* 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/fork.cc

@@ -598,6 +598,8 @@ fork ()
   void *esp;
   __asm ("movl %%esp,%0": "=r" (esp));
 
+  myself->set_has_pgid_children ();
+
   child_info_fork ch;
 
   int res = setjmp (ch.jmp);