Reproducible on trunk only, 1.18 is ok. Steps to reproduce:
- Open Special:ListUsers/sysop: http://en.wikipedia.beta.wmflabs.org/wiki/Special:ListUsers/sysop
- Select another group from the dropdown, submit the form.
Expected result: The members of the new group are shown.
Actual result: The URL becomes something like
http://en.wikipedia.beta.wmflabs.org/w/index.php?title=Special%3AListUsers%2Fsysop&username=&group=bureaucrat&limit=50
and the /sysop overrides the &group=bureaucrat
Version: 1.20.x
Severity: normal
URL: http://en.wikipedia.beta.wmflabs.org/wiki/Special:ListUsers/sysop