core: if box is unversioned, check update does nothing

lib/vagrant/action/builtin/box_check_outdated.rb

@@ -28,7 +28,12 @@ module Vagrant
             # message anyways.
             raise Errors::BoxOutdatedNoBox, name: machine.config.vm.box
           end
+
           box = machine.box
+          if box.version == "0" && !box.metadata_url
+            return @app.call(env)
+          end
+
           constraints = machine.config.vm.box_version
 
           env[:ui].output(I18n.t(

test/unit/vagrant/action/builtin/box_check_outdated_test.rb

@@ -72,6 +72,18 @@ describe Vagrant::Action::Builtin::BoxCheckOutdated do
     end
   end
 
+  context "with a non-versioned box" do
+    it "does nothing" do
+      box.stub(metadata_url: nil)
+      box.stub(version: "0")
+
+      app.should_receive(:call).once
+      box.should_receive(:has_update?).never
+
+      subject.call(env)
+    end
+  end
+
   context "with a box" do
     it "sets env if no update" do
       box.should_receive(:has_update?).and_return(nil)