Avoid tracing shared TT_ENV object.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/gc.c b/src/gc.c
index 63eab8e00..5003f4b91 100644
--- a/src/gc.c
+++ b/src/gc.c
@@ -639,6 +639,7 @@ gc_mark_children(mrb_state *mrb, mrb_gc *gc, struct RBasic *obj)
       struct REnv *e = (struct REnv*)obj;
       mrb_int i, len;
 
+      if MRB_ENV_STACK_SHARED_P(e) break;
       len = MRB_ENV_STACK_LEN(e);
       for (i=0; i<len; i++) {
         mrb_gc_mark_value(mrb, e->stack[i]);