I'm still working on this. Technically, now unit test reproduces exactly the situation described in bug (it can be reproduced when form has `action=""` as well). However, the whole test suite has other issues (that were reproduced on master as well):
* fails 7 assertions in the test "Route: index delta" on Android (both in Chrome and in stock browser);
* completely blows up in Chrome for iOS (looks like navigation back in Chrome for iOS has other issues).

On devices it works perfectly only in Safari on iOS 6.1.4 and in desktop browsers.
I cannot claim it as done because of mentioned issues :-/