(note_mouse_highlight): If an overlapping overlay

exists, but we find that we highlight the same overlay as before,
don't do the highlighting again.

2 files changed, 20 insertions, 5 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 3c851d1c7f6..26ee254877a 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,9 @@
+2001-05-30  Gerd Moellmann  <gerd@gnu.org>
+
+        * xterm.c (note_mouse_highlight): If an overlapping overlay
+        exists, but we find that we highlight the same overlay as before,
+        don't do the highlighting again.
+
 2001-05-29  Gerd Moellmann  <gerd@gnu.org>
 
         * xmenu.c (single_submenu, xmenu_show) [!HAVE_MULTILINGUAL_MENU]:
diff --git a/src/xterm.c b/src/xterm.c
index 394b75cfe6c..f6f3f599798 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -6959,10 +6959,6 @@ note_mouse_highlight (f, x, y)
           || (OVERLAYP (dpyinfo->mouse_face_overlay)
               && mouse_face_overlay_overlaps (dpyinfo->mouse_face_overlay)))
         {
-          /* Clear the display of the old active region, if any.  */
-          if (clear_mouse_face (dpyinfo))
-            cursor = None;
-
           /* Find the highest priority overlay that has a mouse-face
              property.  */
           overlay = Qnil;
@@ -6972,8 +6968,19 @@ note_mouse_highlight (f, x, y)
               if (!NILP (mouse_face))
                 overlay = overlay_vec[i];
             }
-          dpyinfo->mouse_face_overlay = overlay;
+          
+          /* If we're actually highlighting the same overlay as
+             before, there's no need to do that again.  */
+          if (!NILP (overlay)
+              && EQ (overlay, dpyinfo->mouse_face_overlay))
+            goto check_help_echo;
             
+          dpyinfo->mouse_face_overlay = overlay;
+
+          /* Clear the display of the old active region, if any.  */
+          if (clear_mouse_face (dpyinfo))
+            cursor = None;
+
           /* If no overlay applies, get a text property.  */
           if (NILP (overlay))
             mouse_face = Fget_text_property (position, Qmouse_face, object);
@@ -7085,6 +7092,8 @@ note_mouse_highlight (f, x, y)
             }
         }
 
+    check_help_echo:
+
       /* Look for a `help-echo' property.  */
       {
         Lisp_Object help, overlay;