From e98b307036755d7da02a7d7c5723e5032796ca09 Mon Sep 17 00:00:00 2001
From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Fri, 6 Feb 2015 02:33:41 +0000
Subject: [PATCH] variable.c: ignore mortal classid

* variable.c (classname): ignore classid if it is a mortal symbol.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49519 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 variable.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/variable.c b/variable.c
index 1395f5d625..68235ab86d 100644
--- a/variable.c
+++ b/variable.c
@@ -163,8 +163,9 @@ classname(VALUE klass, int *permanent)
 	if (!st_lookup(RCLASS_IV_TBL(klass), (st_data_t)classpath, &n)) {
 	    ID cid = 0;
 	    if (st_lookup(RCLASS_IV_TBL(klass), (st_data_t)classid, &n)) {
-		cid = SYM2ID(n);
-		path = find_class_path(klass, cid);
+		VALUE cname = (VALUE)n;
+		cid = rb_check_id(&cname);
+		if (cid) path = find_class_path(klass, cid);
 	    }
 	    if (NIL_P(path)) {
 		path = find_class_path(klass, (ID)0);