added error checking to install.js for categories

src/categories.js

@@ -275,7 +275,7 @@ var db = require('./database'),
 				return callback(err);
 			}
 
-			if (!Array.isArray(categories)) {
+			if (!Array.isArray(categories) || !categories.length) {
 				return callback(null, []);
 			}
 

src/install.js

@@ -366,27 +366,26 @@ function createCategories(next) {
 	var Categories = require('./categories');
 
 	Categories.getAllCategories(function (err, categoryData) {
-		if (categoryData.length === 0) {
+		if (err) {
+			return next(err);
+		}
+
+		if (Array.isArray(categoryData) && categoryData.length) {
+			winston.info('Categories OK. Found ' + categoryData.length + ' categories.');
+			return next();
+		}
+
 		winston.warn('No categories found, populating instance with default categories');
 
 		fs.readFile(path.join(__dirname, '../', 'install/data/categories.json'), function (err, default_categories) {
+			if (err) {
+				return next(err);
+			}
 			default_categories = JSON.parse(default_categories);
 
-				async.eachSeries(default_categories, function (category, next) {
-					Categories.create(category, next);
-				}, function (err) {
-					if (!err) {
-						next();
-					} else {
-						winston.error('Could not set up categories');
-					}
+			async.eachSeries(default_categories, Categories.create, next);
 		});
 	});
-		} else {
-			winston.info('Categories OK. Found ' + categoryData.length + ' categories.');
-			next();
-		}
-	});
 }
 
 function enableDefaultPlugins(next) {