Issue #2504139 by borisson_, Wim Leers, plach, prashantgoel, Fabianx,...

Issue #2504139 by borisson_, Wim Leers, plach, prashantgoel, Fabianx, dawehner, David_Rothstein, effulgentsia: Blocks containing a form include the form action in the cache, so they always submit to the first URL the form was viewed at