From 7d8abee751f4a781ed4bfa7a06cdade9aebdb0ca Mon Sep 17 00:00:00 2001
From: Roland Walker <walker@pobox.com>
Date: Mon, 10 Feb 2014 10:53:30 -0500
Subject: [PATCH] don't choke when :args is not present

in _process_options
---
 lib/cask/system_command.rb | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/cask/system_command.rb b/lib/cask/system_command.rb
index 024673615..ce2519ed2 100644
--- a/lib/cask/system_command.rb
+++ b/lib/cask/system_command.rb
@@ -37,7 +37,8 @@ class Cask::SystemCommand
     if options[:sudo]
       command.unshift('/usr/bin/sudo', '-E', '--')
     end
-    if ! options[:args].empty?
+    if options.key?(:args) and
+        ! options[:args].empty?
       command.concat options[:args]
     end
     command