includes/SpoofUser.php
public function getConflicts() {
		$dbr = $this->getDBSlave();

		// Join against the user table to ensure that we skip stray
		// entries left after an account is renamed or otherwise munged.
		$spoofedUsers = $dbr->select(
			[ 'spoofuser', $this->getTableName() ],
			[ 'su_name' ], // Same thing due to the join. Saves extra variableness
			[
				'su_normalized' => $this->normalized,
				'su_name = ' . $this->getUserColumn(),
			],
			__METHOD__,
			[
				'LIMIT' => 5
			] );

		$spoofs = [];
		foreach ( $spoofedUsers as $row ) {
			array_push( $spoofs, $row->su_name );
		}
		return $spoofs;
	}
public function getConflicts() {
		$dbr = $this->getDBSlave();

		// Join against the user table to ensure that we skip stray
		// entries left after an account is renamed or otherwise munged.
		$spoofedUsers = $dbr->select(
			[ 'spoofuser', $this->getTableName() ],
			[ 'su_name' ], // Same thing due to the join. Saves extra variableness
			[
				'su_normalized' => $this->normalized,
				'su_name = ' . $this->getUserColumn(),
			],
			__METHOD__,
			[
				'LIMIT' => 5
			] );

		$spoofs = [];
		foreach ( $spoofedUsers as $row ) {
			array_push( $spoofs, $row->su_name );
		}
		return $spoofs;
	}
Does the username pass Unicode legality and script-mixing checks?

@return array empty if no conflict, or array containing conflicting usernames