rails/rails — pull request #3732 by larskanis (2011-11-23 14:10:30+00:00)
Title: Fix associations with per-class/multiple database connections

Current ActiveRecord does not work with per class database connections. It worked with 2.x series.

Here is a simple example, running against the ActiveRecord test database: https://gist.github.com/1388725
It throws ActiveRecord::ConnectionNotEstablished in line 16 without this patch.