1760734 - Deprecate -moz-hidden-unscrollable

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, defect)

Description

[Karl Dubost💡 :karlcow]

I wonder if -moz-hidden-unscrollable could be deprecated.
It has created at least one webcompat issue.
https://github.com/webcompat/web-bugs/issues/101202

On https://searchfox.org/mozilla-central/rev/1c54648c082efdeb08cf6a5e3a8187e83f7549b9/testing/web-platform/tests/css/css-overflow/overflow-body-propagation-010.html#10
it was said in the code

overflow: -moz-hidden-unscrollable; /* will be removed in bug 1531609 */

But it was not removed in the end in Bug 1531609. And it became an alias of overflow: clip.

https://searchfox.org/mozilla-central/rev/1c54648c082efdeb08cf6a5e3a8187e83f7549b9/servo/components/style/values/specified/box.rs#2079-2087
https://searchfox.org/mozilla-central/search?q=moz-hidden-&path=&case=false&regexp=false

We probably need TELEMETRY to assert the usage and the webcompat risks of removing it.

Comment 1

[Karl Dubost💡 :karlcow]

It has created at least one webcompat issue.
https://github.com/webcompat/web-bugs/issues/101202

Removing -moz-hidden-unscrollable would solve that issue.

html {
          overflow-y: scroll;
          overflow: -moz-hidden-unscrollable;
          height: 100%;
        }

Comment 2

[Dennis Schubert [:denschub]]

While the user can't workaround the issue, we can ship an intervention with relative ease. We only have one known breakage so far, so setting this as P3 for now.

Comment 3

[Emilio Cobos Álvarez (:emilio)]

The problem with telemetry is that that doesn't give us a lot of visibility on stuff like overflow: -moz-hidden-unscrollable; overflow: clip;, which is a legit use of the old name to support older Firefox. But honestly I think we can probably just give it a try on nightly for a while.

Comment 4

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1760734 - Put overflow: -moz-hidden-unscrollable behind a pref on Nightly. r=#style,#layout-reviewers

Comment 5

[Emilio Cobos Álvarez (:emilio)]

(In reply to Karl Dubost💡 :karlcow from comment #0)

On https://searchfox.org/mozilla-central/rev/1c54648c082efdeb08cf6a5e3a8187e83f7549b9/testing/web-platform/tests/css/css-overflow/overflow-body-propagation-010.html#10
it was said in the code

overflow: -moz-hidden-unscrollable; /* will be removed in bug 1531609 */

To be clear that test was talking about removing that linenin the test btw (which is redundant once you support clip)

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e8215bd8f4db
Put overflow: -moz-hidden-unscrollable behind a pref on Nightly. r=dholbert

Comment 7

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

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/33321 for changes under testing/web-platform/tests

Comment 8

[Atila Butkovits]

https://hg.mozilla.org/mozilla-central/rev/e8215bd8f4db

Comment 9

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

Upstream PR merged by moz-wptsync-bot