Extension:Auto Create Category Pages

Auto Create Category Pages (what a mouthful!) automatically creates stub pages for non-existent categories as soon as they are linked to, avoiding the confusing default behavior of "There is currently no text in this page..." or redirecting to the edit page.

Configuration
Auto Create Category Pages has the following 3 messages in the Mediawiki namespace, which can be changed to accommodate your preferences:

The text of 'autocreatecategorypages-stub' can also be overridden using $wgAutoCreateCategoryStub, which  can contain wikitext as well.

MediaWiki compatibility
Version 1.0.0 and above only works with MediaWiki 1.25.0+. The previous version should work with MediaWiki 1.21-1.24.

Caveats
This extension is currently not recommended for use on large wikis, as it doesn't implement any caching of its database queries (for retrieving the list of existing category pages).

Credits
Auto Create Category Pages was originally created as "Uniwiki Auto Create Category Pages" by Merrick Schaefer, Mark Johnston, Evan Wheeler & Adam Mckaig, as part of the Uniwiki project for UNICEF (see Category:Uniwiki).

As Uniwiki extensions for MediaWiki are not maintained by the original developers anymore, according to an e-mail by Mark Johnston from Nov 9, 2012, the maintenance of this one extension was taken up by Dror S. [FFS].

Changelog

 * Version 1.0.2, 2017-03-25: A much improved query of pre-existing categories, by Brent Laabs (labster)
 * Version 1.0.1, 2016-02-01: Fix bug where only the first new category page was actually created
 * Version 1.0.0, 2015-05-24: Convert to extension registration for MW 1.25
 * Version 0.2.0, 2013-10-28: updated to work with MW 1.21.x & MW 1.22alpha.
 * Version 0.1.0, 2008-08-01: original release.