Extension:QrCode/Impersonation

= problem description = 1. QrCodes are generated for pages that do not have or transclude a function call, in this case properties [2,3,4].

2. These uploaded files have properties [5] and they belong to a category, which means they get linked in the categorylinks table. A common result of this is that qrcode images turn up in i.e. semantic queries [9,10].

3. Qrcodes are even generated for existing qrcodes [6,7]. One way to trigger than behaviour is to visit a File's page and click on the Delete link, without actually deleting the file. This leads to situations such as [8].

4. The files get linked from several pages as this example shows [11]. None of the pages said to link to the file actually do include that file, also those pages vary (2 days ago, 14 pages linked, today only 7 link)

5. Browsing the properties of the above file [12], you can see that it got somehow mixed up with a completely different event.

[0] http://www.mediawiki.org/wiki/Extension:QrCode [1] http://svn.wikimedia.org/doc/classLocalFile.html#4b626952ae0390a7fa453a4bfece8252 [2] https://www.hackerspace.lu/wiki/File:QR-Is_U19.png [3] https://www.hackerspace.lu/wiki/File:QR-Has_SingleIssuePrice.png [4] https://www.hackerspace.lu/wiki/File:QR-Has_Issues.png [5] https://www.hackerspace.lu/wiki/Property:Has_SingleIssuePrice [6] https://www.hackerspace.lu/wiki/File:QR-QR-Location.png.png [7] https://www.hackerspace.lu/w/index.php?title=Special:RecentChanges&hidebots=0 [8] https://www.hackerspace.lu/wiki/File:QR-QR-QR-QR-Location.png.png.png.png [9] https://www.hackerspace.lu/wiki/Projects#Concluded_Projects [10] https://www.hackerspace.lu/wiki/Special:BrowseData#Q [11] https://www.hackerspace.lu/wiki/File:QR-Syn2cat.png [12] https://www.hackerspace.lu/wiki/Special:Browse/File:QR-2DSyn2cat.png

= possible causes = It's possible that the internal uploading process interferes with global parsing state when it generates and saves the description page for the wiki; if so, fixing that may require jumping through some interesting hoops. :)

-- brion