rails/rails — pull request #15262 by georgebrock (2014-05-23 06:57:54+00:00)
Title: Fix *_ids method for has_many with primary_key

A `has_many` association with a custom `primary_key` was using the wrong primary key field name to find the list of associated IDs.

See https://github.com/rails/rails/issues/14439 for details.