closes #2196

src/notifications.js

@@ -136,7 +136,9 @@ var async = require('async'),
 		var unreadKeys = [];
 		var readKeys = [];
 
-		uids.filter(Boolean).forEach(function(uid) {
+		uids.filter(function(uid) {
+			return parseInt(uid, 10);
+		}).forEach(function(uid) {
 			unreadKeys.push('uid:' + uid + ':notifications:unread');
 			readKeys.push('uid:' + uid + ':notifications:read');
 		});

src/user/notifications.js

@@ -211,6 +211,9 @@ var async = require('async'),
 	};
 
 	UserNotifications.getUnreadCount = function(uid, callback) {
+		if (!parseInt(uid, 10)) {
+			return callback(null, 0);
+		}
 		db.sortedSetCard('uid:' + uid + ':notifications:unread', callback);
 	};