef..70689311dd5 100644
--- a/src/indent.c
+++ b/src/indent.c
@@ -2135,7 +2135,7 @@ whether or not it is currently displayed in some window.  */)
         }
 
       SET_PT_BOTH (IT_CHARPOS (it), IT_BYTEPOS (it));
-      bidi_unshelve_cache (itdata);
+      bidi_unshelve_cache (itdata, 0);
     }
 
   if (BUFFERP (old_buffer))
diff --git a/src/window.c b/src/window.c
index 3f5a743f5c6..8df4a857851 100644
--- a/src/window.c
+++ b/src/window.c
@@ -1379,7 +1379,7 @@ if it isn't already recorded.  */)
       if (it.current_y < it.last_visible_y)
         move_it_past_eol (&it);
       value = make_number (IT_CHARPOS (it));
-      bidi_unshelve_cache (itdata);
+      bidi_unshelve_cache (itdata, 0);
 
       if (old_buffer)
         set_buffer_internal (old_buffer);
@@ -4273,7 +4273,7 @@ window_scroll_pixel_based (Lisp_Object window, int n, int whole, int noerror)
         }
 
       start = it.current.pos;
-      bidi_unshelve_cache (itdata);
+      bidi_unshelve_cache (itdata, 0);
     }
   else if (auto_window_vscroll_p)
     {
@@ -4417,7 +4417,7 @@ window_scroll_pixel_based (Lisp_Object window, int n, int whole, int noerror)
             }
           else
             {
-              bidi_unshelve_cache (itdata);
+              bidi_unshelve_cache (itdata, 0);
               if (noerror)
                 return;
               else if (n < 0)   /* could happen with empty buffers */
@@ -4434,7 +4434,7 @@ window_scroll_pixel_based (Lisp_Object window, int n, int whole, int noerror)
             w->vscroll = 0;
           else
             {
-              bidi_unshelve_cache (itdata);
+              bidi_unshelve_cache (itdata, 0);
               if (noerror)
                 return;
               else
@@ -4583,7 +4583,7 @@ window_scroll_pixel_based (Lisp_Object window, int n, int whole, int noerror)
             SET_PT_BOTH (charpos, bytepos);
         }
     }
-  bidi_unshelve_cache (itdata);
+  bidi_unshelve_cache (itdata, 0);
 }
 
 
@@ -5010,7 +5010,7 @@ displayed_window_lines (struct window *w)
   start_display (&it, w, start);
   move_it_vertically (&it, height);
   bottom_y = line_bottom_y (&it);
-  bidi_unshelve_cache (itdata);
+  bidi_unshelve_cache (itdata, 0);
 
   /* rms: On a non-window display,
      the value of it.vpos at the bottom of the screen
@@ -5116,7 +5116,7 @@ and redisplay normally--don't erase and redraw the frame.  */)
           move_it_vertically_backward (&it, window_box_height (w) / 2);
           charpos = IT_CHARPOS (it);
           bytepos = IT_BYTEPOS (it);
-          bidi_unshelve_cache (itdata);
+          bidi_unshelve_cache (itdata, 0);
         }
       else if (iarg < 0)
         {
@@ -5164,7 +5164,7 @@ and redisplay normally--don't erase and redraw the frame.  */)
             }
           if (h <= 0)
             {
-              bidi_unshelve_cache (itdata);
+              bidi_unshelve_cache (itdata, 0);
               return Qnil;
             }
 
@@ -5187,7 +5187,7 @@ and redisplay normally--don't erase and redraw the frame.  */)
           charpos = IT_CHARPOS (it);
           bytepos = IT_BYTEPOS (it);
 
-          bidi_unshelve_cache (itdata);
+          bidi_unshelve_cache (itdata, 0);
         }
       else
         {
diff --git a/src/xdisp.c b/src/xdisp.c
index 59a6bc3f906..69baea95b9c 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -604,7 +604,7 @@ int current_mode_line_height, current_header_line_height;
 #define SAVE_IT(ITCOPY,ITORIG,CACHE)            \
   do {                                          \
     if (CACHE)                                  \
-      xfree (CACHE);                            \
+      bidi_unshelve_cache (CACHE, 1);           \
     ITCOPY = ITORIG;                            \
     CACHE = bidi_shelve_cache();                \
   } while (0)
@@ -613,7 +613,7 @@ int current_mode_line_height, current_header_line_height;
   do {                                          \
     if (pITORIG != pITCOPY)                     \
       *(pITORIG) = *(pITCOPY);                  \
-    bidi_unshelve_cache (CACHE);                \
+    bidi_unshelve_cache (CACHE, 0);             \
     CACHE = NULL;                               \
   } while (0)
 
@@ -1341,9 +1341,9 @@ pos_visible_p (struct window *w, EMACS_INT charpos, int *x, int *y,
           *vpos = it2.vpos;
         }
       else
-        xfree (it2data);
+        bidi_unshelve_cache (it2data, 1);
     }
-  bidi_unshelve_cache (itdata);
+  bidi_unshelve_cache (itdata, 0);
 
