Ticket #32605: 32605.patch

src/wp-includes/meta.php

@@ -576 +576 @@
                 return false;
         }
 
+        /**
+         * Filter whether to retrieve metadata of a specific type by its meta ID.
+         *
+         * The dynamic portion of the hook, `$meta_type`, refers to the meta
+         * object type (comment, post, or user). Returning a non-null value
+         * will effectively short-circuit the retrieval.
+         *
+         * @since x.y.z
+         *
+         * @param null|object $value Whether to retrieve the meta row object.
+         * @param int mixed $meta_id Meta row ID.
+         */
+        $check = apply_filters( "get_{$meta_type}_meta_by_mid", null, $meta_id );
+        if ( null !== $check ) {
+                if ( empty( $check ) ) {
+                        return false;
+                }
+
+                if ( isset( $check->meta_value ) ) {
+                        $check->meta_value = maybe_unserialize( $check->meta_value );
+                }
+
+                return $check;
+        }
+
         $id_column = ( 'user' == $meta_type ) ? 'umeta_id' : 'meta_id';
 
         $meta = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $table WHERE $id_column = %d", $meta_id ) );
@@ -621 +646 @@
         $column = sanitize_key($meta_type . '_id');
         $id_column = 'user' == $meta_type ? 'umeta_id' : 'meta_id';
 
+        /**
+         * Filter whether to update metadata of a specific type by its meta ID.
+         *
+         * The dynamic portion of the hook, `$meta_type`, refers to the meta
+         * object type (comment, post, or user). Returning a non-null value
+         * will effectively short-circuit the update.
+         *
+         * @since x.y.z
+         *
+         * @param null|bool $check Whether to allow updating metadata for the given type.
+         * @param int $meta_id Meta row ID.
+         * @param mixed $meta_value Meta value. Must be serializable if non-scalar.
+         * @param string|bool $meta_key Meta key to update.
+         */
+        $check = apply_filters( "update_{$meta_type}_meta_by_mid", null, $meta_id, $meta_value, $meta_key );
+        if ( null !== $check ) {
+                return false;
+        }
+
         // Fetch the meta and go on if it's found.
         if ( $meta = get_metadata_by_mid( $meta_type, $meta_id ) ) {
                 $original_key = $meta->meta_key;
@@ -711 +755 @@
         $column = sanitize_key($meta_type . '_id');
         $id_column = 'user' == $meta_type ? 'umeta_id' : 'meta_id';
 
+        /**
+         * Filter whether to delete metadata of a specific type by its meta ID.
+         *
+         * The dynamic portion of the hook, `$meta_type`, refers to the meta
+         * object type (comment, post, or user). Returning a non-null value
+         * will effectively short-circuit the deletion.
+         *
+         * @since x.y.z
+         *
+         * @param null|bool $check Whether to allow deleting metadata for the given type.
+         * @param int $meta_id Meta row ID.
+         */
+        $check = apply_filters( "delete_{$meta_type}_meta_by_mid", null, $meta_id );
+        if ( null !== $check ) {
+                return false;
+        }
+
         // Fetch the meta and go on if it's found.
         if ( $meta = get_metadata_by_mid( $meta_type, $meta_id ) ) {
                 $object_id = $meta->{$column};

tests/phpunit/tests/meta.php

@@ -31 +31 @@
                 $this->assertFalse( delete_metadata_by_mid( 'user', 0 ) );
                 $this->assertFalse( delete_metadata_by_mid( 'non_existing_meta', $this->delete_meta_id ) );
 
+                // Test short-circuiting deletion.
+                add_filter( 'delete_user_meta_by_mid', '__return_true' );
+                $this->assertFalse( delete_metadata_by_mid( 'user', $this->delete_meta_id ) );
+                remove_filter( 'delete_user_meta_by_mid', '__return_true' );
+
                 // Now let's delete the real meta data
                 $this->assertTrue( delete_metadata_by_mid( 'user', $this->delete_meta_id ) );
 
@@ -76 +81 @@
                 $this->assertTrue( update_metadata_by_mid( 'user', $this->meta_id, 'other_meta_value' ) );
                 $second = get_user_meta( $meta->user_id, $meta->meta_key );
                 $this->assertFalse( $first === $second );
+
+                // Test short-circuiting updates.
+                add_filter( 'update_user_meta_by_mid', '__return_true' );
+                $this->assertFalse( update_metadata_by_mid( 'user', $this->meta_id, 'meta_new_value' ) );
+                remove_filter( 'update_user_meta_by_mid', '__return_true' );
         }
 
         /**