thread.c: Mutex#synchronize no block params

* thread.c (rb_mutex_synchronize_m): yield no block params.  patch by
  splattael (Peter Suschlik) in [ruby-core:53773] [Bug #8097].
  fix GH-266.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40000 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 1 deletions

diff --git a/thread.c b/thread.c
index c510b93e9a..5312648a57 100644
--- a/thread.c
+++ b/thread.c
@@ -4567,7 +4567,7 @@ rb_mutex_synchronize_m(VALUE self, VALUE args)
 	rb_raise(rb_eThreadError, "must be called with a block");
     }
 
-    return rb_mutex_synchronize(self, rb_yield, Qnil);
+    return rb_mutex_synchronize(self, rb_yield, Qundef);
 }
 
 void rb_mutex_allow_trap(VALUE self, int val)