(IT_update_begin): Don't crash if mouse_face_mouse_frame

member of display_info is NULL.

2 files changed, 9 insertions, 3 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index a019ab9f34b..d471dc885f9 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2000-08-15  Eli Zaretskii  <eliz@is.elta.co.il>
+
+        * msdos.c (IT_update_begin): Don't crash if mouse_face_mouse_frame
+        member of display_info is NULL.
+
 2000-08-15  Gerd Moellmann  <gerd@gnu.org>
 
         * alloc.c (compact_small_strings): Use safe_bcopy, add an
diff --git a/src/msdos.c b/src/msdos.c
index 9387f81ad20..a711f84cf13 100644
--- a/src/msdos.c
+++ b/src/msdos.c
@@ -1913,12 +1913,13 @@ static void
 IT_update_begin (struct frame *f)
 {
   struct display_info *display_info = FRAME_X_DISPLAY_INFO (f);
+  struct frame *mouse_face_frame = display_info->mouse_face_mouse_frame;
   
   highlight = 0;
 
   BLOCK_INPUT;
 
-  if (f == display_info->mouse_face_mouse_frame)
+  if (f && f == mouse_face_frame)
     {
       /* Don't do highlighting for mouse motion during the update.  */
       display_info->mouse_face_defer = 1;
@@ -1955,7 +1956,7 @@ IT_update_begin (struct frame *f)
             clear_mouse_face (display_info);
         }
     }
-  else if (!FRAME_LIVE_P (display_info->mouse_face_mouse_frame))
+  else if (mouse_face_frame && !FRAME_LIVE_P (mouse_face_frame))
     {
       /* If the frame with mouse highlight was deleted, invalidate the
          highlight info.  */
@@ -1986,7 +1987,7 @@ IT_frame_up_to_date (struct frame *f)
   struct window *sw;
 
   if (dpyinfo->mouse_face_deferred_gc
-      || f == dpyinfo->mouse_face_mouse_frame)
+      || (f && f == dpyinfo->mouse_face_mouse_frame))
     {
       BLOCK_INPUT;
       if (dpyinfo->mouse_face_mouse_frame)