doctrine/phpcr-odm — pull request #491 by dantleech (2014-05-08 18:32:10+00:00)
Title: Verify that aliases exist

When dispatching certain query builder nodes which do not rely
on a ODM mapping, no validation was being done on the alias existance.

This PR adds an explicit check for each one.

Fixes: https://github.com/doctrine/phpcr-odm/issues/488