diff -cr cygwin-1.5.5-1.orig/winsup/cygwin/fhandler_serial.cc cygwin-1.5.5-1/winsup/cygwin/fhandler_serial.cc
*** cygwin-1.5.5-1.orig/winsup/cygwin/fhandler_serial.cc	Sat Jun 21 02:12:35 2003
--- cygwin-1.5.5-1/winsup/cygwin/fhandler_serial.cc	Tue Jan 20 10:57:31 2004
***************
*** 153,174 ****
  int
  fhandler_serial::raw_write (const void *ptr, size_t len)
  {
!   DWORD bytes_written;
    OVERLAPPED write_status;
  
    memset (&write_status, 0, sizeof (write_status));
    write_status.hEvent = CreateEvent (&sec_none_nih, TRUE, FALSE, NULL);
    ProtectHandle (write_status.hEvent);
  
!   for (;;)
      {
        if (WriteFile (get_handle (), ptr, len, &bytes_written, &write_status))
  	break;
  
        switch (GetLastError ())
  	{
! 	case ERROR_OPERATION_ABORTED:
! 	  continue;
  	case ERROR_IO_PENDING:
  	  break;
  	default:
--- 153,179 ----
  int
  fhandler_serial::raw_write (const void *ptr, size_t len)
  {
!   DWORD bytes_written = 0;
    OVERLAPPED write_status;
  
    memset (&write_status, 0, sizeof (write_status));
    write_status.hEvent = CreateEvent (&sec_none_nih, TRUE, FALSE, NULL);
    ProtectHandle (write_status.hEvent);
  
!   for (int prevent_deadlock=0 ; prevent_deadlock<10 ; prevent_deadlock++)
      {
        if (WriteFile (get_handle (), ptr, len, &bytes_written, &write_status))
  	break;
  
        switch (GetLastError ())
  	{
! 	case ERROR_OPERATION_ABORTED: {
! 	  DWORD ev;
! 	  COMSTAT st;
! 	  if (!ClearCommError (get_handle (), &ev, &st))
! 	     __seterrno ();
! 	  bytes_written = 0;
! 	  continue; }
  	case ERROR_IO_PENDING:
  	  break;
  	default: