2072683 - Positioned element taller than the scrollport anchored to a sticky anchor causes infinite scrolling

Status: RESOLVED FIXED

(Core :: Layout: Positioned, defect)

Description

[David Shin[:dshin]]

Attachment: Minimum Reproducible Case

STR: Load attached testcase, scroll down
Expected: Scroll stops at some point
Actual: Scroll keeps extending

Comment 1

[BugBot [:suhaib / :marco]]

Set release status flags based on info from the regressing bug 2057630

:TYLin, since you are the author of the regressor, bug 2057630, could you take a look?

For more information, please visit BugBot documentation.

Comment 2

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

I'll investigate this.

Comment 3

[BugBot [:suhaib / :marco]]

Set release status flags based on info from the regressing bug 2057630

Comment 4

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

Attachment: Bug 2072683 Part 1 - Add AnchorPosReferenceData::AppliedScrollShift(). r?#layout

Next part will split mDefaultScrollShift into two values. Route the current
users of the variableh to use the accessor instead.

This patch does not change behavior.

Comment 5

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

Attachment: Bug 2072683 Part 2 - Keep the default scroll shift out of scrollable overflow. r?#layout

This patch splits the original mDefaultScrollShift value into two. One is part
of the layout scroll shift, including the sticky scroll shift, and the possible
script shift prior to the first scroll update. The other is post layout scroll
shift, which is intended to be excluded from the scrollable overflow area, to
avoid the feedback loop.

Comment 6

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

Attachment: Bug 2072683 Part 3 - Add WPTs for the scrollable overflow of scroll-compensated anchored elements. r?#layout

anchor-scroll-010.html covers the original testcase in the bug.

anchor-scroll-011.html is another testcase that an positioned element's
scrollable overflow area may wrongly contribute to its scroll container's while
scrolling the anchor element.

anchor-scroll-012.html coverts the overflow areas update when switching the
position fallbacks. That is, the test would fail if aOct.AddFrame() call is
removed in TriggerFallbackReflow().

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/0374ed503626
https://hg.mozilla.org/integration/autoland/rev/4313c08e9942
Part 1 - Add AnchorPosReferenceData::AppliedScrollShift(). r=layout-reviewers,emilio
https://github.com/mozilla-firefox/firefox/commit/89bfb6b2a1ab
https://hg.mozilla.org/integration/autoland/rev/300a9637f7dc
Part 2 - Keep the default scroll shift out of scrollable overflow. r=layout-reviewers,emilio,dshin
https://github.com/mozilla-firefox/firefox/commit/2421a05e7a40
https://hg.mozilla.org/integration/autoland/rev/12339dae030e
Part 3 - Add WPTs for the scrollable overflow of scroll-compensated anchored elements. r=layout-reviewers,dshin

Comment 8

[agoloman]

https://hg.mozilla.org/mozilla-central/rev/4313c08e9942
https://hg.mozilla.org/mozilla-central/rev/300a9637f7dc
https://hg.mozilla.org/mozilla-central/rev/12339dae030e

Comment 9

[BugBot [:suhaib / :marco]]

The patch landed in nightly and beta is affected.

:TYLin, please make an uplift decision for beta:

• For beta, nominate the patch for beta uplift approval if the fix should be included in this release, or set status-firefox159 to wontfix if the fix can wait for the next release.

See Requesting an Uplift for documentation on how to request an uplift.

For more information, please visit BugBot documentation.

Comment 10

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/63709 for changes under testing/web-platform/tests

Comment 11

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Upstream PR merged by moz-wptsync-bot

Comment 12

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

The fix is large, so let's have it ride the train.