* dcrt0.cc (do_exit): Don't bother looking for pgrp children to send SIGHUP if

process has never created any children.
* fork.cc (fork): Set flag indicating that there is another process with our
process group.
* spawn.cc (spawn_guts): Ditto.
* pinfo.h (set_has_pgid_children): New methods for setting when process has
children in its process group.
* syscalls.cc (setpgid): Clear has_gid_children if pgid changes.

winsup/cygwin/spawn.cc

@@ -678,6 +678,7 @@ skip_arg_parsing:
     }
   else
     {
+      myself->set_has_pgid_children ();
       ProtectHandle (pi.hThread);
       pinfo child (cygpid, 1);
       if (!child)