1924210 - Implement layout support for implicit anchor element

Status: NEW

(Core :: Layout: Positioned, enhancement)

Description

[David Shin[:dshin]]

Seems that there may be a HTML-attribute way to define anchor relationship on the way - See example 2.

Comment 1

[Jonathan Watt [:jwatt]]

In the spec I don't see an anchor attribute being defined (only a popover attribute):

https://html.spec.whatwg.org/multipage/indices.html#attributes-3

However, it seems that Google has added some WPT tests that support specifying an implicit anchor using an anchor attribute:

https://searchfox.org/mozilla-central/search?q=&path=tests%2F**%2Fthe-anchor-attribute-0&case=true&regexp=false

For example:

https://searchfox.org/mozilla-central/rev/8eb10f82706521e1b9cff8cd73119bb649a0cb2a/testing/web-platform/tests/html/dom/elements/global-attributes/the-anchor-attribute-001.tentative.html#28

Probably out of scope to support for M1, but something to be aware of that may come down the pike at some point if that get's spec'ed.

Comment 2

[Jonathan Watt [:jwatt]]

Also note that in the case of popover, the spec text for the popover attribute says:

...it will be rendered on top of other page content...

So we'll need to put it in the top, top-layer. (That is, this bug isn't as simple as just looking for an implicit element and passing that into pre-existing code.)