One more detail: If I edit the page with the incorrect (old) name and I save it, the showed name becomes the correct new one.

Hi @XanaG, thanks for taking the time to report this and welcome to Wikimedia Phabricator! Unfortunately this Wikimedia Phabricator task lacks some information. If you have time and can still reproduce the situation: Please add a more complete description to this task. That should include

• a clear list of exact steps to reproduce the situation, step by step, so that nobody needs to guess or interpret how you performed each step,
• what happens after performing these steps to reproduce,
• what you expected to happen instead,
• a full link to a web address where the issue can be seen.

You can edit the task description by clicking Edit Task. Ideally, a good description should allow any other person to follow these steps (without having to interpret steps) and see the same results. Problems that others can reproduce can get fixed faster. Thanks!

Go to
https://es.wikipedia.org/w/index.php?title=Usuaria:XanaG/Notas2
From the "Más" drop-down menu, select " Trasladar"
In the form, give Título nuevo: XanaG/Notas3
and click "Trasladar la página"
In the next page, where it says 'La página «Usuaria:XanaG/Notas2» ha sido trasladada a «Usuaria:XanaG/Notas3»', click on Usuaria:XanaG/Notas3
The page url is https://es.wikipedia.org/wiki/Usuaria:XanaG/Notas3
The displayed page title is Usuaria:XanaG/Notas2

The page url is https://es.wikipedia.org/wiki/Usuaria:XanaG/Notas3

That page never existed: https://es.wikipedia.org/w/index.php?title=Especial:Registro&page=Usuaria%3AXanaG%2FNotas3

So your steps to reproduce seem incorrect.

The displayed page title is Usuaria:XanaG/Notas2

I cannot reproduce the problem on https://www.mediawiki.org/wiki/User:AKlapper_(WMF)/Sandbox/T248789-02 after moving that page from https://www.mediawiki.org/wiki/User:AKlapper_(WMF)/Sandbox/T248789-01 - it shows the correct page title.

However, I see on https://es.wikipedia.org/w/index.php?title=Especial:Registro&page=Usuaria%3AXanaG%2FNotas1 that "XanaG trasladó la página Usuaria:XanaG/Notas1 a Usuaria:XanaG/Notas2" (moved page Usuaria:XanaG/Notas1 to Usuaria:XanaG/Notas2)
And you are right, https://es.wikipedia.org/w/index.php?title=Usuaria:XanaG/Notas2 has Usuaria:XanaG/Notas1 as its title.

Did you "Leave a redirect behind" ("Dejar una redirección"), or not?
Asking because of T246720#6008539 (but I don't understand on which wikis FlaggedRevs is deployed).

Hi,
Yes, https://es.wikipedia.org/wiki/Usuaria:XanaG/Notas3 does not exist on purpose. I thought that, if it did, you could not reproduce the problem exactly as I indicated, since you would then have to remove Notas3 to be able to move Notas2.

But yes, you can also see the problem in the pages registers.

In all cases I have seen, there was a redirect left behind. The redirect works fine. It does not make a difference whether one later deletes the redirected page or not.

The last significant (maybe helpful?) observation is that, if you edit the new page after moving it, the title will be correct. Ie, if you edit https://es.wikipedia.org/wiki/Usuaria:XanaG/Notas3 after doing the previous steps, and save the edit, the displayed title will be Usuaria:XanaG/Notas3 (matching the URL)

And,

Ah, that makes sense! Thanks for explaining and sorry that I got a bit confused at first. :)

Also seen on pl.wp when this page was moved: https://pl.wikipedia.org/w/index.php?title=Wikipedysta:Aleksander_Kadij/Cerkiew_w_Potoku_Górnym&action=history (it is now fixed after the page was edited)

I'm seeing this happen on MediaWiki.org, test.wikipedia.org, and the Icelandic Wikipedia, but not the English Wikipedia.

The cached page title is displayed both on the page itself and its talk page until the page is manually purged.

Another one from plwiki:
https://pl.wikipedia.org/wiki/Wikipedysta:Ateyshi/Teoria_j%C4%99zyk%C3%B3w_programowania

In T248789#6018288, @Aklapper wrote:

Adding CPT Clinic Duty. (If this is not the right CPT tag, then please edit the quite short tag description what people are supposed to tag.)

It's not, tasks should go into the inbox column on Platform Engineering. I've edited the tag description to specify that.

Change 585532 had a related patch set uploaded (by Anomie; owner: Anomie):
[mediawiki/core@master] MovePage: Use correct Title when creating the null revision

https://gerrit.wikimedia.org/r/585532

Change 585532 merged by jenkins-bot:
[mediawiki/core@master] MovePage: Use correct Title when creating the null revision

https://gerrit.wikimedia.org/r/585532

Should we back-port?

This is currently marked "UBN!", so that would suggest yes. This bug seems to exist in both wmf.25 and wmf.26.

In T248789#6023439, @Anomie wrote:

This is currently marked "UBN!", so that would suggest yes.

That is correct. Hence my question implicitly being "do people really think this is UBN?".

Change 585578 had a related patch set uploaded (by Jforrester; owner: Anomie):
[mediawiki/core@wmf/1.35.0-wmf.26] MovePage: Use correct Title when creating the null revision

https://gerrit.wikimedia.org/r/585578

Change 585578 merged by jenkins-bot:
[mediawiki/core@wmf/1.35.0-wmf.26] MovePage: Use correct Title when creating the null revision

https://gerrit.wikimedia.org/r/585578

Mentioned in SAL (#wikimedia-operations) [2020-04-02T19:35:27Z] <jforrester@deploy1001> Synchronized php-1.35.0-wmf.26/includes/MovePage.php: T248789 MovePage: Use correct Title when creating the null revision (duration: 00m 59s)