HTML 5 form still submits event if propagation stopped and invalid
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I'm writing some unit tests for an HTML 5 app that uses the HTML 5 form validation API. I've attached a `submit` event handler to the form that does some custom handling before serializing to JSON and passing it off to my server.

What I've discovered, though, is that if I initiate a jQuery `submit()` event on the form, even if it's invalid, not only does my submit handler get called, it _also_ executes the default submit action and posts to the server!

Instead, I'd expect my event handler not to have been called because the form is invalid. I'd also expect that _even if_ my event handler gets called, the default form submit action should not occur.

I've created a JSFiddle to demonstrate (tested in Chrome 20):

http://jsfiddle.net/jonbca/SYg4h/22/

So, what gives?