* cont.c (rb_fiber_start): don't enqueue Qnil to async_errinfo_queue.

  rb_vm_make_jump_tag_but_local_jump() could return Qnil (ex. when
  finished by Thread.exit). [ruby-dev:45218] [Bug #5993]

* test/ruby/test_fiber.rb (test_exit_in_fiber): add test for it.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38414 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 2 insertions, 1 deletions

diff --git a/cont.c b/cont.c
index 01800a6016..be8c982228 100644
--- a/cont.c
+++ b/cont.c
@@ -1174,7 +1174,8 @@ rb_fiber_start(void)
 	}
 	else {
 	    VALUE err = rb_vm_make_jump_tag_but_local_jump(state, th->errinfo);
-	    rb_threadptr_async_errinfo_enque(th, err);
+	    if (!NIL_P(err))
+		rb_threadptr_async_errinfo_enque(th, err);
 	}
 	RUBY_VM_SET_INTERRUPT(th);
     }