On Fri, 10 Feb 2012 08:18:40 +0100, Boris Zbarsky <[email protected]> wrote:
On 2/9/12 9:51 AM, Simon Pieters wrote:
It is very likely that more quirks need to be added, but as I went
through the list I was surprised about how many of them were *not*
widely implemented across browsers, and so may not be needed for Web
compat and can be dropped.
It's worth keeping in mind that the IE9 mode relevant for quirks "web
compat" is the compat view quirks mode, as far as I can tell...
OK.
It would be useful if browser implementors could review the draft,
consider dropping quirks, give feedback about quirks that can't be
dropped, and consider aligning with other implementations for quirks
that are here to stay.
1) I'm fairly certain the "Images (img elements) without alt attributes
sometimes display placeholder icons in quirks mode." quirk cannot be
dropped. The real point of that quirk is that this markup:
<img width="100" height="100" src="404.html">
which links to some non-existent image needs to result in a box of width
100 and height 100 in quirks mode; not doing that breaks all the various
pages that (still) use "spacer gifs" pointing to bogus URIs.
I believe some UAs have this behavior in all modes; in Gecko the
behavior is restricted to quirks mode.
The HTML specification specifies this quirk in the Rendering section.
http://www.whatwg.org/specs/web-apps/current-work/multipage/rendering.html#images-0
2) The "fixed width specified on a table cell resets the nowrap
attribute." quirk seems to be implemented by everyone, effectively. I
would be really surprised if it can be dropped.
IE9 in non-compat view doesn't have it.
OK, so then either we limit this to quirks mode like Opera/Gecko or we
also do it in standards mode like WebKit/IE9 compat view.
3) Likewise for the "tables with no rows/rowgroups have zero height
even when a height is specified" quirk.
OK.
4) The CSS parsing quirks need to define behavior for shorthands.
Other than the behavior for 'font' (assuming 'font-size' is on the list),
what's missing? (My idea was that shorthands that reference other
properties (or value productions from other properties) in their "Value:"
specification would automatically support unitless lengths, e.g.
'background' where only <position> gets rewritten to use <quirklength>
because 'background-position' is in the list but 'background-size' is not.)
How was the list of properties for the unitless px quirk generated, by
the way?
I went through CSS2.1's property index manually.
It's interesting that 'font-size' is not in the list....
I trusted https://developer.mozilla.org/en/Mozilla_Quirks_Mode_Behavior
which says "The CSS parser interprets unitless numbers as px (except for
font-size because that was what Netscape Navigator 4 did...". :-) Now
added, but I'm not sure right now how to spec how the 'font' shorthand is
handled.
-Boris
Thanks!
--
Simon Pieters
Opera Software