   if (old_buffer)
     set_buffer_internal_1 (old_buffer);
@@ -2627,7 +2627,7 @@ init_iterator (struct it *it, struct window *w,
             it->paragraph_embedding = R2L;
           else
             it->paragraph_embedding = NEUTRAL_DIR;
-          bidi_unshelve_cache (NULL);
+          bidi_unshelve_cache (NULL, 0);
           bidi_init_it (charpos, IT_BYTEPOS (*it), FRAME_WINDOW_P (it->f),
                         &it->bidi_it);
         }
@@ -5618,7 +5618,7 @@ back_to_previous_visible_line_start (struct it *it)
         pos = --IT_CHARPOS (it2);
         --IT_BYTEPOS (it2);
         it2.sp = 0;
-        bidi_unshelve_cache (NULL);
+        bidi_unshelve_cache (NULL, 0);
         it2.string_from_display_prop_p = 0;
         it2.from_disp_prop_p = 0;
         if (handle_display_prop (&it2) == HANDLED_RETURN
@@ -5828,7 +5828,7 @@ reseat_1 (struct it *it, struct text_pos pos, int set_stop_p)
     {
       bidi_init_it (IT_CHARPOS (*it), IT_BYTEPOS (*it), FRAME_WINDOW_P (it->f),
                     &it->bidi_it);
-      bidi_unshelve_cache (NULL);
+      bidi_unshelve_cache (NULL, 0);
       it->bidi_it.paragraph_dir = NEUTRAL_DIR;
       it->bidi_it.string.s = NULL;
       it->bidi_it.string.lstring = Qnil;
@@ -8009,13 +8009,13 @@ move_it_in_display_line_to (struct it *it,
              positions smaller than TO_CHARPOS, return
              MOVE_POS_MATCH_OR_ZV, like the unidirectional display
              did.  */
-          if ((op & MOVE_TO_POS) != 0
+          if (it->bidi_p && (op & MOVE_TO_POS) != 0
               && !saw_smaller_pos
               && IT_CHARPOS (*it) > to_charpos)
             {
-              result = MOVE_POS_MATCH_OR_ZV;
-              if (it->bidi_p && IT_CHARPOS (ppos_it) < ZV)
+              if (IT_CHARPOS (ppos_it) < ZV)
                 RESTORE_IT (it, &ppos_it, ppos_data);
+              goto buffer_pos_reached;
             }
           else
             result = MOVE_NEWLINE_OR_CR;
@@ -8054,14 +8054,13 @@ move_it_in_display_line_to (struct it *it,
                      character positions smaller than TO_CHARPOS,
                      return MOVE_POS_MATCH_OR_ZV, like the
                      unidirectional display did.  */
-                  || ((op & MOVE_TO_POS) != 0
+                  || (it->bidi_p && (op & MOVE_TO_POS) != 0
                       && !saw_smaller_pos
                       && IT_CHARPOS (*it) > to_charpos))
                 {
-                  result = MOVE_POS_MATCH_OR_ZV;
-                  if (it->bidi_p && !at_eob_p && IT_CHARPOS (ppos_it) < ZV)
+                  if (!at_eob_p && IT_CHARPOS (ppos_it) < ZV)
                     RESTORE_IT (it, &ppos_it, ppos_data);
-                  break;
+                  goto buffer_pos_reached;
                 }
               if (ITERATOR_AT_END_OF_LINE_P (it))
                 {
@@ -8069,14 +8068,13 @@ move_it_in_display_line_to (struct it *it,
                   break;
                 }
             }
-          else if ((op & MOVE_TO_POS) != 0
+          else if (it->bidi_p && (op & MOVE_TO_POS) != 0
                    && !saw_smaller_pos
                    && IT_CHARPOS (*it) > to_charpos)
             {
-              result = MOVE_POS_MATCH_OR_ZV;
-              if (it->bidi_p && IT_CHARPOS (ppos_it) < ZV)
+              if (IT_CHARPOS (ppos_it) < ZV)
                 RESTORE_IT (it, &ppos_it, ppos_data);
-              break;
+              goto buffer_pos_reached;
             }
           result = MOVE_LINE_TRUNCATED;
           break;
@@ -8096,13 +8094,13 @@ move_it_in_display_line_to (struct it *it,
  done:
 
   if (atpos_data)
-    xfree (atpos_data);
+    bidi_unshelve_cache (atpos_data, 1);
   if (atx_data)
-    xfree (atx_data);
+    bidi_unshelve_cache (atx_data, 1);
   if (wrap_data)
-    xfree (wrap_data);
+    bidi_unshelve_cache (wrap_data, 1);
   if (ppos_data)
-    xfree (ppos_data);
+    bidi_unshelve_cache (ppos_data, 1);
 
   /* Restore the iterator settings altered at the beginning of this
      function.  */
@@ -8137,7 +8135,7 @@ move_it_in_display_line (struct it *it,
             (it, -1, prev_x, MOVE_TO_X);
         }
       else
-        xfree (save_data);
+        bidi_unshelve_cache (save_data, 1);
     }
   else
     move_it_in_display_line_to (it, to_charpos, to_x, op);
@@ -8396,7 +8394,7 @@ move_it_to (struct it *it, EMACS_INT to_charpos, int to_x, int to_y, int to_vpos
     }
 
   if (backup_data)
-    xfree (backup_data);
+    bidi_unshelve_cache (backup_data, 1);
 
   TRACE_MOVE ((stderr, "move_it_to: reached %d\n", reached));
 }
@@ -8475,7 +8473,7 @@ move_it_vertically_backward (struct it *it, int dy)
       RESTORE_IT (it, it, it2data);
       if (nlines > 0)
         move_it_by_lines (it, nlines);
-      xfree (it3data);
+      bidi_unshelve_cache (it3data, 1);
     }
   else
     {
@@ -8671,7 +8669,7 @@ move_it_by_lines (struct it *it, int dvpos)
           if (IT_CHARPOS (*it) >= start_charpos)
             RESTORE_IT (it, &it2, it2data);
           else
-            xfree (it2data);
+            bidi_unshelve_cache (it2data, 1);
         }
       else
         RESTORE_IT (it, it, it2data);
@@ -18779,6 +18777,9 @@ display_line (struct it *it)
         }
     }
 
+  if (wrap_data)
+    bidi_unshelve_cache (wrap_data, 1);
+
   /* If line is not empty and hscrolled, maybe insert truncation glyphs
      at the left window margin.  */
   if (it->first_visible_x