(handle_auto_composed_prop): Simplify the code. Never

return HANDLED_RECOMPUTE_PROPS.

diff --git a/src/xdisp.c b/src/xdisp.c
index 8ae136c9f756a3451428e272fdfa64bc94c0a9c9..e120a8fa5a7e2ab85a844df7075a56f2b303e940 100644 (file)
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -4554,50 +4554,87 @@ handle_auto_composed_prop (it)
   if (FUNCTIONP (Vauto_composition_function))
     {
       Lisp_Object val;
-      EMACS_INT pos, this_pos;
+      EMACS_INT pos, pos_byte, this_pos, start, end;
+      int c;
 
       if (STRINGP (it->string))
-       pos = IT_STRING_CHARPOS (*it);
+       {
+         const unsigned char *s;
+
+         pos = IT_STRING_CHARPOS (*it);
+         pos_byte = IT_STRING_BYTEPOS (*it);
+         s = SDATA (it->string) + pos_byte;
+         if (STRING_MULTIBYTE (it->string))
+           c = STRING_CHAR (s, 0);
+         else
+           c = *s;
+       }
       else
-       pos = IT_CHARPOS (*it);
+       {
+         pos = IT_CHARPOS (*it);
+         pos_byte = IT_BYTEPOS (*it);
+         c = FETCH_CHAR (pos_byte);
+       }
       this_pos = pos;
 
-      val =Fget_char_property (make_number (pos), Qauto_composed, it->string);
-      if (! NILP (val))
+      if (get_property_and_range (pos, Qauto_composed, &val, &start, &end,
+                                 it->string))
        {
-         Lisp_Object limit = Qnil, next;
-         
-         /* As Fnext_single_char_property_change is very slow, we
-            limit the search to the current line.  */
-         if (STRINGP (it->string))
-           limit = make_number (SCHARS (it->string));
-         else
-           limit = make_number (find_next_newline_no_quit (pos, 1));
+         Lisp_Object cmp_prop;
+         EMACS_INT cmp_start, cmp_end;
 
-         next = (Fnext_single_property_change
-                 (make_number (pos), Qauto_composed, it->string, limit));
-         if (XINT (next) < XINT (limit))
+#ifdef USE_FONT_BACKEND
+         if (enable_font_backend
+             && get_property_and_range (pos, Qcomposition, &cmp_prop,
+                                        &cmp_start, &cmp_end, it->string)
+             && cmp_start == pos
+             && COMPOSITION_METHOD (cmp_prop) == COMPOSITION_WITH_GLYPH_STRING)
            {
-             /* The current point is auto-composed, but there exist
-                characters not yet composed beyond the auto-composed
-                region.  There's a possiblity that the last
-                characters in the region may be newly composed.  */
-             int charpos = XINT (next) - 1, bytepos, c;
+             Lisp_Object gstring = COMPOSITION_COMPONENTS (cmp_prop);
+             Lisp_Object font_object = LGSTRING_FONT (gstring);
+
+             if (! EQ (font_object,
+                       font_at (c, pos, FACE_FROM_ID (it->f, it->face_id),
+                                it->w, it->string)))
+               /* We must re-compute the composition.  */
+               val = Qnil;
+           }
+#endif
+         if (! NILP (val))
+           {
+             EMACS_INT limit;
 
+             /* As Fnext_single_char_property_change is very slow, we
+                limit the search to the current line.  */
              if (STRINGP (it->string))
-               {
-                 bytepos = string_char_to_byte (it->string, charpos);
-                 c = SDATA (it->string)[bytepos];
-               }
+               limit = SCHARS (it->string);
              else
+               limit = find_next_newline_no_quit (pos, 1);
+
+             if (end < limit)
                {
-                 bytepos = CHAR_TO_BYTE (charpos);
-                 c = FETCH_BYTE (bytepos);
+                 /* The current point is auto-composed, but there
+                    exist characters not yet composed beyond the
+                    auto-composed region.  There's a possiblity that
+                    the last characters in the region may be newly
+                    composed.  */
+                 int charpos = end - 1, bytepos, c;
+
+                 if (STRINGP (it->string))
+                   {
+                     bytepos = string_char_to_byte (it->string, charpos);
+                     c = SDATA (it->string)[bytepos];
+                   }
+                 else
+                   {
+                     bytepos = CHAR_TO_BYTE (charpos);
+                     c = FETCH_BYTE (bytepos);
+                   }
+                 if (c != '\n')
+                   /* If the last character is not newline, it may be
+                      composed with the following characters.  */
+                   val = Qnil, pos = charpos + 1;
                }
-             if (c != '\n')
-               /* If the last character is not newline, it may be
-                  composed with the following characters.  */
-               val = Qnil, pos = charpos + 1;
            }
        }
       if (NILP (val))
@@ -4611,45 +4648,12 @@ handle_auto_composed_prop (it)
          args[2] = it->string;
 #ifdef USE_FONT_BACKEND
          if (enable_font_backend)
-           {
-             struct face *face = FACE_FROM_ID (it->f, it->face_id);
-             int c;
-
-             if (STRINGP (it->string))
-               {
-                 EMACS_INT pos_byte = IT_STRING_BYTEPOS (*it);
-                 const unsigned char *s = SDATA (it->string) + pos_byte;
-
-                 if (STRING_MULTIBYTE (it->string))
-                   it->c = STRING_CHAR (s, 0);
-                 else
-                   it->c = *s;
-               }
-             else
-               {
-                 EMACS_INT pos_byte = IT_BYTEPOS (*it);
-
-                 it->c = FETCH_CHAR (pos_byte);
-               }
-             args[3] = it->window;
-           }
+           args[3] = it->window;
          else
 #endif /* USE_FONT_BACKEND */
            args[3] = Qnil;
          safe_call (4, args);
          unbind_to (count, Qnil);
-
-         if (this_pos == pos)
-           {
-             val = Fget_char_property (args[1], Qauto_composed, it->string);
-             /* Return HANDLED_RECOMPUTE_PROPS only if function composed
-                something.  This avoids an endless loop if they failed to
-                fontify the text for which reason ever.  */
-             if (! NILP (val))
-               handled = HANDLED_RECOMPUTE_PROPS;
-           }
-         else
-           handled = HANDLED_RECOMPUTE_PROPS;
        }
     }