JS_GetClass() can return NULL. Don't dereference the return value without

checking for non-NULL value.

src/sbbs3/js_msgbase.c

@@ -2310,7 +2310,7 @@ js_get_msg_body(JSContext *cx, uintN argc, jsval *arglist)
 			break;
 		} else if(JSVAL_IS_OBJECT(argv[n])) {		/* Use existing header */
 			JSClass *oc=JS_GetClass(cx, JSVAL_TO_OBJECT(argv[n]));
-			if(strcmp(oc->name, js_msghdr_class.name)==0) {
+			if(oc != NULL && strcmp(oc->name, js_msghdr_class.name) == 0) {
 				privatemsg_t	*pmsg=JS_GetPrivate(cx,JSVAL_TO_OBJECT(argv[n]));
 
 				if(pmsg != NULL) {
@@ -2424,7 +2424,7 @@ js_get_msg_tail(JSContext *cx, uintN argc, jsval *arglist)
 			break;
 		} else if(JSVAL_IS_OBJECT(argv[n])) {		/* Use existing header */
 			JSClass *oc=JS_GetClass(cx, JSVAL_TO_OBJECT(argv[n]));
-			if(strcmp(oc->name, js_msghdr_class.name)==0) {
+			if(oc != NULL && strcmp(oc->name, js_msghdr_class.name) == 0) {
 				privatemsg_t	*pmsg=JS_GetPrivate(cx,JSVAL_TO_OBJECT(argv[n]));
 
 				if(pmsg != NULL) {