Delegating events with .on and specifying a classname of ".watch" causes an error on Firefox (15.0.1, Mac). Appears to do with a there being a function named watch in Gecko (https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Global_Objects/Object/watch)?

See http://jsfiddle.net/wmNAR/1/ for a test.

$('div').on('click', 'p.watch', function(e) {console.log('this creates an error.')

Causes an error:

"TypeError: pattern.test is not a function"

On this line (4260):

return pattern.test( elem.className || (typeof elem.getAttribute !== strundefined && elem.getAttribute("class")) || "" );