load_muplugin_textdomain()

load_muplugin_textdomain( string $domain, string $mu_plugin_rel_path = '' ): bool

function load_muplugin_textdomain( $domain, $mu_plugin_rel_path = '' ) {
	/** @var WP_Textdomain_Registry $wp_textdomain_registry */
	/** @var array<string, WP_Translations|NOOP_Translations> $l10n */
	global $wp_textdomain_registry, $l10n;

	if ( ! is_string( $domain ) ) {
		return false;
	}

	$path = WPMU_PLUGIN_DIR . '/' . ltrim( $mu_plugin_rel_path, '/' );

	$wp_textdomain_registry->set_custom_path( $domain, $path );

	// If just-in-time loading was triggered before, reset the entry so it can be tried again.
	if ( isset( $l10n[ $domain ] ) && $l10n[ $domain ] instanceof NOOP_Translations ) {
		unset( $l10n[ $domain ] );
	}

	return true;
}