Bug T38358[1] points out that using a '#' character in input passed to ApiQueryBase::titlePartToKey() will silently truncate at the character before the '#', often generating incorrect results. With the merge of Gerrit change 191889,[2] passing a '#' into this method will now return an invalidtitle error, just as already happens when a title-part containing invalid characters such as '<' or '>' is passed in. The affected parameters include: * list=allpages apto, apfrom, and apprefix * list=alldeletedrevisions adrto, adrfrom, and adrprefix * list=deletedrevs drto, drfrom, and drprefix * list=filearchive fato, fafrom, and faprefix * list=allimages aito, aifrom, and aiprefix * list=alllinks alto, alfrom, and alprefix * list=alltransclusions atto, atfrom, and atprefix * list=allfileusages afto, affrom, and afprefix * list=allredirects arto, arfrom, and arprefix * list=allcategories acto, acfrom, and acprefix This should be deployed to WMF wikis with 1.25wmf19, see https://www.mediawiki.org/wiki/MediaWiki_1.25/Roadmap for the schedule. [1]: https://phabricator.wikimedia.org/T38358 [2]: https://gerrit.wikimedia.org/r/#/c/191889/ -- Brad Jorsch (Anomie) Software Engineer Wikimedia Foundation