WP_User class uses ID as username when $id = null

[kawauso]

WP_User's __construct() function has:

if ( ! is_numeric( $id ) ) {
	$name = $id;
	$id = 0;
}

presumably for when people incorrectly pass the username as the ID. However, this also returns true when the ID is set as null and is used as the username.

Code to reproduce:

add_action( 'admin_init', 'display_admin_user' );

function display_admin_user() {
	$user_by_name = new WP_User( null, 'admin' );
	$user_by_id = new WP_User( 1 );

	echo '<p>' . print_r( $user_by_name, true ) . '</p>';
	echo '<p>' . print_r( $user_by_id, true ) . '</p>';
}

[kawauso]

! empty( $id )

[kawauso]

Refresg

[ryan]

In [18598]:

Handle null user ID in the WP_User constructor. Props kawauso. fixes #17894

[ryan]

Unit test added: ​http://unit-tests.trac.wordpress.org/changeset/429