silverstripe/silverstripe-framework — pull request #3409 by theorytank (2014-08-20 14:06:24+00:00)
Title: FIX: belongs_many_many back to the same class type

Currently SS get's confused when referencing multiple of the same DataObject type in a belongs_many_many definition using the dot notation. It doesn't recognize the dot notation at all, and leaving it off means it will just choose the first match in the many_many definition which isn't correct. This adds in the dot check and reverse lookup functionality allowing for multiple definitions.

I couldn't find a bug referencing it specifically however there's lots of discussion in the forums and IRC so this problem does in fact exist.