zendframework/zf2 — pull request #4607 by ezimuel (2013-06-07 18:23:52+00:00)
Title: Added the backward compatibility support on bcrypt verify

Possible solution to the issue #4538. When the user explicit set the backwardCompatibility to true, the verify method of Zend\Crypt\Password\Bcrypt tries to substitute the new $2y$ with $2a$ if PHP < 5.3.7 (and generate a WARNING suggesting to upgrade to PHP 5.3.7+).
If backwardComaptibility is set to false the verify method throws and Exception with a message to upgrade to PHP 5.3.7+.