Acceptance test that we can't add boxes with the same name

test/acceptance/box_test.rb

@@ -20,6 +20,18 @@ describe "vagrant box" do
     result.stdout.should match_output(:box_installed, "foo")
   end
 
+  it "errors if attempting to add a box with the same name" do
+    require_box("default")
+
+    # Add the box, which we expect to succeed
+    assert_execute("vagrant", "box", "add", "foo", box_path("default"))
+
+    # Adding it again should not succeed
+    result = execute("vagrant", "box", "add", "foo", box_path("default"))
+    result.should_not succeed
+    result.stderr.should match_output(:box_already_exists, "foo")
+  end
+
   it "gives an error if the file doesn't exist" do
     result = execute("vagrant", "box", "add", "foo", "/tmp/nope/nope/nope/nonono.box")
     result.should_not succeed

test/acceptance/support/output.rb

@@ -8,6 +8,10 @@ module Acceptance
       @text = text
     end
 
+    def box_already_exists(name)
+      @text =~ /^A box already exists under the name of '#{name}'/
+    end
+
     # Checks that an error message was outputted about the box
     # being added being invalid.
     def box_invalid