FIONREAD with select

[Nick Roberts <nickrob@snap.net.nz>]

I'm trying to get Gpm (a mouse server for a console) to work with Emacs through
a Unix socket.  To do this I am using select in read_avail_input to catch mouse
events (on gpm_fd) and usual keyboard input (input_fd).  For some reason with
keyboard input, after passing through select,

ioctl (input_fd, FIONREAD, &n_to_read)

always reports no bytes to read (without select it's always 1).

Does anybody know what I'm doing wrong?

-- 
Nick                                           http://www.inet.net.nz/~nickrob


        if (n_to_read == 0)
  	return 0;
  #else /* not MSDOS */
+ #ifdef HAVE_GPM
+       fd_set readset;
+       if (term_gpm)
+ 	{
+ 	  Gpm_Event event;
+ 	  int gpm = 1;
+ 	  struct input_event hold_quit;
+ 	  struct timeval timeout;
+ 
+ 	  /* How long `select' should wait.  */
+ 	  timeout.tv_sec = 0;
+ 	  timeout.tv_usec = 10000;
+ 
+ 	  hold_quit.kind = NO_EVENT;
+ 
+ 	  while (gpm) {
+ 	    FD_ZERO (&readset);
+ 	    FD_SET (gpm_fd, &readset);
+ 	    FD_SET (input_fd, &readset);
+ 
+ 	    if (select (max (input_fd, gpm_fd) + 1, &readset, NULL, NULL, NULL)
+ 		< 0 && errno == EINTR)
+ 	      continue;
+ 	    gpm = FD_ISSET (gpm_fd, &readset);
+ 	    if (gpm) {
+ 	      if (Gpm_GetEvent (&event) > 0) {
+ 		nread += handle_one_term_event (&event, &hold_quit);
+ 	      }
+ 	      else
+ 		hold_quit.kind = NO_EVENT;
+ 	    }
+ 	  }
+ 	  if (hold_quit.kind != NO_EVENT)
+ 	    kbd_buffer_store_event (&hold_quit);
+ 	}
+ #endif /* HAVE_GPM */
  #ifdef FIONREAD
 
      /* Find out how much input is available.  */
        if (ioctl (input_fd, FIONREAD, &n_to_read) < 0)
  	/* Formerly simply reported no input, but that sometimes led to
  	   a failure of Emacs to terminate.