1522455 - multi-line text selection is displayed over a sticky header

Status: VERIFIED FIXED

(Core :: Web Painting, defect, P2)

Description

[phennim]

Attachment: text_selection_z-index_bug.gif

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:64.0) Gecko/20100101 Firefox/64.0

Steps to reproduce:

1. Visit https://bugs.chromium.org/p/chromium/issues/detail?id=147
2. Make a text selection that contains a "CR/LF"
3. Scroll up so that the selected text goes under the sticky header

Actual results:

(Part of) the selected lines are rendered on top of the sticky header.

Expected results:

The selected text should not be visible when under the header.

Comment 1

[Mats Palmgren (inactive)]

The STR seems to work fine for me using a Nightly on Linux.
It seems likely this is some kind of painting issue rather than Layout.

Comment 2

[Gingerbread Man]

Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:66.0) Gecko/20100101 Firefox/66.0
20190125215013

I can reproduce this on Windows, based on attachment 9038793 [details] rather than comment 0:

1. https://bugs.chromium.org/p/chromium/issues/detail?id=147
2. Select from "tabs" to "2. Close the who"
3. Using the mousewheel, scroll down.

Comment 3

[Alice0775 White]

Attachment: reduced html

Comment 4

[Alice0775 White]

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=6415ccbf739f36f71548540bd92c3b86ab9e1529&tochange=d112cf7b2b60e6244099dc3b599a2444ba0d1da3

Regressed by: Bug 1443027

Comment 5

[Miko Mynttinen]

Can reproduce on macOS.

Comment 6

[Pascal Chevrel:pascalc]

This is prioritized as a P2 with no assignee since January, could we either get an assignee or decide that this should be a P3? Thanks

Comment 7

[Matt Woodrow (:mattwoodrow)]

Attachment: Bug 1522455 - Position sticky can be handled by the compositor, so should be considered an async AGR. r?miko

Comment 8

[Matt Woodrow (:mattwoodrow)]

Didn't have success making an automated test for this, even making a selection from JS still results in the correct behaviour.

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/267df62ca84e
Position sticky can be handled by the compositor, so should be considered an async AGR. r=miko

Comment 10

[Cristina Coroiu [:ccoroiu]]

https://hg.mozilla.org/mozilla-central/rev/267df62ca84e

Comment 11

[Alexandru Trif, Desktop Test Engineering [:atrif]]

Hello,
Reproduced the issue using the test case from comment 3 with Firefox 66.0a1 (20190124214415) on Windows 10x64 and macOS 10.14.
The issue is verified using Firefox 68.0b12 (20190619234730) and Firefox 69.0a1 (20190624213657) on Windows 10x64, macOS 10.14 and Ubuntu 18.04.