Hi There,

I understand this post may not be 100% correct in this forum however I'm going to ask the question anyway as it does involve using Umbraco and a possible bug.

We are developing an Umbraco site for a client. They also have a Sharepoint site that some members will need to log on to. Instead of providing those users with seperate logons for both systems we want SharePoint to use the Umbraco membership provider. I was under the impression that the umbraco provider had to conform to the standard .net membership provider as umbraco can also be used with other membership providers such as the standard .net one (aspnetdb).

I've been though all the SharePoint configuration (web config and authentication provider config within central site admin in SharePoint). Looking at the logs it appears it is trying to use the umbraco membership provider but is getting a "Object reference not set to an instance of an object" exception.

This is the reason I'm posting the topic in this forum as I believe it is a possible problem in the umbraco.providers or umbraco.cms.businesslogic.member code. I may be completely wrong also but have tried to diagnose this and am currently downloading the source to try and fix it myself however I just thought I'd ask if anyone had any ideas!

The SharePoint error log shows this:

Error in searching user 'neil marshall' : System.NullReferenceException: Object reference not set to an instance of an object.     at umbraco.cms.businesslogic.member.Member.IsMember(String loginName)     at umbraco.cms.businesslogic.member.Member.GetMemberFromLoginName(String loginName)     at umbraco.providers.members.Helper.GetMemberByUsernameOrGuid(String userNameOrGuid)     at umbraco.providers.members.UmbracoMembershipProvider.GetUser(String username, Boolean userIsOnline)     at Microsoft.SharePoint.Utilities.SPMembershipProviderPrincipalResolver.ResolvePrincipal(String input, Boolean inputIsEmailOnly, SPPrincipalType scopes, SPPrincipalSource sources, SPUserCollection usersContainer)     at Microsoft.SharePoint.Utilities.SPMembershipProviderPrincipalResolver.SearchPrincipals(String... 
02/03/2010 13:32:10.72* w3wp.exe (0x0848)                        0x1F74 Windows SharePoint Services    General                        72e7 Medium   ... input, SPPrincipalType scopes, SPPrincipalSource sources, SPUserCollection usersContainer, Int32 maxCount, Boolean& bReachMaxCount)     at Microsoft.SharePoint.Utilities.SPUtility.SearchPrincipalFromResolvers(List`1 resolvers, String input, SPPrincipalType scopes, SPPrincipalSource sources, SPUserCollection usersContainer, Int32 maxCount, Boolean& reachMaxCount, Dictionary`2 usersDict). 

I've been through each of the method mentioned in the error entry in reverse order (as the first one mentioned is presumably where the problem lies and wanted to see the path to it) and pulled out each of them to see if I can see any problem in any of them:

        public override MembershipUser GetUser(string username, bool userIsOnline)
        {
            Member m = Helper.GetMemberByUsernameOrGuid(username);

            if (m == null)
            {
                return null;
            }
            else
            {
                return ConvertToMembershipUser(m);
            }
        }

public static Member GetMemberByUsernameOrGuid(string userNameOrGuid)
        {
            Member m = null;

            // test if username is a GUID (then it comes from member core login)
            if (GuidPseudoTryParse(userNameOrGuid))
            {
                m = new Member(new Guid(userNameOrGuid));
            }
            else
            {
                m = Member.GetMemberFromLoginName(userNameOrGuid);
            }

            return m;
        }

public static Member GetMemberFromLoginName(string loginName)
        {
            if (IsMember(loginName))
            {
                object o = SqlHelper.ExecuteScalar<object>(
                    "select nodeID from cmsMember where LoginName = @loginName",
                    SqlHelper.CreateParameter("@loginName", loginName));

                if (o == null)
                    return null;

                int tmpId;
                if (!int.TryParse(o.ToString(), out tmpId))
                    return null;

                return new Member(tmpId);
            }
            else
                HttpContext.Current.Trace.Warn("No member with loginname: " + loginName + " Exists");

            return null;
        }

        public static bool IsMember(string loginName)
        {
            Debug.Assert(loginName != null, "loginName cannot be null");
            object o = SqlHelper.ExecuteScalar<object>(
                "select count(nodeID) as tmp from cmsMember where LoginName = @loginName",
                SqlHelper.CreateParameter("@loginName", loginName));
            if (o == null)
                return false;
            int count;
            if (!int.TryParse(o.ToString(), out count))
                return false;
            return count > 0;
        }

Thanks for any help you can provide!