Fix display of 'display' strings in RTL paragraphs at window-start

* src/xdisp.c (handle_single_display_spec)
(get_overlay_strings_1, push_prefix_prop): Initialize bidi
paragraph direction if not yet done.  (Bug#72287)

1 files changed, 22 insertions, 4 deletions

diff --git a/src/xdisp.c b/src/xdisp.c
index 45317cc9f5d..a8f9f59b654 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -6355,6 +6355,12 @@ handle_single_display_spec (struct it *it, Lisp_Object spec, Lisp_Object object,
           return retval;
         }
 
+      /* We want the string to inherit the paragraph direction of the
+         parent object, so we need to calculate that if not yet done.  */
+      ptrdiff_t eob = (BUFFERP (object) ? ZV : it->end_charpos);
+      if (it->bidi_it.first_elt && it->bidi_it.charpos < eob)
+        bidi_paragraph_init (it->paragraph_embedding, &it->bidi_it, true);
+
       /* Save current settings of IT so that we can restore them
          when we are finished with the glyph property value.  */
       push_it (it, position);
@@ -6387,9 +6393,10 @@ handle_single_display_spec (struct it *it, Lisp_Object spec, Lisp_Object object,
           if (BUFFERP (object))
             *position = start_pos;
 
-          /* Force paragraph direction to be that of the parent
-             object.  If the parent object's paragraph direction is
-             not yet determined, default to L2R.  */
+          /* Force paragraph direction to be that of the parent object.
+             If the parent object's paragraph direction is not yet
+             determined (which shouldn not happen, since we called
+             bidi_paragraph_init above), default to L2R.  */
           if (it->bidi_p && it->bidi_it.paragraph_dir == R2L)
             it->paragraph_embedding = it->bidi_it.paragraph_dir;
           else
@@ -7044,6 +7051,11 @@ get_overlay_strings_1 (struct it *it, ptrdiff_t charpos, bool compute_stop_p)
          strings have been processed.  */
       eassert (!compute_stop_p || it->sp == 0);
 
+      /* We want the string to inherit the paragraph direction of the
+         parent object, so we need to calculate that if not yet done.  */
+      if (it->bidi_it.first_elt && it->bidi_it.charpos < ZV)
+        bidi_paragraph_init (it->paragraph_embedding, &it->bidi_it, true);
+
       /* When called from handle_stop, there might be an empty display
          string loaded.  In that case, don't bother saving it.  But
          don't use this optimization with the bidi iterator, since we
@@ -7197,7 +7209,7 @@ iterate_out_of_display_property (struct it *it)
   eassert (eob >= CHARPOS (it->position) && CHARPOS (it->position) >= bob);
 
   /* Maybe initialize paragraph direction.  If we are at the beginning
-     of a new paragraph, next_element_from_buffer may not have a
+     of a new paragraph, next_element_from_buffer may not have had a
      chance to do that.  */
   if (it->bidi_it.first_elt && it->bidi_it.charpos < eob)
     bidi_paragraph_init (it->paragraph_embedding, &it->bidi_it, true);
@@ -24415,6 +24427,12 @@ push_prefix_prop (struct it *it, Lisp_Object prop)
            || it->method == GET_FROM_STRING
            || it->method == GET_FROM_IMAGE);
 
+  /* We want the string to inherit the paragraph direction of the parent
+     object, so we need to calculate that if not yet done.  */
+  ptrdiff_t eob = (STRINGP (it->string) ? SCHARS (it->string) : ZV);
+  if (it->bidi_it.first_elt && it->bidi_it.charpos < eob)
+    bidi_paragraph_init (it->paragraph_embedding, &it->bidi_it, true);
+
   /* We need to save the current buffer/string position, so it will be
      restored by pop_it, because iterate_out_of_display_property
      depends on that being set correctly, but some situations leave