From 1e21fdd67a97d3c698600ddea46abc4defedd275 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Thu, 22 Dec 2011 11:31:47 -0800
Subject: [PATCH] Do a block_given check on import so you can call it w/o a
 block

---
 lib/vagrant/driver/virtualbox.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/vagrant/driver/virtualbox.rb b/lib/vagrant/driver/virtualbox.rb
index fe590eeb7..f4b8dd023 100644
--- a/lib/vagrant/driver/virtualbox.rb
+++ b/lib/vagrant/driver/virtualbox.rb
@@ -179,7 +179,7 @@ module Vagrant
                 current = $1.to_i
                 if current > last
                   last = current
-                  yield current
+                  yield current if block_given?
                 end
               end
             end