jquery/jquery-ui — pull request #1212 by epowers (2014-03-11 18:59:04+00:00)
Title: Selectable: fix mousedown on hierarchical selectable items

Added unit test that fails before fix.
Original bug involved the order of array merging when using
.parents().addBack(), and the fix uses .closest() which both
solves the ordering problem and should speed up the mousedown
handler.

Fixes #9914