gc.c: mark live objects only

* gc.c (wmap_mark_map): mark live objects only, but delete zombies.
  [ruby-dev:47787] [Bug #9069]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43509 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 4 insertions, 1 deletions

diff --git a/gc.c b/gc.c
index 6bc362b994..1f04ce507c 100644
--- a/gc.c
+++ b/gc.c
@@ -5302,7 +5302,10 @@ struct weakmap {
 static int
 wmap_mark_map(st_data_t key, st_data_t val, st_data_t arg)
 {
-    gc_mark_ptr((rb_objspace_t *)arg, (VALUE)val);
+    rb_objspace_t *objspace = (rb_objspace_t *)arg;
+    VALUE obj = (VALUE)val;
+    if (!is_live_object(objspace, obj)) return ST_DELETE;
+    gc_mark_ptr(objspace, obj);
     return ST_CONTINUE;
 }