[css-lists] Does counter() create a new counter if none exists?

[Loirooriol]

Consider this code: https://jsfiddle.net/35kuzg5m/

<div>
  <p>aaa</p>
  <p>bbb</p>
</div>
<hr />
<div>
  <p>aaa</p>
  <p>bbb</p>
</div>

p::before {
  content: counter(c) '/ ';
  counter-increment: c 1;
}
div ~ div::before {
  content: counter(c, none);
}

It's rendered as:

Firefox and Chrome	Edge
1/ aaa 1/ bbb	1/ aaa 1/ bbb
1/ aaa 2/ bbb	1/ aaa 1/ bbb

In https://drafts.csswg.org/css-lists/#counter-functions I can't find anything that says that counter() can create a new counter, so it seems Edge is the only one that follows it.

[tabatkins]

Right, that sort of behavior is definitely not documented. I wasn't aware that it happened, or even remotely believed that it could. ^_^

[Loirooriol]

Oh, it seems Firefox and Chrome follow CSS 2.2:

If counter-increment or content on an element or pseudo-element refers to a counter that is not in the scope of any counter-reset, implementations should behave as though a counter-reset had reset the counter to 0 on that element or pseudo-element.

[tabatkins]

Sigh, cool, I must have missed that when I was drafting the Lists spec.

[fantasai]

Fixed see 09f1d2b and 848b8c6 and maybe a few changesets in between

[fantasai]

Marked Obvious Bugfix since we're supposed to be in sync with CSS2.1