(try_window_id) [!GLYPH_DEBUG]: Give up if

[gnu-emacs] / src / xdisp.c

diff --git a/src/xdisp.c b/src/xdisp.c
index a3ac927f785ddb5711549eb6e1ef34abbd354d18..df8720ee0e8d0da05106704dc8edf255bb73878b 100644 (file)
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -11491,8 +11491,23 @@ try_window_id (w)
   stop_pos = 0;
   if (first_unchanged_at_end_row)
     {
+#if GLYPH_DEBUG
       xassert (last_unchanged_at_beg_row == NULL
               || first_unchanged_at_end_row >= last_unchanged_at_beg_row);
+#else
+      /* This is for the release of 21.1 only, and should be removed
+        after the release.
+
+        This case means that unchanged information is probably bogus,
+        which leads to being unable to compute a correct
+        first_unchanged_at_end_row.  At least that was the case in
+        one debugging session.  I've fixed a bug that can lead to
+        wrong unchanged info, but didn't find a way to reproduce this
+        case.  2001-09-18 gerd.  */
+      if (last_unchanged_at_beg_row 
+         && first_unchanged_at_end_row < last_unchanged_at_beg_row)
+       GIVE_UP (20);
+#endif
       
       /* If this is a continuation line, move forward to the next one
         that isn't.  Changes in lines above affect this line.