create procedure sys.sp_change_log_shipping_secondary_primary
(
    @primary_server sysname -- cannot be NULL
    ,@primary_database sysname -- cannot be NULL
    ,@backup_source_directory nvarchar(500) = NULL
    ,@backup_destination_directory nvarchar(500) = NULL
    ,@file_retention_period int = NULL
    ,@monitor_server_security_mode bit = NULL
    ,@monitor_server_login sysname = NULL
    ,@monitor_server_password sysname = NULL
)
as
begin
    set nocount on
    declare @retcode int
                ,@secondary_id uniqueidentifier
                ,@monitor_server sysname
                ,@existing_security_mode int

    
    -- security check
    
    exec @retcode = sys.sp_MSlogshippingsysadmincheck
    if (@retcode != 0 or @@error != 0)
        return 1
    
    -- must be invoked from master db
    
    if (db_name() != N'master')
    begin
        raiserror(5001, 16,-1)
        return 1
    end
    
    -- Does the primary exist
    
    select @secondary_id = secondary_id
            ,@monitor_server = monitor_server
            ,@existing_security_mode = monitor_server_security_mode
    from msdb.dbo.log_shipping_secondary
    where primary_server = upper(@primary_server)
        and primary_database = @primary_database
    if (@secondary_id is null)
    begin
        raiserror(32023, 16, 1, @primary_server, @primary_database)
        return 1
    end
    
    -- refresh monitor link if the monitor credentials are have been specified
    
    if (upper(@monitor_server) != upper(@@servername)
        and (@monitor_server_security_mode is not null
                or @monitor_server_login is not null
                or @monitor_server_password is not null))
    begin
        
        -- check if only login credentials have changed
        
        if (@monitor_server_security_mode is not null)
            select @existing_security_mode = @monitor_server_security_mode
        
        -- create link for monitor server
        
        exec @retcode = msdb.sys.sp_MSprocesslogshipmonitorlink @mode = 1
                                        ,@monitor_server = @monitor_server
                                        ,@monitor_server_security_mode = @existing_security_mode
                                        ,@monitor_server_login = @monitor_server_login
                                        ,@monitor_server_password = @monitor_server_password
        if (@retcode != 0 or @@error != 0)
            return 1
    end
    
    -- start transaction
    
    begin tran sp_change_ls_sd
    save tran sp_change_ls_sd
    
    -- update log_shipping_secondary
    
    update msdb.dbo.log_shipping_secondary
    set backup_source_directory = case when (@backup_source_directory is null) then backup_source_directory else @backup_source_directory end
         ,backup_destination_directory = case when (@backup_destination_directory is null) then backup_destination_directory else @backup_destination_directory end
         ,monitor_server_security_mode = case when (@monitor_server_security_mode is null) then monitor_server_security_mode else @monitor_server_security_mode end
         ,file_retention_period = case when (@file_retention_period is null) then file_retention_period else @file_retention_period end
    where secondary_id = @secondary_id
    if (@@error != 0)
        goto UNDO
    
    -- commit
    
    commit tran
    
    -- all done
    
    return 0

UNDO:
    rollback tran sp_change_ls_sd
    commit tran
    return 1
end