== The problem ==
While developing a bot I've just figure out that a query on the [transcludedin](https://www.mediawiki.org/wiki/API:Transcludedin) generator with a non-numeric `gtinamespace` throws an error 500 but only after 60 seconds of execution.
== Proof of concept ==
* https://en.wikipedia.org/w/api.php?action=query&titles=A&generator=transcludedin>inamespace=Test
* https://it.wikipedia.org/w/api.php?action=query&titles=A&generator=transcludedin>inamespace=Test
== Normal usage examples ==
* https://en.wikipedia.org/w/api.php?action=query&titles=A&generator=transcludedin>inamespace=0
* https://it.wikipedia.org/w/api.php?action=query&titles=A&generator=transcludedin>inamespace=0
== Notes ==
As far I can see the `transcludedin` module through a `list` is not affected.
Also this is not a problem related to all the generators with a namespace filter e.g. `allpages` quits immediately as expected:
* https://en.wikipedia.org/w/api.php?action=query&titles=A&generator=allpages&gapnamespace=Test
Here some MediaWiki versions that I think are **not** affected:
* <=1.24 (has not transcludedin generator)
* 1.27.4
* 1.29.1
Now I really have no time to further investigate because tomorrow morning I'm in an office.
== Definition ==
* `includes/api/ApiQueryBacklinksprop.php`