backport WordPress/performance#645

Author: aristath

wp-includes/sqlite/class-wp-sqlite-db.php

@@ -112,7 +112,7 @@ public function esc_like( $text ) {
 	 *
 	 * @param string $str The error to display.
 	 *
-	 * @return bool False if the showing of errors is disabled.
+	 * @return bool|void False if the showing of errors is disabled.
 	 */
 	public function print_error( $str = '' ) {
 		global $EZSQL_ERROR;
@@ -194,6 +194,7 @@ public function flush() {
 	 * @see wpdb::db_connect()
 	 *
 	 * @param bool $allow_bail Not used.
+	 * @return void
 	 */
 	public function db_connect( $allow_bail = true ) {
 		$this->init_charset();

wp-includes/sqlite/class-wp-sqlite-pdo-engine.php

@@ -717,7 +717,7 @@ private function prepare_query() {
 	 *
 	 * @param object $statement The PDO statement.
 	 *
-	 * @return boolean
+	 * @return boolean|void
 	 */
 	private function execute_query( $statement ) {
 		$reason  = 0;
@@ -1270,7 +1270,7 @@ private function process_results( $engine ) {
 	 * @param string $function Indicate the function name where the error occurred.
 	 * @param string $message  The message.
 	 *
-	 * @return boolean
+	 * @return boolean|void
 	 */
 	private function set_error( $line, $function, $message ) {
 		global $wpdb;
@@ -1503,6 +1503,8 @@ public function beginTransaction() {
 	 * Method to call PDO::commit().
 	 *
 	 * @see PDO::commit()
+	 *
+	 * @return void
 	 */
 	public function commit() {
 		$this->pdo->commit();
@@ -1513,6 +1515,8 @@ public function commit() {
 	 * Method to call PDO::rollBack().
 	 *
 	 * @see PDO::rollBack()
+	 *
+	 * @return void
 	 */
 	public function rollBack() {
 		$this->pdo->rollBack();

wp-includes/sqlite/class-wp-sqlite-pdo-user-defined-functions.php

@@ -443,6 +443,7 @@ private function derive_interval( $interval ) {
 				list($years, $months) = explode( '-', $_parts[0] );
 				return 'P' . $years . 'Y' . $months . 'M';
 		}
+		return '';
 	}
 
 	/**