Don't core dump if VCL tries to compare NULL pointers, just let the

comparison fail.  This typically happens if a paticular header is
not present.


git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@1971 d4fa192b-c00b-0410-8231-f00ffab90ce4

bin/varnishd/cache_vrt.c

@@ -508,6 +508,8 @@ VRT_purge(const char *regexp, int hash)
 int
 VRT_strcmp(const char *s1, const char *s2)
 {
+	if (s1 == NULL || s2 == NULL)
+		return(1);
 	return (strcmp(s1, s2));
 }