Vector TOC in Sticky header is styled incorrectly and empty when changing viewports
Closed, ResolvedPublic3 Estimated Story PointsBUG REPORT
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Authored By

	bwang
	Jan 19 2026, 7:12 PM

Description

Steps to replicate the issue (include links if applicable):

Log into Vector
Visit https://en.wikipedia.org/wiki/Initial_campaign_of_the_Breton_Civil_War on a large screen with the table of contents in the left sidebar by default (refresh page after correcting if not present)
Scroll down to show the sticky header
Move the TOC to the sticky header by pressing the "hide" button in the TOC
Note: the incorrect spacing:
Decrease the viewport so that the sticky header disappears
Increase the viewport so the sticky header is back
Click the TOC button to see the TOC doesnt work

What happens?:

Screenshot 2026-01-19 at 2.04.04 PM.png (148×310 px, 14 KB)

Screen Recording 2026-01-19 at 2.04.20 PM.mov3 MBDownload

What should have happened instead?:

The TOC should still work after changing viewports
A fix should not cause T415932: [regression] Page title in Vector 2022 sticky header displays in mixed fonts and with weird spacing around the colon on non-main namespaces on non-article namespaces

Software version (on Special:Version page; skip for WMF-hosted wikis like Wikipedia):
In production on english wiki

Other information (browser name/version, screenshots, etc.):

Details

Related Changes in Gerrit:

Subject	Repo	Branch	Lines +/-
Fix sticky header TOC spacing and overflow	mediawiki/skins/Vector	master	+12 -3
Fix sticky header TOC spacing and TOC disappearing on viewport change	mediawiki/skins/Vector	master	+26 -20
Fix sticky header TOC spacing and TOC disappearing on viewport change	mediawiki/skins/Vector	master	+33 -27

Customize query in gerrit

Related Objects

Mentioned In: T415932: [regression] Page title in Vector 2022 sticky header displays in mixed fonts and with weird spacing around the colon on non-main namespaces
Mentioned Here: T349436: Kerns are clipped from sides of sticky header title
T415932: [regression] Page title in Vector 2022 sticky header displays in mixed fonts and with weird spacing around the colon on non-main namespaces

Event Timeline

bwang created this task.Jan 19 2026, 7:12 PM

Restricted Application added a subscriber: Aklapper. · View Herald TranscriptJan 19 2026, 7:12 PM

bwang triaged this task as High priority.Jan 19 2026, 7:13 PM

the spacing bug was caused by this: https://gerrit.wikimedia.org/r/c/mediawiki/skins/Vector/+/1220395

Change #1229147 had a related patch set uploaded (by Bernard Wang; author: Bernard Wang):

[mediawiki/skins/Vector@master] Fix sticky header toc spacing

https://gerrit.wikimedia.org/r/1229147

gerritbot added a project: Patch-For-Review.Jan 20 2026, 8:05 PM

Jdlrobson-WMF updated the task description. (Show Details)Jan 23 2026, 5:22 PM

Change #1229147 merged by jenkins-bot:

[mediawiki/skins/Vector@master] Fix sticky header TOC spacing and TOC disappearing on viewport change

https://gerrit.wikimedia.org/r/1229147

Maintenance_bot removed a project: Patch-For-Review.Jan 23 2026, 6:31 PM

bwang moved this task from Incoming to Ready for sprint on the Reader Experience Team board.Jan 27 2026, 6:19 PM

bwang moved this task from Ready for sprint to REx Sprint 13 [Q3 Jan 27 - Feb 9] on the Reader Experience Team board.

bwang edited projects, added Reader Experience Team (REx Sprint 13 [Q3 Jan 27 - Feb 9]); removed Reader Experience Team.

Sneha lowered the priority of this task from High to Medium.Jan 27 2026, 6:29 PM

bwang moved this task from Ready to Needs QA on the Reader Experience Team (REx Sprint 13 [Q3 Jan 27 - Feb 9]) board.Jan 27 2026, 6:38 PM

Checked on cawiki wmf.13 and hewiki wmf.13 - the fix for the spacing is in place.

The second issue - the empty TOC after changing the width of the viewport is not reproducible on on wmf.13.
Waiting for enwiki wmf.13 to confirm that the original issue is fixed.

Patch is being reverted so moving back to "Ready"

Per async estimation.

