Bubbling submit events and nested forms

[disnet]

Although nested forms are disallowed, you can still construct a DOM with nested forms dynamically:

let inner = document.createElement('form');
inner.setAttribute('id', 'inner');
let outer = document.createElement('form');
outer.setAttribute('id', 'outer');
outer.appendChild(inner);

document.body.appendChild(outer);

Oddly enough when you do this, a submit event dispatched from the inner form does not bubble up to the outer form.

document.getElementById('outer').addEventListener('submit' e => {
  console.log('never fires for submit events dispatched on inner');
}, false);

This seems to be the case for all modern browsers (but not at least IE 11, I haven't tested earlier IEs).

I would think this behavior should be specified in the event dispatch section of the spec but I can't seem to find anything that would suggest the observed behavior.

Am I just misreading the spec or is this behavior currently unspecified?

[annevk]

See #687 and whatwg/html#3599 in particular.

I think what mainly needs to happen at this point is writing somewhat exhaustive tests and then patching the dispatch algorithm in whatever way is needed for this.