fix pointer thing

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@8891 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/switch_xml.cpp

@@ -1545,7 +1545,9 @@ static char *switch_xml_ampencode(const char *s, switch_size_t len, char **dst,
 {
 	const char *e = NULL;
 	int immune = 0;
-	
+
+	if (!s && *s) return *dst;	
+
 	if (len) {
 		e = s + len;
 	}