rails/rails — pull request #9095 by bolthar (2013-01-28 12:53:49+00:00)
Title: counts.sum in alias_tracker.rb replaced by #inject

in alias_tracker.rb (activerecord), line 68, #sum is used instead of #inject. This breaks if the #sum method is not present somehow - which can happen if plugins like composite_primary_keys are used.