+++ This bug was initially created as a clone of Bug #57481 +++
It seems old Extension:Renameuser didn't update ipb_address correctly, leaving many incorrect ipb_address values in database.
This also affects newly renamed users (due to job queue).
The method of trying to join user table is already used in revision table etc.
Version: 1.23.0
Severity: major
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=57481
https://bugzilla.wikimedia.org/show_bug.cgi?id=3279
Brion mentioned in bug 3279 that "the actual block works based on the user ID number" but it seems not the case (anymore?).
Searching for ipb_user in Block.php returns only one usage, in the function to insert new block rows.
Actually there're already reports from users saying that they're accidentially blocked, and the real cause is that they usurped an originally blocked user name in the past, and ipblocks table still stores the user name having been usurped because of (the broken-in-the-past and already-fixed) RenameUser extension.
Bumping severity because this causes legitimate users to be (at least practically) blocked.
(In reply to comment #3)
Sounds like bug 23135
Not really. This bug says "MediaWiki shouldn't be trapped by data messed up by Extension:Renameuser due to bug 23135".
Obsolete since such blocks will not be carried to new schema (see https://phabricator.wikimedia.org/source/mediawiki/browse/master/maintenance/migrateBlocks.php$96).