Usernames are transformed into Title objects as part of the signon process. I presume this is to ensure that "User:username" makes a valid page title.

As part of that process, it appears to me from ll. 1276-1279 in Title.php that leading and trailing underscores are prevented from being in MediaWiki usernames:

# Clean up whitespace # $t = preg_replace( '/[ _]+/', '_', $this->mDbkeyform ); $t = trim( $t, '_' );

We are doing authentication via an external university-wide Active Directory system. Though we now do not permit new usernames which begin with "_", there are 2 legacy names which do. We also have 38 usernames which have trailing "_". [What possesses people to do this is beyond me, but that's beside the point.]

Does anyone know of dire consequences if I replaces the lines above with something like:

$t = trim ($this->mDbkeyform); $t = strtr(t$,' ','_');

This would trim leading and trailing spaces, and convert embedded spaces to underscores, but leave leading and trailing underscores untouched.

Thanks for any thoughts...

-- Joshua