Forum:WhatLinksHere .. what is correct behavior ?

I think most users would agree that Special:WhatLinksHere is a useful page to check before deleting a wiki article.
 * Does anyone check ...index.php?title=Special%3AWhatLinksHere&target=DELETED_PAGE after deleting a page?

Recently I have done exactly this because of a type of "Catch22" situation that can easily arise when using the Semantic MediaWiki extension.

What I find is that a ...index.php?title=Special%3AWhatLinksHere&target=DELETED_PAGE search returns the same results that were returned for the page just before it was deleted. Even though the articles listed in the results no longer link to the deleted page! i.e. no links - red or otherwise ... not even a matching word on the page!

Examples can be seen at:
 * http://vsk.wikia.com/index.php?title=Special%3AWhatLinksHere&target=junk7&namespace=
 * http://vsk.wikia.com/index.php?title=Special%3AWhatLinksHere&target=junk6&namespace=
 * http://vsk.wikia.com/index.php?title=Special%3AWhatLinksHere&target=junk5&namespace=
 * http://vsk.wikia.com/index.php?title=Special%3AWhatLinksHere&target=junk4&namespace=

No amount of page cache purging (&action=purge) or browser cache purging (Ctrl+Shift+R) will remedy the situation. I even tried the Special:SMWAdmin functions labeled:
 * Initialise or upgrade tables but this had no effect.
 * Data repair and upgrade but this takes forever to run. (If a Wikia staff member wants to investigate further you could accellerate completion of that process by invoking the MediaWiki maintenance script runJobs.php


 * So what's the connection with SMW? : With Semantic data it is possible to have a query at SurvivingPageA that lists, among other pages, UnwantedPageX. i.e. At SurvivingPageA a table of query results can be displaying links to intra-wiki pages and among those links is a link to UnwantedPageX.
 * Now if you delete UnwantedPageX then this semantic query no longer lists UnwantedPageX in the table of results - this makes perfect sense, right.
 * What makes no sense is that: ...index.php?title=Special%3AWhatLinksHere&target=UnwantedPageX&namespace= continues to list SurvivingPageA as a page that links to the now deleted UnwantedPageX. This is not intuitive. As demonstrated at the 4 examples above you can search each of the reported pages and find no link to any of the 4 deleted pages (i.e. junk4, .. ,junk7).

With that background in mind ... what does seem to remedy the error is a null edit i.e "edit/save with no changes" on the page that has the semantic query.
 * What confuses me about this remedy is that I had always believed that &action=purge is equivalent to (and even prefered over) a so-called null edit. Was I mistaken?

So the difficult questions (for me) to answer are:
 * 1) Is the WhatLinksHere search returning the correct result?
 * 2) * I think it is not.
 * 3) Is the error a MediaWiki bug with Special:WhatLinksHere or is it an SMW extension bug somehow connected to the query parser function #ask: ? not being evaluated upon &action=purge ?

If you can shed light on the matter I would appreciate it. --najevi 09:07, 22 August 2009 (UTC)