From 17cd5ac4af3b8aaec568e41e5531af65cd1adf45 Mon Sep 17 00:00:00 2001
From: ko1 <ko1@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Tue, 18 Jun 2013 02:17:59 +0000
Subject: [PATCH] * gc.c (gc_mark_maybe): check to skip T_NONE. * gc.c
 (markable_object_p): do not need to check (flags == 0) here.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41372 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog |  6 ++++++
 gc.c      | 22 ++++++++++++++--------
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index dbd9135bbe..dedac846a8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Tue Jun 18 11:02:18 2013  Koichi Sasada  <ko1@atdot.net>
+
+	* gc.c (gc_mark_maybe): check to skip T_NONE.
+
+	* gc.c (markable_object_p): do not need to check (flags == 0) here.
+
 Tue Jun 18 10:17:37 2013  Koichi Sasada  <ko1@atdot.net>
 
 	* variable.c (rb_autoload): fix WB miss.
diff --git a/gc.c b/gc.c
index 530a232fd6..2f0d25b132 100644
--- a/gc.c
+++ b/gc.c
@@ -2916,9 +2916,11 @@ static void
 gc_mark_maybe(rb_objspace_t *objspace, VALUE obj)
 {
     (void)VALGRIND_MAKE_MEM_DEFINED(&obj, sizeof(obj));
-    if (is_pointer_to_heap(objspace, (void *)obj) &&
-	BUILTIN_TYPE(obj) != T_ZOMBIE) {
-	gc_mark(objspace, obj);
+    if (is_pointer_to_heap(objspace, (void *)obj)) {
+	int type = BUILTIN_TYPE(obj);
+	if (type != T_ZOMBIE && type != T_NONE) {
+	    gc_mark(objspace, obj);
+	}
     }
 }
 
@@ -2948,17 +2950,21 @@ gc_mark_ptr(rb_objspace_t *objspace, VALUE ptr)
 static int
 markable_object_p(rb_objspace_t *objspace, VALUE obj)
 {
-    if (rb_special_const_p(obj)) return 0; /* special const not marked */
-    if (RBASIC(obj)->flags == 0) return 0; /* free cell */
-    if (RGENGC_CHECK_MODE && BUILTIN_TYPE(obj) == T_ZOMBIE)
-      rb_bug("markable_object_p: %p is T_ZOMBIE", (void *)obj);
+    if (rb_special_const_p(obj)) return 0; /* special const is not markable */
+
+    if (RGENGC_CHECK_MODE) {
+	if (!is_pointer_to_heap(objspace, (void *)obj)) rb_bug("markable_object_p: %p is not pointer to heap", (void *)obj);
+	if (BUILTIN_TYPE(obj) == T_NONE)   rb_bug("markable_object_p: %p is T_NONE", (void *)obj);
+	if (BUILTIN_TYPE(obj) == T_ZOMBIE) rb_bug("markable_object_p: %p is T_ZOMBIE", (void *)obj);
+    }
+
     return 1;
 }
 
 int
 rb_objspace_markable_object_p(VALUE obj)
 {
-    return markable_object_p(/* now it doesn't use &rb_objspace */ 0, obj);
+    return markable_object_p(&rb_objspace, obj);
 }
 
 static const char *