setpgrp on msdos and w32

[Dan Nicolaescu]

Does setpgrp do anything in our msdos and w32 ports?

The #else branch of this code from callproc.c:child_setup

#if defined(USG)
#ifndef SETPGRP_RELEASES_CTTY
  setpgrp ();                   /* No arguments but equivalent in this case */
#endif
#else
  setpgrp (pid, pid);
#endif /* USG */

might be executed on msdos and w32.

If setpgrp does not do anything, this code can be moved inside the not 
WINDOWSNT and not MSDOS 
#ifdefs, and that would allow all the code from that point to the end of the 
function to move
up, removing one set of #ifdefs.