Don't provided final param if branch is nil

Factoid · Factoid · commit 953b8b57f492 · 2013-03-12T15:07:33.000-05:00
diff --git a/lib/git/lib.rb b/lib/git/lib.rb
@@ -493,7 +493,7 @@ def checkout(branch, opts = {})
       else
         arr_opts << '-b' << opts[:new_branch] if opts[:new_branch]
       end
-      arr_opts << branch
+      arr_opts << branch if branch
       
       command('checkout', arr_opts)
     end
