rails/rails — pull request #9576 by fredwu (2013-03-05 23:47:46+00:00)
Title: [Backport to 3-2-stable] Don't reset inheritance_column when setting explicitly.

This is backported from master (cdfcbc4).

See pull request https://github.com/rails/rails/pull/5327

cc @tenderlove @jonleighton