Prevent LDAP authentication with empty password related problems.

git-svn-id: http://redmine.rubyforge.org/svn/trunk@1231 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/user.rb

@@ -83,6 +83,8 @@ class User < ActiveRecord::Base
   
   # Returns the user that matches provided login and password, or nil
   def self.try_to_login(login, password)
+    # Make sure no one can sign in with an empty password
+    return nil if password.to_s.empty?
     user = find(:first, :conditions => ["login=?", login])
     if user
       # user is already in local database