[csswg-drafts] [css-lists] Initial value of counter-increment needs to be something different from none (#3686)

MatsPalmgren has just created a new issue for https://github.com/w3c/csswg-drafts:

== [css-lists] Initial value of counter-increment needs to be something different from none ==
Background: we (Gecko) have implemented the `counter-set` property, the built-in `list-item` counter for `<ol>/<li>` etc, and the `::marker` pseudo for rendering.  This all works fine, with one exception:  `counter-increment` should be automatically set on [list items](https://drafts.csswg.org/css-lists-3/#declaring-a-list-item), which means its value depends on the computed value of `display`.  This means it's impossible to implement this in the UA sheet so we "adjust" the computed value in the style engine instead.  At that point though, an author-specified `counter-increment:none` is lost if the initial value is `none`.

The natural solution to this problem is to change the initial value to something else, e.g. `auto`, which then computes to the relevant `list-item` counter value on [list items](https://drafts.csswg.org/css-lists-3/#declaring-a-list-item) and to `none` on other elements.

(A quick resolution would be most welcome since it blocks shipping this new implementation (which fixes a bunch of decades-old HTML list counter bugs in Gecko).)

CC @emilio @fantasai 

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/3686 using your GitHub account

Received on Thursday, 28 February 2019 00:25:52 UTC