This should only be done after 1.31.0-wmf.11 is deployed.
To fully resolve T9240: Usernames in history of imported pages should refer to original wiki and prepare for T167246: Refactor "user" & "user_text" fields into "actor" reference table, this maintenance script needs to be run to clean up existing imported rows and CentralAuth global blocks.
The script needs to be run twice for each wiki.
- With --table ipblocks --prefix meta to adjust CentralAuth global blocks. If for some reason $wgCentralAuthGlobalBlockInterwikiPrefix is changed, adjust the prefix according.
- With --assign --prefix imported --force to clean up old imports. Or of someone wants to give me a list of wiki language codes and short prefixes that mean more or less "imported", I could probably use that.