Jdlrobson-WMF updated the task description. (Show Details)Feb 2 2026, 4:56 PM

Change #1235845 had a related patch set uploaded (by Bernard Wang; author: Bernard Wang):

[mediawiki/skins/Vector@master] Fix sticky header TOC spacing and TOC disappearing on viewport change

https://gerrit.wikimedia.org/r/1235845

gerritbot added a project: Patch-For-Review.Feb 2 2026, 5:29 PM

Change #1235845 merged by jenkins-bot:

[mediawiki/skins/Vector@master] Fix sticky header TOC spacing and TOC disappearing on viewport change

https://gerrit.wikimedia.org/r/1235845

Maintenance_bot removed a project: Patch-For-Review.Feb 2 2026, 9:31 PM

Jdlrobson-WMF moved this task from Ready to Needs QA on the Reader Experience Team (REx Sprint 13 [Q3 Jan 27 - Feb 9]) board.Feb 2 2026, 9:31 PM

ReleaseTaggerBot added a project: MW-1.46-notes (1.46.0-wmf.14; 2026-02-03).Feb 2 2026, 10:00 PM

I wasn't fast enough to comment on Gerrit before the patch was approved. The new patch causes a regression in T349436: Kerns are clipped from sides of sticky header title.

The overhang on the right side of italic f is clipped (only left side is still correct):

Long page titles now overlap the rest of the sticky header:

Compare to the desired rendering in my screenshots at T349436#11482237.

Change #1236781 had a related patch set uploaded (by Bernard Wang; author: Bernard Wang):

[mediawiki/skins/Vector@master] Fix sticky header TOC spacing and overflow

https://gerrit.wikimedia.org/r/1236781

gerritbot added a project: Patch-For-Review.Feb 4 2026, 4:44 PM

@matmarex thank you for the catch! i put up a small fix here: https://gerrit.wikimedia.org/r/c/mediawiki/skins/Vector/+/1236781

Change #1236781 merged by jenkins-bot:

[mediawiki/skins/Vector@master] Fix sticky header TOC spacing and overflow

https://gerrit.wikimedia.org/r/1236781

Maintenance_bot removed a project: Patch-For-Review.Feb 5 2026, 9:30 PM

Jdlrobson-WMF assigned this task to Etonkovidova.Feb 12 2026, 7:50 PM

Etonkovidova mentioned this in T415932: [regression] Page title in Vector 2022 sticky header displays in mixed fonts and with weird spacing around the colon on non-main namespaces.Sun, Feb 15, 9:37 PM

Etonkovidova updated the task description. (Show Details)

Checked on enwiki wmf.15

the long title mentioned in https://phabricator.wikimedia.org/T414993#11580450 Lopadotemachoselachogaleokranioleipsanodrimhypotrimmatosilphiokarabomelito...

before the fix	after the fix

Screenshot 2026-02-15 at 4.59.40 PM.png (449×1 px, 131 KB)

HFan-WMF closed this task as Resolved.Thu, Feb 19, 5:11 PM

	F72117479: Screenshot 2026-02-15 at 4.59.40 PM.png
	Sun, Feb 15, 10:03 PM

	F72117258: Screenshot 2026-02-15 at 4.39.38 PM.png
	Sun, Feb 15, 10:03 PM

	F72117472: Screenshot 2026-02-06 at 4.47.43 PM.png
	Sun, Feb 15, 10:03 PM

	F71621474: Screenshot 2026-01-28 at 6.31.23 PM.png
	Jan 28 2026, 11:34 PM

	F71621477: Screenshot 2026-01-28 at 6.28.00 PM.png
	Jan 28 2026, 11:34 PM

	F71597931: Screenshot 2026-01-23 at 12.22.16 PM.png
	Jan 23 2026, 5:22 PM

	F71660790: image.png
	Feb 3 2026, 7:24 PM

	F71660785: image.png
	Feb 3 2026, 7:24 PM

Vector TOC in Sticky header is styled incorrectly and empty when changing viewportsClosed, ResolvedPublic3 Estimated Story PointsBUG REPORTActions

Description

Details

Related Objects

Event Timeline

Vector TOC in Sticky header is styled incorrectly and empty when changing viewports
Closed, ResolvedPublic3 Estimated Story PointsBUG REPORT
Actions