From bc2fa13d22d991e8f535fa909a42b72c8ee27261 Mon Sep 17 00:00:00 2001
From: Sahat Yalkabov <sakhat@gmail.com>
Date: Fri, 6 Dec 2013 02:03:27 -0500
Subject: [PATCH] Sparse indexing on username field to prevent duplicate null
 username error

---
 models/User.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/models/User.js b/models/User.js
index 8733d9b84d..2d862c3271 100644
--- a/models/User.js
+++ b/models/User.js
@@ -4,7 +4,7 @@ var mongoose = require('mongoose'),
 var userSchema = new mongoose.Schema({
 
   // Local authentication
-  username: { type: String, index: true, unique: true },
+  username: { type: String, unique: true, sparse: true },
   password: String,
 
   // OAuth 2.0 authentication