Added CSS 2

[SebastianZ]

This change adds everything introduced in CSS 2 Revision 1. It also moves tests of things into CSS 2 that were initially introduced there but were tested in other specs so far.

The tests include the deprecated clip property because browsers are still required to support it.

I skipped all aural properties like speak, cue, volume, etc. because they are non-normative and removed in the newest working draft of the spec.

Note that this should wait until #212 is merged, so we have a way to filter CSS 2 out. Though you can already review all the changes made. In the end I'll just add a filter that includes every spec. including CSS 2.

This closes #208.

Sebastian

[PolariTOON]

I have not reviewed all the changes yet, but two things already come to my mind:

• Since the published version of CSS2 is still a multipage spec, somewhat massive compared to individual CSS3 modules, could you split it in several virtual subspecs, one for each section, like what i did for SVG2? This way, features would be grouped by topic.
• As you said in the issue thread, we should likely refer to the "CSS2.2" revision for the published version for now, since the version you currently linked is not updated anymore and has this big warning message when we open it?

[SebastianZ]

@PolariTOON Thank you for the review!

I've now split up the specification into smaller ones covering the different parts as you suggested.
And I am also referring to CSS 2.2 in the links now.

Could you please make another review?

Sebastian

[PolariTOON]

I spotted some nits and maybe basic selectors and media queries could be tested, but overall this looks good.

[SebastianZ]

@PolariTOON Thank you for the detailed review! I've addressed everything you've mentioned. Could you please review it again?

Sebastian

[PolariTOON]

LGTM. It's interesting to see that some features that were introduced right back in CSS2 are still not fully supported nowadays in major browsers: orphans, widows, outline-color: invert...

[SebastianZ]

LGTM.

Thank you again for the reviews!

It's interesting to see that some features that were introduced right back in CSS2 are still not fully supported nowadays in major browsers: orphans, widows, outline-color: invert...

Yes, interestingly, according to MDN web docs it seems that outline-color: invert was implemented at some point though support for it got removed again from browsers.

And I just realized again why I didn't include the keyword initially. The spec. says this:

Conformant UAs may ignore the invert value on platforms that do not support color inversion of the pixels on the screen. If the UA does not support the invert value then the initial value of the outline-color property is the value of the color property, similar to the initial value of the border-top-color property.

So, as I merged the PR already, I guess I should create a new PR to remove the test for it again.

Sebastian

[SebastianZ]

And btw., the implementation of widows and orphans in Gecko is tracked in https://bugzil.la/137367, if you're interested in following it.

@LeaVerou There we have something that's unimplemented for 20 years. And I am sure they will be implemented at some point because Firefox is the only browser that doesn't support those properties and there is still author interest for them.

Sebastian

[SebastianZ]

And I just realized again why I didn't include the keyword initially. The spec. says this:

Conformant UAs may ignore the invert value on platforms that do not support color inversion of the pixels on the screen. If the UA does not support the invert value then the initial value of the outline-color property is the value of the color property, similar to the initial value of the border-top-color property.

I just removed it again in 93faed6.

Sebastian