From cbeb392d7d04a21cb69df8102ed9141b6ebf5a74 Mon Sep 17 00:00:00 2001
From: dearblue <dearblue@users.osdn.me>
Date: Tue, 14 Jun 2022 22:31:45 +0900
Subject: [PATCH] Fixed possible inconsistency in `gc_protect()`

If `mrb_realloc()` raises an out-of-memory exception, `arena_capa` will hold the wrong value.
---
 src/gc.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/gc.c b/src/gc.c
index 0f5f21d26..4f55dc6ae 100644
--- a/src/gc.c
+++ b/src/gc.c
@@ -459,8 +459,9 @@ gc_protect(mrb_state *mrb, mrb_gc *gc, struct RBasic *p)
 #else
   if (gc->arena_idx >= gc->arena_capa) {
     /* extend arena */
-    gc->arena_capa = (int)(gc->arena_capa * 3 / 2);
-    gc->arena = (struct RBasic**)mrb_realloc(mrb, gc->arena, sizeof(struct RBasic*)*gc->arena_capa);
+    int newcapa = gc->arena_capa * 3 / 2;
+    gc->arena = (struct RBasic**)mrb_realloc(mrb, gc->arena, sizeof(struct RBasic*)*newcapa);
+    gc->arena_capa = newcapa;
   }
 #endif
   gc->arena[gc->arena_idx++] = p;