I've reported namespace changes in 2011 but it was in bugzilla and I don't remember the bug number, discussion on wiki is the following link: https://mzn.wikipedia.org/wiki/Project:Proposal_for_change_namespaces but a ZWNJ character in Project_talk is change to space, please fix it.
In 2011 a lot of page with prepending project name were missing after adding the project namespace so please make sure nothing will miss in this fix change.
An (extremely quick) search shows that it was T32752: Update namespaces for Mazandarani Wikipedia (mznwiki)
Is this a case of namespaceDupes?
there it is, thanks for the link.
yes, namespaceDupes, but I'm not sure how it works, see below for more details:
https://mzn.wikipedia.org/wiki/Special:PrefixIndex?prefix=ویکیپدیا_گپ:
(right namespace, we want this, already two pages exist in main namespace)
https://mzn.wikipedia.org/wiki/Special:PrefixIndex?prefix=ویکی_پدیا_گپ:
(wrong namespace, we don't want this, no pages exist)
The namespace first should be fixed in InitialiseSettings.php so don't change the title.
There must be a history of InitialiseSettings.php so should can check who changed it.
Change 184622 had a related patch set uploaded (by Mjbmr):
Fix project talk namespace for mznwiki T85383
reedy@tin:/srv/mediawiki-staging$ mwscript namespaceDupes.php mznwiki --fix ... 24583 (0,"ویکیپدیا_گپ:سفارتخنه") -> (5,"سفارتخنه") [[ویکیپدیا گپ:سفارتخنه]] ... resolving on page... ok. ... 6831 (0,"ویکیپدیا_گپ:پرچم_گپ") -> (5,"پرچم_گپ") [[ویکیپدیا گپ:پرچم گپ]] ... resolving on page... ok. Looks good! reedy@tin:/srv/mediawiki-staging$