WP_REST_Meta_Fields::update_meta_value( int $object_id, string $meta_key, string $name, mixed $value ): true|WP_Error

379	protected function update_meta_value( $object_id, $meta_key, $name, $value ) {380		$meta_type = $this->get_meta_type();381 382		// Do the exact same check for a duplicate value as in update_metadata() to avoid update_metadata() returning false.383		$old_value = get_metadata_raw( $meta_type, $object_id, $meta_key );384		$subtype   = get_object_subtype( $meta_type, $object_id );385 386		if ( is_array( $old_value ) && 1 === count( $old_value )387			&& $this->is_meta_value_same_as_stored_value( $meta_key, $subtype, $old_value[0], $value )388		) {389			return true;390		}391 392		if ( ! current_user_can( "edit_{$meta_type}_meta", $object_id, $meta_key ) ) {393			return new WP_Error(394				'rest_cannot_update',395				/* translators: %s: Custom field key. */396				sprintf( __( 'Sorry, you are not allowed to edit the %s custom field.' ), $name ),397				array(398					'key'    => $name,399					'status' => rest_authorization_required_code(),400				)401			);402		}403 404		if ( ! update_metadata( $meta_type, $object_id, wp_slash( $meta_key ), wp_slash( $value ) ) ) {405			return new WP_Error(406				'rest_meta_database_error',407				/* translators: %s: Custom field key. */408				sprintf( __( 'Could not update the meta value of %s in database.' ), $meta_key ),409				array(410					'key'    => $name,411					'status' => WP_Http::INTERNAL_SERVER_ERROR,412				)413			);414		}415 416		return true;417	}