From 1a9282914edacfe3c8d5c1366e1aacfe2d2893fc Mon Sep 17 00:00:00 2001
From: dearblue <dearblue@users.osdn.me>
Date: Sun, 7 Apr 2024 20:45:10 +0900
Subject: [PATCH] Fold the code for freeing `env`

Also, `e->stack = NULL` is not needed.
This is because "use-after-free" can be detected with `MRB_DEBUG` + `MRB_GC_STRESS`.
---
 src/gc.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/src/gc.c b/src/gc.c
index 533722a9b..f3c7e3c6b 100644
--- a/src/gc.c
+++ b/src/gc.c
@@ -761,13 +761,9 @@ obj_free(mrb_state *mrb, struct RBasic *obj, mrb_bool end)
     {
       struct REnv *e = (struct REnv*)obj;
 
-      if (MRB_ENV_ONSTACK_P(e)) {
-        /* cannot be freed */
-        e->stack = NULL;
-        break;
+      if (!MRB_ENV_ONSTACK_P(e)) {
+        mrb_free(mrb, e->stack);
       }
-      mrb_free(mrb, e->stack);
-      e->stack = NULL;
     }
     break;