From 47bd44fce1a441919595de9000ced6f871973b70 Mon Sep 17 00:00:00 2001
From: "Yukihiro \"Matz\" Matsumoto" <matz@ruby-lang.org>
Date: Thu, 15 Jun 2017 15:16:56 +0900
Subject: Prevent Fiber#initialize to be called twice; fix #3705

---
 mrbgems/mruby-fiber/src/fiber.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/mrbgems/mruby-fiber/src/fiber.c b/mrbgems/mruby-fiber/src/fiber.c
index 3c3630a61..a0faafe28 100644
--- a/mrbgems/mruby-fiber/src/fiber.c
+++ b/mrbgems/mruby-fiber/src/fiber.c
@@ -74,6 +74,9 @@ fiber_init(mrb_state *mrb, mrb_value self)
 
   mrb_get_args(mrb, "&", &blk);
 
+  if (f->cxt) {
+    mrb_raise(mrb, E_RUNTIME_ERROR, "cannot initialize twice");
+  }
   if (mrb_nil_p(blk)) {
     mrb_raise(mrb, E_ARGUMENT_ERROR, "tried to create Fiber object without a block");
   }
-- 
cgit v1.2.3