Fixes: debbugs:11141

* w32menu.c (is_simple_dialog): Properly check lisp types.

src/ChangeLog

+2012-04-01  Andreas Schwab  <schwab@linux-m68k.org>
+
+	* w32menu.c (is_simple_dialog): Properly check lisp types.
+	(Bug#11141)
+
 2012-03-31  Eli Zaretskii  <eliz@gnu.org>
 
 	* xdisp.c (move_it_by_lines): When DVPOS is positive, and the

src/w32menu.c

@@ -1173,18 +1173,23 @@ w32_dialog_show (FRAME_PTR f, int keymaps,
 static int
 is_simple_dialog (Lisp_Object contents)
 {
-  Lisp_Object options = XCDR (contents);
+  Lisp_Object options;
   Lisp_Object name, yes, no, other;
 
+  if (!CONSP (contents))
+    return 0;
+  options = XCDR (contents);
+
   yes = build_string ("Yes");
   no = build_string ("No");
 
   if (!CONSP (options))
     return 0;
 
-  name = XCAR (XCAR (options));
-  if (!CONSP (options))
+  name = XCAR (options);
+  if (!CONSP (name))
     return 0;
+  name = XCAR (name);
 
   if (!NILP (Fstring_equal (name, yes)))
     other = no;
@@ -1197,7 +1202,10 @@ is_simple_dialog (Lisp_Object contents)
   if (!CONSP (options))
     return 0;
 
-  name = XCAR (XCAR (options));
+  name = XCAR (options);
+  if (!CONSP (name))
+    return 0;
+  name = XCAR (name);
   if (NILP (Fstring_equal (name, other)))
     return 0;