Btw., is it possible to get a date for when the change will take effect? If existing redirect pages have to be moved, it would be preferrable to do this right before the namespace alias comes into effect, to minimize the time of having non-working redirects.

Committed Gerrit Change I74421385 to implement this change.

Note: There are existing pages that start with this new namespace alias (see [[no:Special:PrefixIndex/WP:]]). The sysadmin in charge of pushing out this change needs to run namespaceDupes.php on nowiki in order to make existing redirects work properly.

Copying from what Reedy tried to do:

reedy@fenari:/home/wikipedia/common$ mwscript namespaceDupes.php nowiki --fix
... 332270 (0,"Wp:import") -> (4,"Import") [[Wikipedia:Import]]
... * cannot resolve automatically; page exists with ID 332271 *
... 26287 (0,"Wp:maler") -> (4,"Maler") [[Wikipedia:Maler]]
... * cannot resolve automatically; page exists with ID 3681 *
... 745287 (0,"Wp:sletting") -> (4,"Sletting") [[Wikipedia:Sletting]]
... * cannot resolve automatically; page exists with ID 775820 *
... 199921 (0,"Wp:stilguide") -> (4,"Stilguide") [[Wikipedia:Stilguide]]
... * cannot resolve automatically; page exists with ID 199925 *
... 199922 (0,"Wp:stilmanual") -> (4,"Stilmanual") [[Wikipedia:Stilmanual]]
... * cannot resolve automatically; page exists with ID 493993 *
... 330036 (0,"Wp:taksoboks") -> (4,"Taksoboks") [[Wikipedia:Taksoboks]]
... * cannot resolve automatically; page exists with ID 34688 *
... 332272 (0,"Wp:transwiki") -> (4,"Transwiki") [[Wikipedia:Transwiki]]
... * cannot resolve automatically; page exists with ID 166604 *
... 152436 (0,"WP:100000") -> (4,"100000") [[Wikipedia:100000]]
... * cannot resolve automatically; page exists with ID 135838 *
... 827332 (0,"WP:COMMONNAME") -> (4,"COMMONNAME") [[Wikipedia:COMMONNAME]]
... * cannot resolve automatically; page exists with ID 827334 *
... 533055 (0,"WP:Død_ekstern_lenker") -> (4,"Død_ekstern_lenker") [[Wikipedia:Død ekstern lenker]]
... * cannot resolve automatically; page exists with ID 903123 *
... 313975 (0,"WP:FAQ") -> (4,"FAQ") [[Wikipedia:FAQ]]
... * cannot resolve automatically; page exists with ID 68644 *
... 876672 (0,"WP:Fletting") -> (4,"Fletting") [[Wikipedia:Fletting]]
... * cannot resolve automatically; page exists with ID 876671 *
... 62646 (0,"WP:Hjelp") -> (4,"Hjelp") [[Wikipedia:Hjelp]]
... * cannot resolve automatically; page exists with ID 142841 *
... 160170 (0,"WP:IRC") -> (4,"IRC") [[Wikipedia:IRC]]
... * cannot resolve automatically; page exists with ID 166275 *
... 920170 (0,"WP:Kategori") -> (4,"Kategori") [[Wikipedia:Kategori]]
... * cannot resolve automatically; page exists with ID 17183 *
... 997177 (0,"WP:Logo") -> (4,"Logo") [[Wikipedia:Logo]]
... * cannot resolve automatically; page exists with ID 149874 *
... 1025456 (0,"WP:Maler") -> (4,"Maler") [[Wikipedia:Maler]]
... * cannot resolve automatically; page exists with ID 3681 *
... 232154 (0,"WP:NPOV") -> (4,"NPOV") [[Wikipedia:NPOV]]
... * cannot resolve automatically; page exists with ID 99168 *
... 30246 (0,"WP:O") -> (4,"O") [[Wikipedia:O]]
