[css-syntax] "Drop first @charset rule" seems unneeded.

[tabatkins]

In the comments in WICG/construct-stylesheets#84, @bzbarsky expresses some confusion as to the point of the "drop the first @charset rule" in the "parse a stylesheet" algorithm. After some review, I agree with him: I'm also confused!

I think this was added to express the previous Blink behavior of keeping @charset rules in the CSSOM, except for the first which was dropped. (Firefox apparently never dropped the first one...) Later, I went more scorched-earth and just declared that there was no such thing as a @charset rule (just an encoding declaring that happened to resemble one...), and so all @charset rules should be dropped from the CSSOM.

Since browsers seem to follow the newer Syntax advice to just drop all @charset rules, we can eliminate the explicit "drop first" rule from the spec.

Agenda+ to confirm with WG, as this spec is CR. ^_^ (I should also probably ask for republication, if I don't already have a pending permission...)

[fantasai]

(Fwiw, since it's CR, you'll need a DoC and a Changes list to publish.)

[css-meeting-bot]

The CSS Working Group just discussed "Drop first @charset rule" seems unneeded., and agreed to the following:

• RESOLVED: Drop the drop the first @charset rule

The full IRC log of that discussion

<dael> Topic: "Drop first @charset rule" seems unneeded.
<TabAtkins> GitHub: https://github.com//issues/3464
<dael> TabAtkins: This is in CR so need resolution. Way back in the day when I wrote syntax I spec blink's behavior of dropping the first. I later changed things so char-set tules were not rules. None of the charset things show in cssom. Everyone adapted to that, at least blink and FF. There is no @charset so we can drop the requirement to drop the first
<dael> TabAtkins: Looking for obj and, if not, I'll fix the spec and then put together the stuff for publising
<dael> AmeliaBR: @charset is now an unrecognized rule or is it recognized as a parsing instruction and then removed from CSSOM?
<dael> TabAtkins: Unrecgnoized rule. It's dropped like and @foo rule
<dael> fantasai: Proposal is drop all instead of drop first?
<dael> TabAtkins: There's already rules to drop all. but there's also a rule to say drop first. This is nonsensical so I want to fix.
<dael> fantasai: So spec says in one place it's drop first and in another place drop all
<dael> TabAtkins: Yeah
<dael> astearns: I'm in favor of fixing things Boris finds confusing
<dael> fantasai: If Mozilla signs off I'm fine
<dael> TabAtkins: I think Boris effectively did
<dael> astearns: What about webkit?
<dael> astearns: Prop: Drop the drop the first @charset rule
<dael> RESOLVED: Drop the drop the first @charset rule
<dael> TabAtkins: This is the only unresolved thing. It's due for a publication so I'll put together DoC. But if no one objects I'd like ar esolution to publish
<dael> astearns: I'd like to see the DoC since it's been a long time.
<dael> TabAtkins: No problem. There's been a couple changes
<dael> astearns: I don't expect many, but knowing which will be useful
<dael> TabAtkins: Last publish was in 2014

[tabatkins]

Tested in web-platform-tests/wpt@388ba3a