twbs/bootstrap — pull request #10801 by Travesty3 (2013-09-25 13:05:24+00:00)
Title: Add 'collapse' class back after expanding

The `collapse` class is replaced with the `collapsing` class while expanding, but it is never added back after the animation is complete. This functionality was changed for v3.0.0, but I think this detail was overlooked.

This breaks at least one third-party plugin: http://tarruda.github.io/bootstrap-datetimepicker/