Last modified: 2011-02-13 21:20:21 UTC
If Special:Listfiles/$par is called, the user selector doesn't work because it sets a hidden title field to Special:Listfiles/$par and a hidden user field to an empty string.
This also happened without the $par -- any time that initial values had been set, it would double in the hidden field. When the user field was added in r68096, it was added to the hidden-field blacklist in the pager's extended form, but with the wrong name. Fixing from 'username' to 'user' gets it working; done on trunk in r82081.