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<?php
/**
 * @author mircobabini
 */
function thread_mark_as_read_for_user( $thread_id, $user_id ) {
	global $wpdb, $bp;

	$sql = $wpdb->prepare( "UPDATE {$bp->messages->table_name_recipients} SET unread_count = 0 WHERE user_id = %d AND thread_id = %d", $user_id, $thread_id );
	$wpdb->query($sql);

	wp_cache_delete( $user_id, 'bp_messages_unread_count' );
}