1 files changed, 10 insertions, 8 deletions
diff --git a/lib/plugins/registry.js b/lib/plugins/registry.js
index bc17a8c..ea172c4 100644
--- a/lib/plugins/registry.js
+++ b/lib/plugins/registry.js
@@ -23,7 +23,7 @@ function pluginId(name) {
 
 // Validate an NPM plugin ID
 function validateId(name) {
-    return name.indexOf(PLUGIN_PREFIX) === 0;
+    return name && name.indexOf(PLUGIN_PREFIX) === 0;
 }
 
 // Initialize NPM for operations
@@ -107,24 +107,25 @@ function installPlugin(book, plugin, version) {
 }
 
 // List all packages installed inside a folder
-// Returns a map { pluginName -> folder }
+// Returns an ordered list of plugins
 function listInstalled(folder) {
     var options = {
         dev: false,
         log: function() {},
         depth: 4
     };
-    var result = {};
+    var results = [];
 
     function onPackage(pkg, isRoot) {
         if (!validateId(pkg.name)){
             if (!isRoot) return;
         } else {
-            result[pluginId(pkg.name)] = {
+            results.push({
+                name: pluginId(pkg.name),
                 version: pkg.version,
                 path: pkg.realPath,
                 depth: pkg.depth
-            };
+            });
         }
 
         _.each(pkg.dependencies, function(dep) {
@@ -135,18 +136,19 @@ function listInstalled(folder) {
     return Promise.nfcall(readInstalled, folder, options)
     .then(function(data) {
         onPackage(data, true);
-        return result;
+        return _.uniq(results, 'name');
     });
 }
 
 // List installed plugins for a book (defaults and installed)
 function listPlugins(book) {
-    return Promise.nfcall([
+    return Promise.all([
         listInstalled(path.resolve(__dirname, '../..')),
         listInstalled(book.root)
     ])
     .spread(function(defaultPlugins, plugins) {
-        return _.extend(defaultPlugins, plugins);
+        var results = plugins.concat(defaultPlugins);
+        return _.uniq(results, 'name');
     });
 }