Mouseenter doesn't fire on a disabled input element

[dmethvin]

This was done intentionally in jQuery.event.dispatch based on #6911 to normalize a cross-browser behavior. However it seems inadvisable for us to do it, at least for some set of events. We can easily revert the change but it will cause other bug reports.

Test case: ​http://jsfiddle.net/pm4JG/6/

[dmethvin]

I am thinking we may want to ban only click events with the idea that those are the most common events that should not appear on a disabled elements. The browser should never generate focus or blur on a disabled element so we shouldn't need to worry about them. Custom events or ones like mouseover would still occur, as would a program-created focus event because heaven forbid we should ever fail to fire a focus handler for an element that can't possibly receive focus.

[mikelehen@…]

Relatedly (I assume), this breaks mouseenter / mouseleave event delegation. I'm trying to handle them on the *parent* of a disabled input control, but they don't always fire. This seems like a definite bug. Repros in Chrome and Firefox.

​http://jsfiddle.net/u5HqK/2/

[jmarston]

Firefox and Chrome don't appear to raise any mouse events for disabled inputs or buttons. Which means only banning click events would reintroduce inconsistencies between browsers for events like mouseover

[dmethvin]

#11793 is a duplicate of this ticket.

[Dave Methvin]

Fix #11382. #11764. Only prevent click events on disabled elements.

We don't want a disabled link/button to register delegated clicks, but we do want events like mouseover or custom events.

This is a compromise, there is no perfect solution. Well, the browsers could be consistent about direct vs. delegated events but *that's* not gonna happen.

Changeset: 8a01c9201abb3a5311d5b0019b0322de89df6374