... * cannot resolve automatically; page exists with ID 173630 *
... 163380 (0,"WP:OSS") -> (4,"OSS") [[Wikipedia:OSS]]
... * cannot resolve automatically; page exists with ID 2192 *
... 770313 (0,"WP:OSS/bilder") -> (4,"OSS/bilder") [[Wikipedia:OSS/bilder]]
... * cannot resolve automatically; page exists with ID 301867 *
... 506785 (0,"WP:OTRS") -> (4,"OTRS") [[Wikipedia:OTRS]]
... * cannot resolve automatically; page exists with ID 166732 *
... 740978 (0,"WP:Objektivitet") -> (4,"Objektivitet") [[Wikipedia:Objektivitet]]
... * cannot resolve automatically; page exists with ID 9974 *
... 977680 (0,"WP:Oraklet") -> (4,"Oraklet") [[Wikipedia:Oraklet]]
... * cannot resolve automatically; page exists with ID 177866 *
... 232321 (0,"WP:Presse") -> (4,"Presse") [[Wikipedia:Presse]]
... * cannot resolve automatically; page exists with ID 34264 *
... 364212 (0,"WP:RENAME") -> (4,"RENAME") [[Wikipedia:RENAME]]
... * cannot resolve automatically; page exists with ID 521796 *
... 764323 (0,"WP:Sandkasse") -> (4,"Sandkasse") [[Wikipedia:Sandkasse]]
... * cannot resolve automatically; page exists with ID 699100 *
... 23049 (0,"WP:Slett") -> (4,"Slett") [[Wikipedia:Slett]]
... * cannot resolve automatically; page exists with ID 22993 *
... 168571 (0,"WP:Spøker") -> (4,"Spøker") [[Wikipedia:Spøker]]
... * cannot resolve automatically; page exists with ID 22982 *
... 50442 (0,"WP:T") -> (4,"T") [[Wikipedia:T]]
... * cannot resolve automatically; page exists with ID 432794 *
... 599149 (0,"WP:Tinget") -> (4,"Tinget") [[Wikipedia:Tinget]]
... * cannot resolve automatically; page exists with ID 1230 *
... 458895 (0,"WP:Torget") -> (4,"Torget") [[Wikipedia:Torget]]
... * cannot resolve automatically; page exists with ID 548007 *
... 29864 (0,"WP:WP") -> (4,"WP") [[Wikipedia:WP]]
... * cannot resolve automatically; page exists with ID 855323 *
... 432793 (0,"WP:t") -> (4,"T") [[Wikipedia:T]]
... * cannot resolve automatically; page exists with ID 432794 *
... 332695 (0,"WP:Ønskelisten") -> (4,"Ønskelisten") [[Wikipedia:Ønskelisten]]
... * cannot resolve automatically; page exists with ID 1389 *

Looks like we got things to work on before this change can really go deployed.

Retrying the change in case things got sorted out already. See change I285fe7c6.

In my previous comment, I asked for a date, but anyways, I've now moved/deleted the pages in the above log, so it should work now.

I have deployed the new change on the cluster. Two pages need to be fixed up:

$ mwscript namespaceDupes.php --wiki=nowiki --fix --suffix=/BROKEN
... 1091131 (0,"WP:HOTCAT") -> (4,"HOTCAT") [[Wikipedia:HOTCAT]]
... * cannot resolve automatically; page exists with ID 511122 *
... * old title HOTCAT
... * new title HOTCAT/BROKEN
... * using suffixed form [[Wikipedia:HOTCAT/BROKEN]] *
... resolving on page... ok.
... 1090514 (0,"WP:UK") -> (4,"UK") [[Wikipedia:UK]]
... * cannot resolve automatically; page exists with ID 702210 *
... * old title UK
... * new title UK/BROKEN
... * using suffixed form [[Wikipedia:UK/BROKEN]] *
... resolving on page... ok.

Oh noeees

Doesn't seem to be too big a problem, resolving this bug as fixed (since it has been deployed and works).