Winbind authentication fails when a few signals are waiting in select_pipe (Samba 3.0.20)

[Dina Fine]

Hi

Winbind (Samba 3.0.20) returns errors on any client request if a few
signals were sent to winbindd processes.

For example if I will send USR1 signal 7 times, the select_pipe will
have 7 signals written
It means that user will success to authenticate only on 8 retry.

This is because the cm_open_connection() doesn't check the sys_select
error, and fails even on EINTR. (instead of trying again).

[2006/06/07 08:15:33, 3, pid=725]
lib/util_sock.c:open_any_socket_out(1015)
  Select failed with error(4) - Interrupted system call
[2006/06/07 08:15:33, 3, pid=725]
lib/util_sock.c:open_any_socket_out(1063)
  In done, resulting index is -1
[2006/06/07 08:15:33, 3, pid=725]
nsswitch/winbindd_cm.c:find_new_dc(703)
  Adding connection() to failed connections
[2006/06/07 08:15:33, 3, pid=725]
nsswitch/winbindd_misc.c:winbindd_dual_check_machine_acct(71)
  could not open handle to NETLOGON pipe
[2006/06/07 08:15:33, 2, pid=725]
nsswitch/winbindd_misc.c:winbindd_dual_check_machine_acct(101)
  Checking the trust account password returned
NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND

Thanks
Dina