In functional tests, unhandled exception in controller method leads to 200 response instead of 500

When a controller method throws an unhandled exception, under normal circumstances this leads to 500 error page. However if I make request to the same method from the functional test, I get a 200 OK response.

This really breaks my functional testing, as my tests can not catch a bug which can be easily seen if opening the page manually in a browser.

To get my error I need either to use selenium test (which is slow, but it gets same result as a browser) or to wrap controller method into:

try { ... } catch (Exception ex) { error() }

In case of explicit error() call the functional test gets correct 500 return code.

I created a sample webapp, where Application.index() method throws a runtime exception and a functional test checks that its return status is 500:
https://drive.google.com/file/d/0B72ZMlJTpA1VLWxpd0lMWk5JSHM/view?usp=sharing

Reproduce the issue with the linked sample webapp, where Application.index() throws a runtime exception during a functional test. Compare the functional-test response with the browser behavior and the explicit error() case. Done when an unhandled controller exception produces a 500 status in the functional test.