Confusion with Get Parameter Name same as Form Field Name

I could verify that recovery after expiry works with parameters after the fix from issue 4014. This is more than what I could achieve with 1.4. After some more testing I found It breaks with the attached testcase where the GET parameter has the same name as the form field. I don't know whether this is out of scope.

Please use the link "Expiry Recovery Form with Parameters Test". In the code TestPageFormParameters.html, TestPageFormParameters.java, I have commented out the version that works and replaced it with the bad one.