Merge pull request #1426 from donaldguy/patch-1

Don't ignore Db-level authSource on log-in

Author: christkv

lib/db.js

@@ -1450,9 +1450,10 @@ var authenticate = function(self, username, password, options, callback) {
 
   // the default db to authenticate against is 'self'
   // if authententicate is called from a retry context, it may be another one, like admin
-  var authdb = options.authdb ? options.authdb : options.dbName;
+  var authdb = options.dbName ? options.dbName : self.databaseName;
+  authdb = self.authSource ? self.authSource : authdb;
+  authdb = options.authdb ? options.authdb : authdb;
   authdb = options.authSource ? options.authSource : authdb;
-  authdb = authdb ? authdb : self.databaseName;
 
   // Callback
   var _callback = function(err, result) {