Patch from Michael Schroeder <Michael.Schroeder@informatik.uni-erlangen.de>

--- ansi.c.orig	Tue Nov 10 16:25:39 1998
+++ ansi.c	Tue Nov 10 16:37:31 1998
@@ -281,6 +281,8 @@
 #endif
 
   fore = D_fore;
+  if (y >= fore->w_height || x2 > fore->w_width)
+    return EXPENSIVE;
   dx = x2 - x1;
   if (doit)
     {
--- mark.c.orig	Tue Nov 10 16:38:12 1998
+++ mark.c	Tue Nov 10 16:38:59 1998
@@ -1240,6 +1240,8 @@
 
   markdata = (struct markdata *)D_lay->l_data;
   fore = D_fore;
+  if (ry >= fore->w_height || xe > fore->w_width)
+    return EXPENSIVE;
   y = D2W(ry);
   ml = WIN(y);
   dx = xe - xs;