twitter/bootstrap — pull request #3550 by jorgenfb (2012-05-20 18:24:21+00:00)
Title: Clear tooltips delayed show timer when leave event is triggered. ALSO when hide delay is 0.

Cancel running timer for tooltips with delayed show, but instant hide. This prevents delayed tooltips from appearing if the mouse leaves the elements before tooltip is showed and the hiding delay is 0.

Unit test "should not show tooltip if leave event occurs before delay expires, even if hide delay is 0" is provided in bootstrap-tooltip module.

Error is reproduced like this:
$(...).tooltip({delay: {show: 1000, hide: 0}});

Now let the mouse enter en leave the element within 1 second. The tooltip shows up after 1000 ms anyway.