silverstripe/sapphire — pull request #1099 by uniun (2013-01-15 09:33:11+00:00)
Title: Impossible to unselect TreeDropdownField

It was impossible to unselect TreeDropdownField.
'!' operator should not be used at all and identical comparison (===) was too "strict" (self.getValue() returns string but $(node).data('id') returns number).