Exit the script early if the class doesn't exist, or it's been manually disabled.

Author: earthlingdavey

object-cache.php

@@ -7,6 +7,13 @@
  * can use this to guarantee uniqueness for the keys generated by this object cache.
  */
 
+if ( ! defined( 'WP_REDIS_USE_RELAY' ) ) {
+	define( 'WP_REDIS_USE_RELAY', false );
+}
+
+// Conditionally run the script if: the correct class exists, and the script has not been disabled.
+if ( class_exists( WP_REDIS_USE_RELAY ? 'Relay\Relay' : 'Redis' ) && ( ! defined( 'WP_REDIS_DISABLED' ) || ! WP_REDIS_DISABLED ) ):
+
 if ( ! defined( 'WP_CACHE_KEY_SALT' ) ) {
 	define( 'WP_CACHE_KEY_SALT', '' );
 }
@@ -1293,7 +1300,7 @@ public function build_client_parameters( $redis_server ) {
 	 * @return Redis Redis client.
 	 */
 	public function prepare_client_connection( $client_parameters ) {
-		if ( defined( 'WP_REDIS_USE_RELAY' ) && WP_REDIS_USE_RELAY ) {
+		if ( WP_REDIS_USE_RELAY ) {
 			$redis = new Relay\Relay();
 		} else {
 			$redis = new Redis();