[Mediawiki-l] where replace MW "_" with " " ? Usernameproblem

[Jens]

Hi,

we are using a MW with an OP3 authentication.It works without problem with
names like hexxer or testuser, but witk names like "test_user" it dont work.
Failuremessage show us that MW replace the _ with an space. t means it will
authenticate not "test_user" MW change it to "test user".

Anybody now in which file we have to change it?

regards and thanks