See rMW includes/auth/TemporaryPasswordPrimaryAuthenticationProvider.php (Line 487)
$url omits the URL protocol (http or https) because it uses getFullURL(); resulting in //lang.wikiproject.org/etc-type URLs.
I guess it needs to be changed to getCanonicalURL() instead.
This confused me, so tested it
However, if you did not generate this request and want to prevent unsolicited emails, you may want to update your email options at <//en.wikipedia.org/wiki/Special:Preferences#mw-prefsection-personal-email>. You can require both username and email address to generate password reset emails. This may reduce the number of such incidents.
The link at the start is fine
Someone (probably you, from IP address <REDACTED>) requested a reset of your password for Wikipedia (<https://en.wikipedia.org/wiki/Main_Page>). The following user account is associated with this email address:
Caused by T233969: Update Temporary Password Email with Preference Info [x-small], rMWd1604f7445c1: Mention requiring email address in password reset emails by @MaxSem
Change 651678 had a related patch set uploaded (by Reedy; owner: Reedy):
[mediawiki/core@master] Fix display of Special:Preferences url in password reset email
Change 651603 had a related patch set uploaded (by Reedy; owner: Reedy):
[mediawiki/core@REL1_35] Fix display of Special:Preferences url in password reset email
And for confirmation
reedy@deploy1001:~$ mwscript eval.php enwiki > var_dump( SpecialPage::getTitleFor( 'Preferences', false, 'mw-prefsection-personal-email' )->getFullURL(), SpecialPage::getTitleFor( 'Preferences', false, 'mw-prefsection-personal-email' )->getCanonicalURL() ); string(73) "//en.wikipedia.org/wiki/Special:Preferences#mw-prefsection-personal-email" string(79) "https://en.wikipedia.org/wiki/Special:Preferences#mw-prefsection-personal-email"
Change 651678 merged by jenkins-bot:
[mediawiki/core@master] Fix display of Special:Preferences url in password reset email
Change 651603 merged by jenkins-bot:
[mediawiki/core@REL1_35] Fix display of Special:Preferences url in password reset email