If attachment fails for whatever reason (e.g the host element is not
allowed to be a host), the HTML spec tells us to insert the template
element anyway and proceed.
Before this change, we were recomputing the insertion location at this
point, which caused it to be *inside* the template element. Inserting
the template element into itself didn't work, and so the DOM would end
up incorrect.
The fix here is to simply use the insertion point we determined earlier
in the same function, before putting a template element on the stack of
open elements. We already do this elsewhere.
Fixes at least 228 subtests on WPT. :^)
There are ARIA attributes, e.g. ariaControlsElements, which refer to a
list of elements by their ID. For example:
<div aria-controls="item1 item2">
The div.ariaControlsElements attribute would be a list of elements whose
ID matches the values in the aria-controls attribute.
The property-reflection.html test was partially split into a second file
recently, property-reflection-imperative-setup.html. Let's re-import to
ensure we have the latest. See:
2518df1
Let's simply reinsert the element respecting it's new position in the
DOM tree, instead of crashing.
Fixes regression in WPT tests caused by introducion of cache for
getElementById().
