* dtable.cc (dtable::delete_archetype): Improve debugging output.

(dtable::init_std_file_from_handle): Close console handle early, before
initialization.  Build up openflags for passing to open_setup, just to be safe.
(last_tty_dev): New variable.
(fh_last_tty_dev): New macro.
(fh_alloc): Try again to keep track of previously opened tty, this time by just
saving the device and using that to potentially open an archetype.  Avoid
setting the "/dev/tty" name if the creation of the fhandler failed.
(build_fh_pc): Remove unused second argument.  Reorganize how and where the
name is set.  Set last_tty_dev as appropriate.  Avoid a NULL dereference in a
debug printf.
* dtable.h (build_fh_pc): Reflect removal of second parameter.
* fhandler.cc (fhandler_base::reset): Use new '<<' operator to copy pc since it
preserves any potentially previously set name.
(fhandler_base::set_name): Ditto.
* fhandler.h (fhandler_*::clone): Throughout use ccalloc to allocate new
fhandler, primarily to make sure that pc field is properly zeroed.
(fhandler_termios::last): Eliminate.
(fhandler_termios): Remove setting of last.
(fhandler_base::~fhandler_termios): Ditto.
* fhandler_console.cc (fhandler_console::open): Don't make decisions about
opening close-on-exec handles here since it makes no sense for archetypes.
(fhandler_console::init): Assume that input handle has already been opened.
* fhandler_termios.cc (fhandler_termios::last): Delete.
* path.h (path_conv::eq_worker): New function.  Move bulk of operator = here.
(operator <<): New function.
(operator =): Use eq_worker to perform old functionality.

winsup/cygwin/pinfo.cc

@@ -375,6 +375,9 @@ _pinfo::_ctty (char *buf)
 bool
 _pinfo::set_ctty (fhandler_termios *fh, int flags)
 {
+debug_printf ("fh %p", fh);
+debug_printf ("tc %p", fh->tc ());
+if (!this || !fh->tc ()) try_to_debug ();
   tty_min& tc = *fh->tc ();
   debug_printf ("old %s, ctty device number %p, tc.ntty device number %p flags & O_NOCTTY %p", __ctty (), ctty, tc.ntty, flags & O_NOCTTY);
   if (fh && &tc && (ctty <= 0 || ctty == tc.ntty) && !(flags & O_NOCTTY))