1899556 - Tab hover preview leaks for a moment over an app that is in focus even though Firefox is in background

Status: VERIFIED FIXED

(Firefox :: Tabbed Browser, defect, P2)

Description

[Bogdan Maris, Desktop Test Engineering]

Attachment: Screencast showing the issue

Found in

• Nightly 128.0a1

Affected versions

• Nightly 128.0a1

Tested platforms

• Affected platforms: MacOS 13
• Unaffected platforms: Windows 11 and Ubuntu 22.04

Preconditions

• browser.tabs.cardPreview.enabled to true

Steps to reproduce

1. Open a few different websites in different tabs
2. Focus a different app but make sure to have the Firefox tabstrip in view
3. Hover over some tabs from Firefox and quickly move to the app in view or apple menu bar

Expected result

• Tab preview is not leaking over the app in focus.

Actual result

• Tab preview is leaking for a moment over the app that is in focus.

Regression range

• Very hard to find a regression for this one since on older builds it happens very intermittently and on some the Firefox window stole the focus entirely.

Comment 1

[Chris Peterson [:cpeterson]]

P2 because James thinks this is worth investigating soon.

Comment 2

[Jeremy Swinarton]

Attachment: Bug 1899556: Disable THP when app in background r?dwalker

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/53ba7eb70229
Disable THP when app in background r=dwalker,tabbrowser-reviewers,mak

Comment 4

[Norisz Fay [:noriszfay]]

https://hg.mozilla.org/mozilla-central/rev/53ba7eb70229

Comment 5

[BugBot [:suhaib / :marco/ :calixte]]

Since nightly and release are affected, beta will likely be affected too.
For more information, please visit BugBot documentation.

Comment 6

[Bogdan Maris, Desktop Test Engineering]

Looks good to me using latest Nightly 130.0a1 on macOS 13.6.

Comment 7

[Donal Meehan [:dmeehan]]

:cpeterson, I set this as disabled since browser.tabs.cardPreview.enabled is nightly only, though there is an experiment controlling that pref.
Was this something you were looking to uplift? This also caused a perma test failure regression for when it hits beta.

Comment 8

[Chris Peterson [:cpeterson]]

We'd like to uplift this fix to Beta 129, though we'll also need to fix (and uplift) the beta test failure in bug 1907717.

Tab Hover Preview is enabled for 100% of Beta 129 using Nimbus and we plan to enable it for 100% of Fx 129 Release using Nimbus, too. I'll file a bug to enable the browser.tabs.hoverPreview.enabled pref by default (in 130).

Comment 9

[Chris Peterson [:cpeterson]]

Too risky to uplift to Beta 129.