In some cases special characters stored in properties with datatype URL get erroneously transformed causing the link not to work, e.g.
[[Has URL::https://gerrit.wikimedia.org/r/gitweb?p=mediawiki/extensions/TitleKey.git;a=tree]]
->
https://gerrit.wikimedia.org/r/gitweb?p=mediawiki/extensions/TitleKey.git%3Ba=tree
See here for a live example:
http://scratchpad.referata.com/wiki/Datatype_URL_-_test
Version: unspecified
Severity: major