(init_from_display_pos): Don't set it->method and

overlay_string_index after pop_it.  Add asserts.
(handle_stop): Look for overlay strings around a display string,
image, or composition.  Handle properties on those strings.
(next_overlay_string): Don't set string, pos or method after pop_it.
(get_overlay_strings_1): Split from get_overlay_strings; don't
modify it if no overlay strings are found.
(get_overlay_strings): Use get_overlay_strings_1.  Always set
it->string and it->method.
(push_it): Push it->image_id and it->method.  Push it->object
instead of it->string if method is GET_FROM_IMAGE.
(pop_it): Pop it->image_id and it->method.  Ppo it->object
instead of it->string if method is GET_FROM_IMAGE.
Reset it->current.string_pos if popped it->string is nil.
(reseat_1): Remove comment dated 19 May 2003.  It expressed doubt
whether a given change was correct; but the change is correct.
Clear it->string_from_display_prop_p.
(set_iterator_to_next): Rely on it->method and it->image_id from
iterator stack, instead of setting them explicitly after pop_it.

1 files changed, 61 insertions, 35 deletions

diff --git a/src/xdisp.c b/src/xdisp.c
index 80237e89fa1..c9bb3092d4c 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -916,6 +916,7 @@ static int display_string P_ ((unsigned char *, Lisp_Object, Lisp_Object,
 static void compute_line_metrics P_ ((struct it *));
 static void run_redisplay_end_trigger_hook P_ ((struct it *));
 static int get_overlay_strings P_ ((struct it *, int));
+static int get_overlay_strings_1 P_ ((struct it *, int, int));
 static void next_overlay_string P_ ((struct it *));
 static void reseat P_ ((struct it *, struct text_pos, int));
 static void reseat_1 P_ ((struct it *, struct text_pos, int));
@@ -2909,8 +2910,8 @@ init_from_display_pos (it, w, pos)
          also ``processed'' overlay strings at ZV.  */
       while (it->sp)
         pop_it (it);
-      it->current.overlay_string_index = -1;
-      it->method = GET_FROM_BUFFER;
+      xassert (it->current.overlay_string_index == -1);
+      xassert (it->method == GET_FROM_BUFFER);
       if (CHARPOS (pos->pos) == ZV)
         it->overlay_strings_at_end_processed_p = 1;
     }
@@ -3021,7 +3022,18 @@ handle_stop (it)
           if (handled == HANDLED_RECOMPUTE_PROPS)
             break;
           else if (handled == HANDLED_RETURN)
-            return;
+            {
+              /* We still want to show before and after strings from
+                 overlays even if the actual buffer text is replaced.  */
+              if (!handle_overlay_change_p || it->sp > 1)
+                return;
+              if (!get_overlay_strings_1 (it, 0, 0))
+                return;
+              it->string_from_display_prop_p = 0;
+              handle_overlay_change_p = 0;
+              handled = HANDLED_RECOMPUTE_PROPS;
+              break;
+            }
           else if (handled == HANDLED_OVERLAY_STRING_CONSUMED)
             handle_overlay_change_p = 0;
         }
@@ -4543,13 +4555,13 @@ next_overlay_string (it)
       int display_ellipsis_p = it->stack[it->sp - 1].display_ellipsis_p;
 
       pop_it (it);
-      xassert (it->stop_charpos >= BEGV
-               && it->stop_charpos <= it->end_charpos);
-      it->string = Qnil;
+      xassert (it->sp > 0
+               || (NILP (it->string)
+                   && it->method == GET_FROM_BUFFER
+                   && it->stop_charpos >= BEGV
+                   && it->stop_charpos <= it->end_charpos));
       it->current.overlay_string_index = -1;
-      SET_TEXT_POS (it->current.string_pos, -1, -1);
       it->n_overlay_strings = 0;
-      it->method = GET_FROM_BUFFER;
 
       /* If we're at the end of the buffer, record that we have
          processed the overlay strings there already, so that
@@ -4805,7 +4817,7 @@ load_overlay_strings (it, charpos)
    least one overlay string was found.  */
 
 static int
-get_overlay_strings (it, charpos)
+get_overlay_strings_1 (it, charpos, compute_stop_p)
      struct it *it;
      int charpos;
 {
@@ -4827,12 +4839,13 @@ get_overlay_strings (it, charpos)
       /* Make sure we know settings in current_buffer, so that we can
          restore meaningful values when we're done with the overlay
          strings.  */
-      compute_stop_pos (it);
+      if (compute_stop_p)
+        compute_stop_pos (it);
       xassert (it->face_id >= 0);
 
