1986587 - Layout disorder when moving active tab in collapsed group with other tabs

Status: VERIFIED FIXED

(Firefox :: Tabbed Browser, defect, P2)

Description

[Merci chao]

Steps to reproduce:

1. Select a tab in a tab group, then collapse the group ([hasactivetab][collapsed]);
2. Press Ctrl to select other tabs;
3. Click on the active tab in group, drag around, an empty space is left in the tab strip (which shouldn't);
4. Drop, the transform isn't removed from the dragged tabs (which shouldn't).

Actual results:

Like the steps said.

Expected results:

Not allowing to move the active tab with external tabs, or handle the behavior well.

Comment 1

[Merci chao]

Attachment: record.mp4

Comment 2

[Merci chao]

Attachment: record2.mp4

Comment 3

[Monica Chiorean]

Marking issue as New as I was able to reproduce it on Win11x64 using FF build 144.0a1(20250905010130) and steps from description.

Comment 4

[DJ (:dwalker) (on PTO until Apr 7)]

Attachment: Bug 1986587 - Ensure multiselected tabs in collapsed groups remain visible. r?sthompson

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/a3ba6e7998da
https://hg.mozilla.org/integration/autoland/rev/0a9297d3e8f5
Ensure multiselected tabs in collapsed groups remain visible. r=sthompson,tabbrowser-reviewers

Comment 6

[Phabricator Automation]

firefox-beta Uplift Approval Request

• User impact if declined: Users may experience glitches when dragging multiselected tabs, if one of those tabs is in a collapsed group
• Code covered by automated testing: no
• Fix verified in Nightly: no
• Needs manual QE test: yes
• Steps to reproduce for manual QE testing: 1. create a tab group with multiple tabs

2. create a new tab outside of the group
3. select a grouped tab and collapse the group. The selected tab will remain visible
4. perform a multiselection to select both the grouped tab and the ungrouped tab
5. drag either of the selected tabs to reposition the multiselection on the tabstrip.

Without the patch applied, visual glitches occur. Initiating drag from the ungrouped tab will keep the grouped tab trapped in the group. With the patch applied, dragging the multiselected group works normally.

• Risk associated with taking this patch: low
• Explanation of risk level: Small in size and scope, changes visibility calculation for multiselected tabs in tab groups
• String changes made/needed: N/A
• Is Android affected?: no

Comment 7

[DJ (:dwalker) (on PTO until Apr 7)]

Attachment: Bug 1986587 - Ensure multiselected tabs in collapsed groups remain visible. r?sthompson

Original Revision: https://phabricator.services.mozilla.com/D270057

Comment 8

[pstanciu]

https://hg.mozilla.org/mozilla-central/rev/0a9297d3e8f5

Comment 9

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

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

Comment 10

[Pulsebot]

https://github.com/mozilla-firefox/firefox/commit/13efb176efb6
https://hg.mozilla.org/releases/mozilla-beta/rev/18c13b88a30b

Comment 11

[Monica Chiorean]

Verified on Win11x64 using FF build 146.0a1(20251030094725), that there is no gap after dropping the tabs.
Waiting for 145.0 build to check there.

Merci chao, does the issue still reproduce on your end on latest nightly? Thank you.

Comment 12

[Merci chao]

(In reply to Monica Chiorean from comment #11)

Verified on Win11x64 using FF build 146.0a1(20251030094725), that there is no gap after dropping the tabs.
Waiting for 145.0 build to check there.

Merci chao, does the issue still reproduce on your end on latest nightly? Thank you.

The issue has been resolved, but letting the multiselected tabs visible in group introduces a new issue, though it's more acceptable.

Comment 13

[Merci chao]

Attachment: record.mp4

Comment 14

[Stephen Thompson [:sthompson]]

Thanks for trying it out, Merci chao! I filed bug 1997587 to capture this bug.

Comment 15

[Monica Chiorean]

Verified on Win11x64 using FF build 145.0b9.