-- NOTE: FOR INTERNAL SECURITY USE ONLY!
--      DO NOT DOCUMENT OR USE!

create procedure sys.sp_MSadduser_implicit_ntlogin
    @ntname         sysname
AS
	declare @ret		int
	
    -- NO-OP IF LOGIN ALREADY EXISTS 
	if database_principal_id(@ntname) is null
	begin

        -- MUST BE NT NAME 
        if (charindex('\', @ntname) = 0)
            return (1)

	    declare	@newsid	varbinary(85),
				@isgrp	bit

        -- OBTAIN NT SID FOR THIS USER (SET STATUS BITS) 
	    select @newsid = get_sid('\U'+@ntname)	    -- NT user
	    if (@newsid is Null)
	    begin
	        select @isgrp = 1, @newsid = get_sid('\G'+@ntname)    -- NT group
	        IF (@newsid IS Null)
		        return (1)
	    end
        else
            select @isgrp = 0	-- NTUser

        -- FAIL IF SID ALREADY IN SYSUSERS 
        if exists (select sid from sysusers where sid = @newsid)
            return (1)

		BEGIN TRANSACTION

        -- ADD IMPLICIT SYSUSERS ENTRY & INVALIDATE UID CACHE FOR THIS DB 
		EXEC %%Owner().NewUserOrGroup(Name = @ntname, SID = @newsid,
			IsExternal = 1, IsGroup = @isgrp)

		-- RETURN FAILURE/SUCCESS 
		select @ret = @@error
		if @ret <> 0
		begin
			COMMIT TRANSACTION
			return @ret
		end

		COMMIT TRANSACTION
    end

    -- SUCCESS 
    return (0) -- sp_MSadduser_implicit_ntlogin