1518069 - graphical cursor affects the z-index on elements with 3d transformation (with preference: accessibility.browsewithcaret=true)

Status: VERIFIED FIXED

(Core :: Web Painting, defect, P3)

Description

[Robert Utasi [:hunboy]]

Attachment: zindexbug.html

Repro: see attchaed testcase, click next to the images on the screen to get graphical cursor on the screen.

AR: the cursor affects the z-index permanently on my platform. so image "blinks" with the cursor. Actually z-index "blinks", ignores z-index;

ER: graphical cursor doesn't affect the z-index.


Note: this is the minimum testcase, if I remove anything, the bug disappears. So summary:

- 3d-transform
- z-index defined

I could not find any workaround to fix this via css.

Some similar bug I found: Bug 1350804
Not same, thats for SVGs.

Comment 1

[Robert Utasi [:hunboy]]

Attachment: screencast of the bug happening in jsfiddle testcase

Comment 2

[Robert Utasi [:hunboy]]

Additional info: if you double-click on the frame to select (with blue painting) the image, it works ok

Comment 3

[Daniel Holbert [:dholbert] (PTO until 2/24)]

I can't reproduce any issues with images "blinking" locally, for what its worth. I tried the attached testcase as well as http://jsfiddle.net/utasir/7zn3feLs (the demo shown in the screencast). I tested using Nightly on Linux, as well as Firefox 64 on Windows 10 via BrowserStack.

I wonder if this might be a graphics driver bug?

Comment 4

[Daniel Holbert [:dholbert] (PTO until 2/24)]

Attachment: screencast of dholbert attempting & failing to reproduce the bug (in browserstack Win10+Firefox64)

For reference, here's a screencast of me trying to reproduce with BrowserStack "remote" windows 10 + Firefox 64. In the screencast, you can see my cursor moving around, and I'm intermittently clicking (on & near the image), but I can't reproduce any blinking-away issues.

Comment 5

[Daniel Holbert [:dholbert] (PTO until 2/24)]

hunboy, would you mind going to about:support and copypasting the "Graphics" section into a text file & posting that as an attachment here? [EDIT: never mind about this, comment 6 seems to be a better diagnostic]

There's a chance some graphics-knowledgeable folks (not me) might be able to glean some information about possible sources of trouble from that, or at least figure out correlations perhaps.

Comment 6

[Matt Woodrow (:mattwoodrow)]

I can reproduce this if I set accessibility.browsewithcaret=true, but not without (since there's nothing editable, and no caret).

Comment 7

[Robert Utasi [:hunboy]]

(In reply to Matt Woodrow (:mattwoodrow) from comment #6)

I can reproduce this if I set accessibility.browsewithcaret=true, but not without (since there's nothing editable, and no caret).

I can confirm this idea, when I turn it to false, the bug disappears.

Comment 8

[Robert Utasi [:hunboy]]

Attachment: graphics.txt in Hungarian language part from about:support

Comment 9

[Robert Utasi [:hunboy]]

Mozregression result:
with preference: accessibility.browsewithcaret=true

Last good: 2015-10-23
https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=0625c68c0abcfe4d10880d15d8fe7d06df3369c9&tochange=d53a52b39a95dced722cca90ac74529b66dd5253

First Bad: 2015-10-24
https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=0625c68c0abcfe4d10880d15d8fe7d06df3369c9&tochange=26078ba1c7be11cf46706216cad8603b92335cd0

Comment 10

[Daniel Holbert [:dholbert] (PTO until 2/24)]

Given the regression range (the smaller one in the lower link in comment 9): hunboy suggests (and I agree) that this seems likely to be a regression from bug 1214212:

e19090d182fa Thinker K.F. Li — Bug 1214212 - Remove clips from separator transform items. r=roc
https://hg.mozilla.org/mozilla-central/rev/e19090d182fa

--> marking as such

Comment 11

[Sotaro Ikeda [:sotaro]]

:miko, can you comment to the bug? Since you worked for css3d, thanks.

Comment 12

[Miko Mynttinen]

I think this problem is caused by caret item causing the content to be wrapped in nsDisplayWrapList, which causes us to create a transform separator1 for the transformed content.

Comment 13

[Miko Mynttinen]

Attachment: Bug 1518069 - Do not use transform separators for nsDisplayWrapList containing just nsDisplayTransform

Comment 14

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/ad20edb20e58
Do not use transform separators for nsDisplayWrapList containing just nsDisplayTransform r=mattwoodrow

Comment 15

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/ad20edb20e58

Comment 16

[Timea Cernea [:tbabos][inactive]]

Verified - Fixed on latest Nightly 66.0a1 (2019-01-28) (64-bit) on Windows 10, Ubuntu 16.04 and Mac OS 10.14.