mongodb/mongo-php-driver — pull request #502 by bjori (2013-08-06 00:14:23+00:00)
Title: PHP-844: Authenticate before calling isMaster()

This is effectively (although not literally) a revert of
c5254c76297e8c48ceef3a2f1f36f3f9c274e744

Turns out, arbiters have a issue with this so this feature has been put
on hold by mongod