       /* Save IT's settings.  They are restored after all overlay
          strings have been processed.  */
-      xassert (it->sp == 0);
+      xassert (!compute_stop_p || it->sp == 0);
       push_it (it);
 
       /* Set up IT to deliver display elements from the first overlay
@@ -4844,13 +4857,22 @@ get_overlay_strings (it, charpos)
       it->end_charpos = SCHARS (it->string);
       it->multibyte_p = STRING_MULTIBYTE (it->string);
       it->method = GET_FROM_STRING;
+      return 1;
     }
-  else
-    {
-      it->string = Qnil;
-      it->current.overlay_string_index = -1;
-      it->method = GET_FROM_BUFFER;
-    }
+
+  it->current.overlay_string_index = -1;
+  return 0;
+}
+
+static int
+get_overlay_strings (it, charpos)
+     struct it *it;
+     int charpos;
+{
+  it->string = Qnil;
+  it->method = GET_FROM_BUFFER;
+
+  (void) get_overlay_strings_1 (it, charpos, 1);
 
   CHECK_IT (it);
 
@@ -4875,13 +4897,18 @@ push_it (it)
 {
   struct iterator_stack_entry *p;
 
-  xassert (it->sp < 2);
+  xassert (it->sp < IT_STACK_SIZE);
   p = it->stack + it->sp;
 
   p->stop_charpos = it->stop_charpos;
   xassert (it->face_id >= 0);
   p->face_id = it->face_id;
-  p->string = it->string;
+  p->image_id = it->image_id;
+  p->method = it->method;
+  if (it->method == GET_FROM_IMAGE)
+    p->string = it->object;
+  else
+    p->string = it->string;
   p->pos = it->current;
   p->end_charpos = it->end_charpos;
   p->string_nchars = it->string_nchars;
@@ -4914,8 +4941,18 @@ pop_it (it)
   p = it->stack + it->sp;
   it->stop_charpos = p->stop_charpos;
   it->face_id = p->face_id;
-  it->string = p->string;
+  it->method = p->method;
+  it->image_id = p->image_id;
   it->current = p->pos;
+  if (it->method == GET_FROM_IMAGE)
+    {
+      it->object = it->string;
+      it->string = Qnil;
+    }
+  else
+    it->string = p->string;
+  if (NILP (it->string))
+    SET_TEXT_POS (it->current.string_pos, -1, -1);
   it->end_charpos = p->end_charpos;
   it->string_nchars = p->string_nchars;
   it->area = p->area;
@@ -5233,15 +5270,10 @@ reseat_1 (it, pos, set_stop_p)
   IT_STRING_BYTEPOS (*it) = -1;
   it->string = Qnil;
   it->method = GET_FROM_BUFFER;
-  /* RMS: I added this to fix a bug in move_it_vertically_backward
-     where it->area continued to relate to the starting point
-     for the backward motion.  Bug report from
-     Nick Roberts <nick@nick.uklinux.net> on 19 May 2003.
-     However, I am not sure whether reseat still does the right thing
-     in general after this change.  */
   it->area = TEXT_AREA;
   it->multibyte_p = !NILP (current_buffer->enable_multibyte_characters);
   it->sp = 0;
+  it->string_from_display_prop_p = 0;
   it->face_before_selective_p = 0;
 
   if (set_stop_p)
@@ -5809,9 +5841,8 @@ set_iterator_to_next (it, reseat_p)
               && it->sp > 0)
             {
               pop_it (it);
-              if (STRINGP (it->string))
+              if (it->method == GET_FROM_STRING)
                 goto consider_string_end;
-              it->method = GET_FROM_BUFFER;
             }
         }
       break;
@@ -5823,13 +5854,8 @@ set_iterator_to_next (it, reseat_p)
          if the `display' property takes up the whole string.  */
       xassert (it->sp > 0);
       pop_it (it);
-      it->image_id = 0;
-      if (STRINGP (it->string))
-        {
-          it->method = GET_FROM_STRING;
-          goto consider_string_end;
-        }
-      it->method = GET_FROM_BUFFER;
+      if (it->method == GET_FROM_STRING)
+        goto consider_string_end;
       break;
 
     default: