If you create a namespace "Foo", and the wiki already has articles whose title begins with "Foo_:_", those articles become inaccessible. To reproduce:
- Create an article named "Foo : Bar" (with spaces around the colon) or "Foo_:_Bar" (with underscores around the colon) on a wiki that does not have a "Foo" namespace.
- Next, create a "Foo" namespace in LocalSettings.php: $wgExtraNamespaces = 'Foo';
- Try to hit the original article. It is impossible. The spaces get removed, and you are redirected to "Foo:Bar" (no spaces). The original article is inaccessible.
This is on MediaWiki 1.27.1 running on Ubuntu 16.04.1 LTS. CirrusSearch version is 0.2. PHP version is:
$ php --version PHP 7.0.8-0ubuntu0.16.04.3 (cli) ( NTS ) Copyright (c) 1997-2016 The PHP Group Zend Engine v3.0.0, Copyright (c) 1998-2016 Zend Technologies with Zend OPcache v7.0.8-0ubuntu0.16.04.3, Copyright (c) 1999-2016, by Zend Technologies with Xdebug v2.4.0, Copyright (c) 2002-2016, by Derick Rethans