1930056 - Tabstrip height changes when closing multiple tabs

Status: VERIFIED FIXED

(Toolkit :: UI Widgets, defect)

Description

[6k64x4ma]

Attachment: AGDRec.mp4

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:133.0) Gecko/20100101 Firefox/133.0

Steps to reproduce:

1. Set ui.prefersReducedMotion to 1 (reduced motion).
2. Pin any tab.
3. Open about:about and duplicate tab until the scroller appears.
   (I have seen the issue with random pages other than about:about, but it seems to happen more frequently with about: pages.)
4. Select the pinned tab.
5. Right-click the pinned tab > Close Multiple Tabs > Close Tabs to Right or Close Other Tabs.

Actual results:

• Sometimes tabstrip height changes and the content moves up and down.

Expected results:

• Tabstrip height doesn't change.

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=773aed942ff98525ee9bc2c03fd96dbd6c0eee96&tochange=9d4782d16aacb9b51e440042a677f6c5c68a0ca9

Comment 1

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

:emilio, since you are the author of the regressor, bug 1913322, could you take a look? Also, could you set the severity field?

For more information, please visit BugBot documentation.

Comment 2

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1930056 - Avoid empty tabstrip from shrinking. r=#tabbrowser-reviewers

In the situation in comment 0, the pinned tabs are absolutely positioned
until we recompute the position / fire the overflow event, which now
fires later. Thus, for a frame, we might have an "empty" tabstrip.

Fix this by ensuring that the tabstrip doesn't shrink under the minimum
height.

Rework a bit the variables to avoid repeating the math a third time.

Comment 3

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

Set release status flags based on info from the regressing bug 1913322

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/138d80ec44f8
Avoid empty tabstrip from shrinking. r=tabbrowser-reviewers,desktop-theme-reviewers,dao

Comment 5

[agoloman]

https://hg.mozilla.org/mozilla-central/rev/138d80ec44f8

Comment 6

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

The patch landed in nightly and beta is affected.
:emilio, is this bug important enough to require an uplift?

• If yes, please nominate the patch for beta approval.
• If no, please set status-firefox133 to wontfix.

For more information, please visit BugBot documentation.

Comment 7

[Emilio Cobos Álvarez (:emilio)]

Comment on attachment 9436469 [details]
Bug 1930056 - Avoid empty tabstrip from shrinking. r=#tabbrowser-reviewers

Beta/Release Uplift Approval Request

• User impact if declined/Reason for urgency: Trivial css regression fix
• Is this code covered by automated tests?: No
• Has the fix been verified in Nightly?: Yes
• Needs manual test from QE?: Yes
• If yes, steps to reproduce: comment 0
• List of other uplifts needed: none
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): Trivial
• String changes made/needed: none
• Is Android affected?: No

Comment 8

[Donal Meehan [:dmeehan]]

Comment on attachment 9436469 [details]
Bug 1930056 - Avoid empty tabstrip from shrinking. r=#tabbrowser-reviewers

Approved for 133.0b8

Comment 9

[Pulsebot]

https://hg.mozilla.org/releases/mozilla-beta/rev/8a65bce7aa40

Comment 10

[Peter Magyari (Desktop QA)]

Verified fixed on Nightly 134.0a1 (20241112093250) and Beta 133.0b8 (20241111165552)