zendframework/zf2 — pull request #5100 by tux-rampage (2013-09-11 07:50:04+00:00)
Title: [ServiceManager] Implemented circular alias reference detection

ServiceManagers that allow overwriting the service definition may
contain circular references which will cause an infinite loop.

I extracted the alias resolving code to a protected method that will detect
circular references and throw an exception if one is encountered.