(face_at_buffer_position_no_overlays): New function.

src/xfaces.c

@@ -7706,6 +7706,82 @@ face_at_buffer_position (w, pos, region_beg, region_end,
   return lookup_face (f, attrs, 0, NULL);
 }
 
+/* Return the face ID associated with buffer position POS for
+   displaying ASCII characters, but without overlays.
+   Like face_at_buffer_position except it ignores overlays.  */
+
+int
+face_at_buffer_position_no_overlays (w, pos, region_beg, region_end,
+				     endptr, limit, mouse)
+     struct window *w;
+     int pos;
+     int region_beg, region_end;
+     int *endptr;
+     int limit;
+     int mouse;
+{
+  struct frame *f = XFRAME (w->frame);
+  Lisp_Object attrs[LFACE_VECTOR_SIZE];
+  Lisp_Object prop, position;
+  int i, noverlays;
+  Lisp_Object *overlay_vec;
+  Lisp_Object frame;
+  int endpos;
+  Lisp_Object propname = mouse ? Qmouse_face : Qface;
+  Lisp_Object limit1, end;
+  struct face *default_face;
+
+  /* W must display the current buffer.  We could write this function
+     to use the frame and buffer of W, but right now it doesn't.  */
+  /* xassert (XBUFFER (w->buffer) == current_buffer); */
+
+  XSETFRAME (frame, f);
+  XSETFASTINT (position, pos);
+
+  endpos = ZV;
+  if (pos < region_beg && region_beg < endpos)
+    endpos = region_beg;
+
+  /* Get the `face' or `mouse_face' text property at POS, and
+     determine the next position at which the property changes.  */
+  prop = Fget_text_property (position, propname, w->buffer);
+  XSETFASTINT (limit1, (limit < endpos ? limit : endpos));
+  end = Fnext_single_property_change (position, propname, w->buffer, limit1);
+  if (INTEGERP (end))
+    endpos = XINT (end);
+
+  *endptr = endpos;
+
+  default_face = FACE_FROM_ID (f, DEFAULT_FACE_ID);
+
+  /* Optimize common cases where we can use the default face.  */
+  if (NILP (prop)
+      && !(pos >= region_beg && pos < region_end))
+    return DEFAULT_FACE_ID;
+
+  /* Begin with attributes from the default face.  */
+  bcopy (default_face->lface, attrs, sizeof attrs);
+
+  /* Merge in attributes specified via text properties.  */
+  if (!NILP (prop))
+    merge_face_ref (f, prop, attrs, 1, 0);
+
+  /* If in the region, merge in the region face.  */
+  if (pos >= region_beg && pos < region_end)
+    {
+      merge_named_face (f, Qregion, attrs, 0);
+
+      if (region_end < endpos)
+	endpos = region_end;
+    }
+
+  *endptr = endpos;
+
+  /* Look up a realized face with the given face attributes,
+     or realize a new one for ASCII characters.  */
+  return lookup_face (f, attrs, 0, NULL);
+}
+
 
 /* Compute the face at character position POS in Lisp string STRING on
    window W, for ASCII characters.