add_query_arg() uses REQUEST_URI when it is undesirable to do so
|Reported by:||markjaquith||Owned by:||anonymous|
mod_rewrite permalinks, blog URL as domain root.
echo remove_query_arg('arbitrary', '');
expected result is a blank string (remove a query arg from a blank string, you should get that same blank string back).
It's using the REQUEST URI because it thinks you haven't provided your own query string. But you have... it's just blank. add_query_arg() and remove_query_arg() need to use something other than a blank string to designate that the user has neglected to provide their own QS.