* debug.cc (add_handle): Issue warning on attempts to add the same handle more

than once.
* fhandler_tty.cc (fhandler_tty_slave::open): Protect some handles.
(fhandler_tty_common::close): Use proper name when closing handles.
(fhandler_pty_master::close): Don't close to_slave or from_slave since they've
already been closed earlier in the function.
* sigproc.cc (proc_subproc): Don't protect vchild->hProcess.  Expect that the
caller will do this, instead.
* tty.cc (tty_list::terminate): Use proper name when closing handles.
(tty::make_pipes): Protect some handles.

winsup/cygwin/sigproc.cc

@@ -258,7 +258,6 @@ proc_subproc (DWORD what, DWORD val)
 
       pchildren[nchildren] = vchild;
       hchildren[nchildren] = vchild->hProcess;
-      ProtectHandle1 (vchild->hProcess, childhProc);
       if (!DuplicateHandle (hMainProc, vchild->hProcess, hMainProc, &vchild->pid_handle,
 			    0, 0, DUPLICATE_SAME_ACCESS))
 	system_printf ("Couldn't duplicate child handle for pid %d, %E", vchild->pid);