Fix GoogleLogin button creation for Special:UserLogin
Fix GoogleLogin button creation for Special:UserLogin

HTMLForm::setAction changes the action of the form html element, but
not the hidden title input. If a request parameter is set in the URL
(GET) and send with POST (which is the method used for the Googlelogin
HTMLForm), the value of the global $_POST variable is used in WebRequest.
Because of that, the hidden title element of the form is observed when
the request is processed by MediaWiki, which is Special:UserLogin, even
if the GET value is Special:GoogleLogin. This results in the weird behaviour,
that in the URL the user sees Special:GoogleLogin but gets the contents
of Special:UserLogin.

This commit changes the way how the action is set to the HTMLForm. Instead
of using setAction, it now uses setTitle to set the correct context for
the HTMLForm.

Bug: T134504
Change-Id: I0d56b1634bf7657101b5c61ac2a50ed692276fb5

wikimedia/mediawiki-extensions-GoogleLogin,wikimedia/mediawiki-extensions-GoogleLogin