[Emacs-diffs] /srv/bzr/emacs/trunk r100033: Fix crash with bidi display on the last empty line (bug#6030).

[Eli Zaretskii]

------------------------------------------------------------
revno: 100033 [merge]
committer: Eli Zaretskii <address@hidden>
branch nick: trunk
timestamp: Sun 2010-04-25 20:06:41 +0300
message:
  Fix crash with bidi display on the last empty line (bug#6030).
  
   xdisp.c (display_line): Don't assume 2nd call to
   get_next_display_element cannot return zero.  (Bug#6030)
  
  Move code that bidi-iterates out of display property to a separate function. 
  
   xdisp.c (iterate_out_of_display_property): New function, body from pop_it.
   (pop_it): Use it.
modified:
  src/ChangeLog
  src/xdisp.c

=== modified file 'src/ChangeLog'
--- a/src/ChangeLog     2010-04-24 19:50:03 +0000
+++ b/src/ChangeLog     2010-04-25 17:06:41 +0000
@@ -1,3 +1,10 @@
+2010-04-25  Eli Zaretskii  <address@hidden>
+
+       * xdisp.c (display_line): Don't assume 2nd call to
+       get_next_display_element cannot return zero.  (Bug#6030)
+       (iterate_out_of_display_property): New function, body from pop_it.
+       (pop_it): Use it.
+
 2010-04-24  Glenn Morris  <address@hidden>
 
        * m/amdx86-64.h (START_FILES, LIB_STANDARD) [__OpenBSD__]:

=== modified file 'src/xdisp.c'
--- a/src/xdisp.c       2010-04-24 11:11:40 +0000
+++ b/src/xdisp.c       2010-04-25 17:06:41 +0000
@@ -5259,6 +5259,33 @@
   ++it->sp;
 }
 
+static void
+iterate_out_of_display_property (it)
+     struct it *it;
+{
+  /* Maybe initialize paragraph direction.  If we are at the beginning
+     of a new paragraph, next_element_from_buffer may not have a
+     chance to do that.  */
+  if (it->bidi_it.first_elt && it->bidi_it.charpos < ZV)
+    bidi_paragraph_init (it->paragraph_embedding, &it->bidi_it);
+  /* prev_stop can be zero, so check against BEGV as well.  */
+  while (it->bidi_it.charpos >= BEGV
+        && it->prev_stop <= it->bidi_it.charpos
+        && it->bidi_it.charpos < CHARPOS (it->position))
+    bidi_get_next_char_visually (&it->bidi_it);
+  /* Record the stop_pos we just crossed, for when we cross it
+     back, maybe.  */
+  if (it->bidi_it.charpos > CHARPOS (it->position))
+    it->prev_stop = CHARPOS (it->position);
+  /* If we ended up not where pop_it put us, resync IT's
+     positional members with the bidi iterator. */
+  if (it->bidi_it.charpos != CHARPOS (it->position))
+    {
+      SET_TEXT_POS (it->position,
+                   it->bidi_it.charpos, it->bidi_it.bytepos);
+      it->current.pos = it->position;
+    }
+}
 
 /* Restore IT's settings from IT->stack.  Called, for example, when no
    more overlay strings must be processed, and we return to delivering
@@ -5309,25 +5336,7 @@
             determine the paragraph base direction if the overlay we
             just processed is at the beginning of a new
             paragraph.  */
-         if (it->bidi_it.first_elt && it->bidi_it.charpos < ZV)
-           bidi_paragraph_init (it->paragraph_embedding, &it->bidi_it);
-         /* prev_stop can be zero, so check against BEGV as well.  */
-         while (it->bidi_it.charpos >= BEGV
-                && it->prev_stop <= it->bidi_it.charpos
-                && it->bidi_it.charpos < CHARPOS (it->position))
-           bidi_get_next_char_visually (&it->bidi_it);
-         /* Record the stop_pos we just crossed, for when we cross it
-            back, maybe.  */
-         if (it->bidi_it.charpos > CHARPOS (it->position))
-           it->prev_stop = CHARPOS (it->position);
-         /* If we ended up not where pop_it put us, resync IT's
-            positional members with the bidi iterator. */
-         if (it->bidi_it.charpos != CHARPOS (it->position))
-           {
-             SET_TEXT_POS (it->position,
-                           it->bidi_it.charpos, it->bidi_it.bytepos);
-             it->current.pos = it->position;
-           }
+         iterate_out_of_display_property (it);
        }
       break;
     case GET_FROM_STRING:
@@ -17979,9 +17988,8 @@
          row_end = it->current;
          /* If the character at max_pos+1 is a newline, skip that as
             well.  Note that this may skip some invisible text.  */
-         if (!get_next_display_element (it))
-           abort ();
-         if (ITERATOR_AT_END_OF_LINE_P (it))
+         if (get_next_display_element (it)
+             && ITERATOR_AT_END_OF_LINE_P (it))
            {
              set_iterator_to_next (it, 1);
              /* Record the position after the newline of a continued