The mutation algorithms now more closely follow the spec and
fixes some assertion failures in tests such as Acid3 and Dromaeo.
The main thing that is missing right now is passing exceptions to the
bindings layer. This is because of issue #6075. I spent a while trying
to work it out and got so frustrated I just left it as a FIXME. Besides
that, the algorithms bail at the appropriate points.
This also makes the adopting steps in the document more spec compliant
as it's needed by the insertion algorithm. While I was at it, I added
the adoptNode IDL binding.
This adds a bunch of ancestor/descendant checks to TreeNode as well.
I moved the "remove_all_children" function to Node as it needs to use
the full remove algorithm instead of simply removing it from
the child list.
This is because it includes the initial node that the function was
called on, which makes it "inclusive" as according to the spec.
This is important as there are non-inclusive variants, particularly
used in the node mutation algorithms.
(...and ASSERT_NOT_REACHED => VERIFY_NOT_REACHED)
Since all of these checks are done in release builds as well,
let's rename them to VERIFY to prevent confusion, as everyone is
used to assertions being compiled out in release.
We can introduce a new ASSERT macro that is specifically for debug
checks, but I'm doing this wholesale conversion first since we've
accumulated thousands of these already, and it's not immediately
obvious which ones are suitable for ASSERT.
Since Web::Bindings::WindowObject inherits from JS::GlobalObject, it
cannot also inherit from Web::Bindings::EventTargetWrapper.
However, that's not actually necessary. Instead, we simply set the
Window object's prototype to the EventTargetPrototype, and add a little
extra branch in the impl_from() function that turns the JS "this" value
into a DOM::EventTarget*.
With this, you can now call window.addEventListener()! Very cool :^)
Fixes#4758.
