Our implementation is totally not what the spec says, but totally what other
UAs do, see https://github.com/w3c/csswg-drafts/issues/2474.
So given this is causing webcompat pain, I think we should be pragmatic and just
unprefix this.
We could keep serialization and getComputedStyle with ::selection working with a
bit more effort, like we do for :-moz-placeholder, but I'd prefer not doing at
least the serialization bit, and just alias in nsCSSPseudoElements
:-moz-selection to selection too.
Bug: 509958
Reviewed-by: dbaron,xidorn
MozReview-Commit-ID: 6lxctozRDqv
Much like we optimize to_ascii_lowercase.
This also fixes a bug in Servo where attr() rules with an unknown namespace
prefix are parsed, which is wrong.
Unfortunately this means that we lose the NS_STYLE_INHERIT_BIT optimization to
avoid posting changes if we had not requested the struct. In practice, I'm not
sure this optimization matters much, though, and we already compare all the
structs anyway.
We _could_ keep a weak parent pointer from the text style if needed, given we're
going to keep alive the text style at least until the parent style context goes
away, so should be safe, but I don't think the extra churn is worth it, to be
honest. Happy to do so as part of bug 1368290 if you think it's worth it.
Bug: 1385896
Reviewed-by: heycam
MozReview-Commit-ID: ka6tNwf4Ke
