From 5688670da67324e7741a48a5445eb80a39005a7f Mon Sep 17 00:00:00 2001
From: "jeremy@jermolene.com" <jeremy@jermolene.com>
Date: Mon, 20 Apr 2020 12:58:27 +0100
Subject: [PATCH] makelibrary command: Guard against invalid directories

---
 core/modules/commands/makelibrary.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/core/modules/commands/makelibrary.js b/core/modules/commands/makelibrary.js
index 1e0035dab..36a1399a2 100644
--- a/core/modules/commands/makelibrary.js
+++ b/core/modules/commands/makelibrary.js
@@ -33,7 +33,7 @@ Command.prototype.execute = function() {
 		tiddlers = {};
 	// Collect up the library plugins
 	var collectPlugins = function(folder) {
-			var pluginFolders = $tw.utils.getSubdirectories(folder);
+			var pluginFolders = $tw.utils.getSubdirectories(folder) || [];
 			for(var p=0; p<pluginFolders.length; p++) {
 				if(!$tw.boot.excludeRegExp.test(pluginFolders[p])) {
 					pluginFields = $tw.loadPluginFolder(path.resolve(folder,"./" + pluginFolders[p]));
@@ -44,7 +44,7 @@ Command.prototype.execute = function() {
 			}
 		},
 		collectPublisherPlugins = function(folder) {
-			var publisherFolders = $tw.utils.getSubdirectories(folder);
+			var publisherFolders = $tw.utils.getSubdirectories(folder) || [];
 			for(var t=0; t<publisherFolders.length; t++) {
 				if(!$tw.boot.excludeRegExp.test(publisherFolders[t])) {
 					collectPlugins(path.resolve(folder,"./" + publisherFolders[t]));