I was just about to file the same ticket ;)

Change 868881 had a related patch set uploaded (by Lectrician1; author: Lectrician1):

[mediawiki/skins/Vector@master] Fix page title from overflowing

https://gerrit.wikimedia.org/r/868881

Test wiki created on Patch demo by TheDJ using patch(es) linked to this task:
https://patchdemo.wmflabs.org/wikis/d7e4e189a6/wiki/AS1f000S11a20S19220S1ce20S1ce20S19220S1fb20S11502M518x603S1f000483x398S11a20497x417S19220497x451S1ce20496x474S1ce20496x508S19220497x542S1fb20497x565S11502482x588

https://patchdemo.wmflabs.org/wikis/d7e4e189a6/wiki/AS1f000S11a20S19220S1ce20S1ce20S19220S1fb20S11502M518x603S1f000483x398S11a20497x417S19220497x451S1ce20496x474S1ce20496x508S19220497x542S1fb20497x565S11502482x588?useskin=vector-2022

from:

That looks good in Vector-2022, but the titles are still overflowing in Vector and Monobook:

• https://patchdemo.wmflabs.org/wikis/d7e4e189a6/wiki/AS1f000S11a20S19220S1ce20S1ce20S19220S1fb20S11502M518x603S1f000483x398S11a20497x417S19220497x451S1ce20496x474S1ce20496x508S19220497x542S1fb20497x565S11502482x588?useskin=vector
• https://patchdemo.wmflabs.org/wikis/d7e4e189a6/wiki/AS1f000S11a20S19220S1ce20S1ce20S19220S1fb20S11502M518x603S1f000483x398S11a20497x417S19220497x451S1ce20496x474S1ce20496x508S19220497x542S1fb20497x565S11502482x588?useskin=monobook

In T319052#8480948, @jhsoby wrote:

That looks good in Vector-2022, but the titles are still overflowing in Vector and Monobook:

• https://patchdemo.wmflabs.org/wikis/d7e4e189a6/wiki/AS1f000S11a20S19220S1ce20S1ce20S19220S1fb20S11502M518x603S1f000483x398S11a20497x417S19220497x451S1ce20496x474S1ce20496x508S19220497x542S1fb20497x565S11502482x588?useskin=vector
• https://patchdemo.wmflabs.org/wikis/d7e4e189a6/wiki/AS1f000S11a20S19220S1ce20S1ce20S19220S1fb20S11502M518x603S1f000483x398S11a20497x417S19220497x451S1ce20496x474S1ce20496x508S19220497x542S1fb20497x565S11502482x588?useskin=monobook

Bot those are
1: not really responsive skins and already overflow the viewport for content
2: they don't restrict their content width, like vector-2022 does
3: overflow on the right side of the viewport, instead of on the left side like vector 2022 does.

I'm not against fixing legacy vector and monobook in this ticket as well, but I do think those should be separate patches.

There was another task lying around for very-long page titles that I remember seeing @alexhollender_WMF put some display suggestions on. Not to prevent this task from moving forward; something is better than nothing IMO.

One note, is that there is a process going on to change the html structure of headings, see T13555. We probably don't want to conflict with those cache sensitive changes.

In T319052#8481650, @TheDJ wrote:

I'm not against fixing legacy vector and monobook in this ticket as well, but I do think those should be separate patches.

Yeah, that's reasonable. 👍

In T319052#8482879, @Izno wrote:

There was another task lying around for very-long page titles that I remember seeing @alexhollender_WMF put some display suggestions on. Not to prevent this task from moving forward; something is better than nothing IMO.

hm, trying to remember. I know we did this one T323177: Page titlebar elements are vertically centered when the page title wraps, though it sounds like there might be another I'm forgetting about.

I was thinking of T298885: [Sticky header] Consider removing (or increasing) max-width on page title it looks like.

Change 868881 merged by jenkins-bot:

[mediawiki/skins/Vector@master] Fix page title from overflowing

https://gerrit.wikimedia.org/r/868881

Test wiki on Patch demo by TheDJ using patch(es) linked to this task was deleted:

https://patchdemo.wmflabs.org/wikis/d7e4e189a6/w/