* dtable.cc (dtable::vfork_parent_restore): Add debugging statement.

* exceptions.cc (try_to_debug): Spin only as long as we don't have a debugger
attached.
* fhandler.h (fhandler_base::set_nohandle): New method.
(fhandler_base::get_nohandle): New method.
* fhandler.cc (fhandler_base::dup): Avoid duplicating handle if there is no
handle.
* fhandler_disk_file.cc (fhandler_disk_file::opendir): Set nohandle flag on
dummy fd.
* Makefile.in: Make intermediate library for eventual inclusion in libcygwin.a
* fhandler.h (fhandler_pipe::fhandler_pipe): Remove default argument setting
since it is no longer used.
* miscfuncs.cc (check_null_str): New function.
(+check_null_str_errno): Ditto.
* net.cc: Add defensive buffer checking throughout.
(cygwin_sendto): Protect against invalid fd.
(cygwin_recvfrom): Ditto.
(cygwin_getpeername): Ditto.
(cygwin_recv): Ditto.
(cygwin_send): Ditto.
* winsup.h: Declare a new function.
* select.cc (set_bits): Fix conditional for setting fd in exceptfds.
* dtable.cc (dtable::build_fhandler): Create fhandler_pipe using correct device
type.
* path.cc (get_devn): Set correct pipe device type from device name.

winsup/cygwin/fhandler_disk_file.cc

@@ -599,6 +599,7 @@ fhandler_disk_file::opendir (path_conv& real_name)
       dir->__d_dirent->d_version = __DIRENT_VERSION;
       cygheap_fdnew fd;
       fd = this;
+      fd->set_nohandle (true);
       dir->__d_dirent->d_fd = fd;
       dir->__d_u.__d_data.__fh = this;
       /* FindFirstFile doesn't seem to like duplicate /'s. */