Use tcdrain, not fdatasync, to drain ttys

fdatasync is for storage devices, not ttys.
* admin/merge-gnulib (GNULIB_MODULES): Remove fdatasync.
* lib/fdatasync.c, m4/fdatasync.m4: Remove.
* lib-src/Makefile.in (LIB_FDATASYNC):
* src/Makefile.in (LIB_FDATASYNC):
Remove.  All uses removed.
* lib-src/emacsclient.c [!DOS_NT]:
Include <termios.h>, for tcdrain.
* lib-src/emacsclient.c (flush_stdout):
* src/sysdep.c (reset_sys_modes): On ttys, use tcdrain instead
of fdatasync (except don’t use either function if DOS_NT).
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.

1 files changed, 0 insertions, 27 deletions

diff --git a/lib/fdatasync.c b/lib/fdatasync.c
deleted file mode 100644
index c474e3dd36c..00000000000
--- a/lib/fdatasync.c
+++ /dev/null
@@ -1,27 +0,0 @@
-/* Emulate fdatasync on platforms that lack it.
-
-   Copyright (C) 2011-2018 Free Software Foundation, Inc.
-
-   This library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU General Public
-   License as published by the Free Software Foundation; either
-   version 3 of the License, or (at your option) any later version.
-
-   This library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   General Public License for more details.
-
-   You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
-
-#include <config.h>
-#include <unistd.h>
-
-int
-fdatasync (int fd)
-{
-  /* This does more work than strictly necessary, but is the best we
-     can do portably.  */
-  return fsync (fd);
-}