1645937 - scrollbars lost since Bug 1644271 and Bug 1645520 didn't resolve it

Status: VERIFIED FIXED

(Core :: Panning and Zooming, defect, P2)

Description

[atlanto]

On
LinuxMint(19.3 mate),
XGA(1024x768) display,
unmaximized window or showing sidebar,
some sites(e.g. https://www.yahoo.co.jp/ http://forums.mozillazine.org/ https://www.itmedia.co.jp/ https://distrowatch.com/)
scrollbars are not displayed.
(apz.allow_zooming=false (default), apz.mvm.force-enabled=true (default))

Scrollbars are displayed when apz.mvm.force-enabled=false.

Comment 1

[Kartikaya Gupta (email:[e-mail])]

Hm, weird. looks like the scrollbars are positioned "outside the root content" rather than "inside the visual viewport". So if the content is wider than the window the vertical scrollbar is clipped by the window. Same for horizontal scrollbar.

I can investigate. Possibly one of my other patches for bug 1644271 will end up fixing this.

Comment 2

[Kartikaya Gupta (email:[e-mail])]

Doesn't look like my patch queue for bug 1644271 fixes this, I'll need to investigate.

Comment 3

[Kartikaya Gupta (email:[e-mail])]

Replacing this GetIsViewportOveridden call with false seems to fix the problem. GetIsViewportOverridden just checks for the existence of an MVM, so presumably whatever other code this is meant to be in sync with is checking more than just the existence of an MVM. Probably for the allow_zooming flag or mobile viewport support. I can look more tomorrow, no time left today.

Comment 4

[Kartikaya Gupta (email:[e-mail])]

I think that code was only needed with containerful scrolling which is no longer a thing. In particular it seems related to the line that was removed here, so we should be able to set it to false unconditionally now. Maybe.

Comment 5

[Kartikaya Gupta (email:[e-mail])]

https://treeherder.mozilla.org/#/jobs?repo=try&group_state=expanded&revision=8082296b151ef8a4d8e4495f779eaf099a921f6e

Comment 6

[Kartikaya Gupta (email:[e-mail])]

Attachment: Bug 1645937 - Adjust when the root scrollframe gets a clip. r?tnikkel

Comment 7

[Kartikaya Gupta (email:[e-mail])]

Attachment: Bug 1645937 - Add reftest. r?tnikkel

Depends on D80054

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/c1021d851157
With containerless scrolling we always want this clip on the layer. r=tnikkel
https://hg.mozilla.org/integration/autoland/rev/e0f3090a46a4
Add reftest. r=tnikkel

Comment 9

[Atila Butkovits]

Backed outfor gv-junit failures on VerticalClippingTest.

Backout link: https://hg.mozilla.org/integration/autoland/rev/4d6e89cfbb2d8d9f9fbfc599e39e5e06401cb254

Push with failures: https://treeherder.mozilla.org/#/jobs?repo=autoland&resultStatus=testfailed%2Cbusted%2Cexception%2Crunnable&revision=e0f3090a46a4520b60b0795ae5973646d0e683ef&selectedTaskRun=YR5zc-HhRgqtdC1IZyLhUQ.0

Failure log: https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=306762989&repo=autoland&lineNumber=13019

Comment 10

[Kartikaya Gupta (email:[e-mail])]

I guess for some reason this breaks the clipping required by the setVerticalClipping API and/or dynamic toolbar. The dynamic toolbar sticky-pos tests are failing too, in addition to the gv-junit tests, on Android.

Obviously I can fix this by restoring the old behaviour on Android, by using UsesMobileViewportSizing instead of GetIsViewportOverridden, and I'll update the patch to do that. I'm not sure though if that condition is conceptually correct - maybe it needs to detect dynamic-toolbar-ness instead.

Comment 11

[Cosmin Sabou [:CosminS]]

kats, there are also these reftest failures:
https://treeherder.mozilla.org/logviewer.html#?job_id=306769813&repo=autoland

https://treeherder.mozilla.org/logviewer.html#?job_id=306777611&repo=autoland

Comment 12

[Kartikaya Gupta (email:[e-mail])]

Thanks. The updated patches should take care of those as well.

Comment 13

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/f444d609e7c3
Adjust when the root scrollframe gets a clip. r=tnikkel
https://hg.mozilla.org/integration/autoland/rev/f0d2b2411631
Add reftest. r=tnikkel

Comment 14

[Dorel Luca [:dluca]]

https://hg.mozilla.org/mozilla-central/rev/f444d609e7c3
https://hg.mozilla.org/mozilla-central/rev/f0d2b2411631

Comment 15

[Catalin Sasca, Desktop Test Engineering [:csasca]]

I was able to reproduce the issue on Firefox Nightly (2020-06-15) under Ubuntu 20.04 using the infos on Comment 0.

The issue is no longer reproducible on Firefox 79.0b4 and Firefox Nightly 80.0a1 (2020-07-06) under Ubuntu 20.04.