1 files changed, 82 insertions, 5 deletions

diff --git a/plugins/jetpack/sync/class.jetpack-sync-module-meta.php b/plugins/jetpack/sync/class.jetpack-sync-module-meta.php
index 5fff16a3..b0e70355 100644
--- a/plugins/jetpack/sync/class.jetpack-sync-module-meta.php
+++ b/plugins/jetpack/sync/class.jetpack-sync-module-meta.php
@@ -7,6 +7,68 @@ class Jetpack_Sync_Module_Meta extends Jetpack_Sync_Module {
 		return 'meta';
 	}
 
+	/**
+	 * This implementation of get_objects_by_id() is a bit hacky since we're not passing in an array of meta IDs,
+	 * but instead an array of post or comment IDs for which to retrieve meta for. On top of that,
+	 * we also pass in an associative array where we expect there to be 'meta_key' and 'ids' keys present.
+	 *
+	 * This seemed to be required since if we have missing meta on WP.com and need to fetch it, we don't know what
+	 * the meta key is, but we do know that we have missing meta for a given post or comment.
+	 *
+	 * @param string $object_type The type of object for which we retrieve meta. Either 'post' or 'comment'
+	 * @param array $config Must include 'meta_key' and 'ids' keys
+	 *
+	 * @return array
+	 */
+	public function get_objects_by_id( $object_type, $config ) {
+		global $wpdb;
+		if ( ! in_array( $object_type, $this->meta_types ) ) {
+			return array();
+		}
+
+		if ( ! isset( $config['meta_key'] ) || ! isset( $config['ids'] ) || ! is_array( $config['ids'] ) ) {
+			return array();
+		}
+
+		$meta_key = $config['meta_key'];
+		$ids = $config['ids'];
+
+		if ( ! $this->is_meta_key_allowed( $meta_key ) ) {
+			return array();
+		}
+
+		if ( 'post' == $object_type ) {
+			$table = $wpdb->postmeta;
+			$object_id_column = 'post_id';
+		} else {
+			$table = $wpdb->commentmeta;
+			$object_id_column = 'comment_id';
+		}
+
+		// Sanitize so that the array only has integer values
+		$ids_string = implode( ', ', array_map( 'intval', $ids ) );
+		$metas = $wpdb->get_results(
+			$wpdb->prepare(
+				"SELECT * FROM {$table} WHERE {$object_id_column} IN ( {$ids_string} ) AND meta_key = %s",
+				$meta_key
+			)
+		);
+
+		$meta_objects = array();
+		foreach( (array) $metas as $meta_object ) {
+			$meta_object = (array) $meta_object;
+			$meta_objects[ $meta_object[ $object_id_column ] ] = array(
+				'meta_type' => $object_type,
+				'meta_id' => $meta_object['meta_id'],
+				'meta_key' => $meta_key,
+				'meta_value' => $meta_object['meta_value'],
+				'object_id' => $meta_object[ $object_id_column ],
+			);
+		}
+
+		return $meta_objects;
+	}
+
 	public function init_listeners( $callable ) {
 		$whitelist_handler = array( $this, 'filter_meta' );
 
@@ -21,15 +83,30 @@ class Jetpack_Sync_Module_Meta extends Jetpack_Sync_Module {
 		}
 	}
 
-	function filter_meta( $args ) {
-		if ( '_' === $args[2][0] &&
-		     ! in_array( $args[2], Jetpack_Sync_Defaults::$default_whitelist_meta_keys ) &&
-		     ! wp_startswith( $args[2], '_wpas_skip_' )
+	/**
+	 * Should we allow the meta key to be synced?
+	 *
+	 * @param string $meta_key The meta key.
+	 *
+	 * @return bool
+	 */
+	function is_meta_key_allowed( $meta_key ) {
+		if ( '_' === $meta_key[0] &&
+		     ! in_array( $meta_key, Jetpack_Sync_Defaults::$default_whitelist_meta_keys ) &&
+		     ! wp_startswith( $meta_key, '_wpas_skip_' )
 		) {
 			return false;
 		}
 
-		if ( in_array( $args[2], Jetpack_Sync_Settings::get_setting( 'meta_blacklist' ) ) ) {
+		if ( in_array( $meta_key, Jetpack_Sync_Settings::get_setting( 'meta_blacklist' ) ) ) {
+			return false;
+		}
+
+		return true;
+	}
+
+	function filter_meta( $args ) {
+		if ( ! $this->is_meta_key_allowed( $args[2] ) ) {
 			return false;
 		}