People Picker showing same user twice in SharePoint 2010

Question

First of all I am new to SP 2010 FBA.

Please see the below scenario;

I created a web app which supports both FBA and Windows authentication. Then I created some users using the MemberShip Seeder tool in this web app. Now on I search the user using people picker the same user is appearing twice. One in upper case and the other in lower case. Whichever user I am clicking/selecting the exact user is only getting added. The issue is appearing only if I am searching with lower case. If I am entering names with uppercase letters, then everything is working fine.

So please anyone, provide your suggestions to resolve the issue.

Thanks in advance

Answer 1

I have faced similar issue while using Claims authentication.

On close inspection I found that the returned duplicate results were having different login names. For example if one result was ads\john then the other one was i:0#.w|ads\john.

It is easy to remove such duplicates if you are programming against server side directly with the following API code:

private string GetLoginName(string name)
{
     var manager = SPClaimProviderManager.Local;
     if (manager != null)
     {
         return SPClaimProviderManager.IsEncodedClaim(name) ? manager.DecodeClaim(name).Value : name;
     }
     return name;
}

I have blogged about it here:

http://www.madhur.co.in/blog/2014/01/29/convert-claim-based-login-name.html