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DOM4 not compatible with ACID3 tests

From: Jonas Sicking <jonas@sicking.cc>
Date: Thu, 8 Sep 2011 00:23:22 -0700
Message-ID: <CA+c2ei-rCN3Xaqx6-zuswQQMtaGTXu9JpHoWtpLQqvYxPsL4Kg@mail.gmail.com>
To: Webapps WG <public-webapps@w3.org>, Ian Hickson <ian@hixie.ch>
Hi All,

The new DOM-Core specification changes some of the behavior for
DocType nodes to make them act more like all other nodes in the DOM.
Specifically:

1. They always have a ownerDocument
2. They can move between, both using explicit calls to AdoptNode, and
implicit adoption during for example insertBefore
3. They can be cloned between documents using importNode

We've written a patch to implement these changes in Gecko (which
resulted in a nice reduction in code). However, ACID3 tests for the
old behavior which is making it a harder decision to check this patch
in. As I understand it this isn't a Gecko specific interaction with
ACID3, but all browsers will see the same loss in ACID3 score if they
implement the new DOM-Core spec.

Because of this we've been reluctant to land said patch. I would
expect the engines that currently score 100/100 to be even more
reluctant to lose a point or two.

The obvious fix here seems to me to change ACID3. It would suck if the
ACID3 tests are what is holding the web back. However so far I haven't
been able to get a response from the parties that can make that
happen.

Additionally, ACID3 contains some attribute-node tests which runs a
big risk of making it hard to implement other parts of DOM-Core. My
understanding is that in theory it's possible to implement the
DOM-Core spec if it's implemented exactly as currently specced. But if
that turns out to break too many websites right now, then we won't be
able to experiment with alternative strategies since they would break
ACID3.

Again, I've poked the people that can change ACID3 about this too, but
so far without success.

I also haven't checked, but if ACID3 is testing mutation events, then
that will likely hold back deprecating them from the web too.

Should we change the course here for the DOM4 spec and declare ACID3
as set in stone and anything that breaks it is to be considered not
web compatible? This would seem like a ridiculous solution to me, but
if browsers won't implement changes that break ACID3, which I strongly
suspect is the case, and if ACID3 can't be changed, then I don't
really see much alternative.

/ Jonas
Received on Thursday, 8 September 2011 07:24:20 GMT

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