Dead code in add_query_arg()

[hakre]

As it just has been checked that $uri contains at least one ?, then exploding $uri on ? with a limit of 2 must return two elements, right?

	if ( strpos( $uri, '?' ) !== false ) {
		$parts = explode( '?', $uri, 2 );
		if ( 1 == count( $parts ) ) {

So the if clause can never be true, the code is dead.

Stripping the dead.

Shouldn't add_query_arg() be using parse_url() ?

I guess not, since parse_url() doesn't work with relative URLs.

Looks right with the edgecases of ?test and test.php?, an empty item will be returned before, and after respectively, resulting in always having a count of 2.

Related: #16958