Initial version of display/overlay strings is working.

 src/xdisp.c (set_iterator_to_next, get_visually_first_element): Use
 it->bidi_it.string.schars rather than it->string_nchars when
 testing whether we're beyond string end, because string_nchars is
 zero for strings that come from overlays and display properties.
 src/bidi.c (bidi_cache_iterator_state): Fix a bug with testing
 character positions against the cached range, when we use a
 stacked cache.
 src/dispextern.h (struct iterator_stack_entry): New member
 paragraph_embedding.
 src/xdisp.c (push_it, pop_it): Save and restore it.

4 files changed, 23 insertions, 6 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 083aaaaa4bd..8d5275f9702 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,19 @@
 2011-06-25  Eli Zaretskii  <eliz@gnu.org>
 
+        * xdisp.c (set_iterator_to_next, get_visually_first_element): Use
+        it->bidi_it.string.schars rather than it->string_nchars when
+        testing whether we're beyond string end, because string_nchars is
+        zero for strings that come from overlays and display properties.
+
+        * bidi.c (bidi_cache_iterator_state): Fix a bug with testing
+        character positions against the cached range, when we use a
+        stacked cache.
+
+        * xdisp.c (push_it, pop_it): Save and restore it.
+
+        * dispextern.h (struct iterator_stack_entry): New member
+        paragraph_embedding.
+
         * xdisp.c (handle_single_display_spec, next_overlay_string)
         (get_overlay_strings_1, push_display_prop): Set up the bidi
         iterator for displaying display or overlay strings.
diff --git a/src/bidi.c b/src/bidi.c
index b518dd45782..0cd8deb47c0 100644
--- a/src/bidi.c
+++ b/src/bidi.c
@@ -481,7 +481,7 @@ bidi_cache_iterator_state (struct bidi_it *bidi_it, int resolved)
       if (idx > bidi_cache_start &&
           (bidi_it->charpos > (bidi_cache[idx - 1].charpos
                                + bidi_cache[idx - 1].nchars)
-           || bidi_it->charpos < bidi_cache[0].charpos))
+           || bidi_it->charpos < bidi_cache[bidi_cache_start].charpos))
         {
           bidi_cache_reset ();
           idx = bidi_cache_start;
diff --git a/src/dispextern.h b/src/dispextern.h
index d5479c7a64e..16fa3abdd19 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -2251,6 +2251,7 @@ struct it
     Lisp_Object from_overlay;
     enum glyph_row_area area;
     enum it_method method;
+    bidi_dir_t paragraph_embedding;
     unsigned multibyte_p : 1;
     unsigned string_from_display_prop_p : 1;
     unsigned display_ellipsis_p : 1;
diff --git a/src/xdisp.c b/src/xdisp.c
index dc9a62fc0b6..3b934547471 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -5255,6 +5255,7 @@ push_it (struct it *it, struct text_pos *position)
   p->display_ellipsis_p = 0;
   p->line_wrap = it->line_wrap;
   p->bidi_p = it->bidi_p;
+  p->paragraph_embedding = it->paragraph_embedding;
   ++it->sp;
 
   /* Save the state of the bidi iterator as well. */
@@ -5360,6 +5361,7 @@ pop_it (struct it *it)
   it->string_from_display_prop_p = p->string_from_display_prop_p;
   it->line_wrap = p->line_wrap;
   it->bidi_p = p->bidi_p;
+  it->paragraph_embedding = p->paragraph_embedding;
   if (it->bidi_p)
     {
       bidi_pop_it (&it->bidi_it);
@@ -6511,11 +6513,11 @@ set_iterator_to_next (struct it *it, int reseat_p)
     case GET_FROM_C_STRING:
       /* Current display element of IT is from a C string.  */
       if (!it->bidi_p
-          /* If the string position is beyond string_nchars, it means
+          /* If the string position is beyond string's end, it means
              next_element_from_c_string is padding the string with
              blanks, in which case we bypass the bidi iterator,
              because it cannot deal with such virtual characters.  */
-          || IT_CHARPOS (*it) >= it->string_nchars)
+          || IT_CHARPOS (*it) >= it->bidi_it.string.schars)
         {
           IT_BYTEPOS (*it) += it->len;
           IT_CHARPOS (*it) += 1;
@@ -6639,12 +6641,12 @@ set_iterator_to_next (struct it *it, int reseat_p)
       else
         {
           if (!it->bidi_p
-              /* If the string position is beyond string_nchars, it
+              /* If the string position is beyond string's end, it
                  means next_element_from_string is padding the string
                  with blanks, in which case we bypass the bidi
                  iterator, because it cannot deal with such virtual
                  characters.  */
-              || IT_STRING_CHARPOS (*it) >= it->string_nchars)
+              || IT_STRING_CHARPOS (*it) >= it->bidi_it.string.schars)
             {
               IT_STRING_BYTEPOS (*it) += it->len;
               IT_STRING_CHARPOS (*it) += 1;
@@ -6779,7 +6781,7 @@ static void
 get_visually_first_element (struct it *it)
 {
   int string_p = STRINGP (it->string) || it->s;
-  EMACS_INT eob = (string_p ? it->string_nchars : ZV);
+  EMACS_INT eob = (string_p ? it->bidi_it.string.schars : ZV);
   EMACS_INT bob = (string_p ? 0 : BEGV);
 
   if (STRINGP (it->string))