Honor all <option> descendants of <select> #249
Description
The spec says:
The list of options for a select element consists of all the option element children of the select element, and all the option element children of all the optgroup element children of the select element, in tree order.
https://html.spec.whatwg.org/#concept-select-option-list
Test-case:
data:text/html,<!doctype html>
<script>
var select = document.createElement("select");
select.appendChild(document.createElement("optgroup"));
select.firstChild.appendChild(document.createElement("optgroup"));
select.firstChild.firstChild.appendChild(document.createElement("option"));
document.documentElement.textContent = select.options.length;
</script>
IE11 outputs 0, per spec. Gecko and Chrome output 1. Assuming WebKit behaves the same as Blink, 3/4 of UAs will have to switch to match the spec. If the spec switched to match majority behavior, only 1/4 would have to switch. The behavior in this case is totally inconsequential, because the DOM in question cannot (AFAIK) be produced by the parser, so it's almost certainly not going to come up on real-world web pages. So I suggest we standardize on the majority behavior to ease interop.
Existing test for this behavior that would need to be changed: http://w3c-test.org/html/infrastructure/common-dom-interfaces/collections/htmloptionscollection.html (the test with "" in it)