2018797 - Enable layout.abspos.fragmentainer-aware-positioning.enabled on Nightly only

Status: RESOLVED FIXED

(Core :: Layout: Positioned, task)

Description

[Ting-Yu Lin [:TYLin] (PST, UTC-7)]

Once bug 2016960, bug 2009647, and bug 2016963 are fixed, we will be ready to turn on layout.abspos.fragmentainer-aware-positioning.enabled.

If these bugs are fixed relatively soon, say in the beginning of Firefox 150 Nightly cycle, I propose enabling the pref in Nightly only at first, because I'll be away for the last three week of Firefox 150 Nightly cycle, and won't be available to address any issues. Enabling it in Nightly during that time would still allow us to gather additional testing.

If the feature requires more time to polish, any regressions will remain confined to Nightly. Otherwise, if it looks ready to ship, once the Firefox 151 Nightly cycle starts, we can land the shipping patch in bug 2002115 and uplift to Beta.

Comment 1

[Ting-Yu Lin [:TYLin] (PST, UTC-7)]

Attachment: Bug 2018797 - Enable layout.abspos.fragmentainer-aware-positioning.enabled on Nightly only. r?#layout

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/1b499d6c7bc9
https://hg.mozilla.org/integration/autoland/rev/282c37caf62f
Enable layout.abspos.fragmentainer-aware-positioning.enabled on Nightly only. r=layout-reviewers,hiro

Comment 3

[Atila Butkovits]

https://hg.mozilla.org/mozilla-central/rev/282c37caf62f

Comment 4

[Dianna Smith [:diannaS]]

:TYLin did you want to mention this in the 150 nightly release notes? Feel free to nominate if so.

Comment 5

[Ting-Yu Lin [:TYLin] (PST, UTC-7)]

Release Note Request (optional, but appreciated)
[Why is this notable]: Enabling the pref addresses incorrect positioning and fragmentation of absolutely positioned elements across multi-column container, improving interoperability with other browsers. It also prevents layout glitches (e.g. overlapping text) or content loss when printing absolutely positioned elements.
[Affects Firefox for Android]: Yes.
[Suggested wording]: Starting with Firefox 150, Firefox Nightly improves the rendering of absolutely positioned elements across multi-column containers and in printing, ensuring a more accurate element positioning and fragmentation.
[Links (documentation, blog post, etc)]: N/A

Comment 6

[Dianna Smith [:diannaS]]

Added to Fx150 nightly notes where it will remain for 3 cycles or until layout.abspos.fragmentainer-aware-positioning.enabled is enabled by default.

Comment 7

[Vadim Makeev]

FYI, documented this flag in the experimental features section of the Firefox 150 release notes for developers on MDN (PR)

Comment 8

[Ryan VanderMeulen [:RyanVM]]

Removed from the Nightly 152 release notes as the feature is riding the trains in Fx151 and bug 2002115 will cover that release note.