Triggering beforeunload throws exception

[fejesjoco]

The following code:

$(window).on("beforeunload", function() { return "nooooooo"; });
$(window).triggerHandler("beforeunload");

Result in an error: TypeError: event.originalEvent is undefined

[fejesjoco]

 http://jsfiddle.net/zCGfY/

[fejesjoco]

I checked out the offending lines, I see there's some kind of magic converting between browser-native and jQuery event objects. Please make sure there is some way to find out the result of the beforeunload handler, because that's the whole purpose of triggering the event manually. (I am putting an iframe inside a dialog. When closing the dialog, I want to check if the loaded page lets me do that.)

[Dave Methvin]

Event: Allow triggerHandler(beforeunload)

Fixes #14791

Changeset: 06adf7c95d93507908181995a9ea15fe2729595a