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, 1 insertions, 1 deletions

diff --git a/admin/merge-gnulib b/admin/merge-gnulib
index 84dcb0b8752..ab0d34e1624 100755
--- a/admin/merge-gnulib
+++ b/admin/merge-gnulib
@@ -32,7 +32,7 @@ GNULIB_MODULES='
   crypto/md5-buffer crypto/sha1-buffer crypto/sha256-buffer crypto/sha512-buffer
   d-type diffseq dosname dtoastr dtotimespec dup2
   environ execinfo explicit_bzero faccessat
-  fcntl fcntl-h fdatasync fdopendir
+  fcntl fcntl-h fdopendir
   filemode filevercmp flexmember fpieee fstatat fsusage fsync
   getloadavg getopt-gnu gettime gettimeofday gitlog-to-changelog
   ieee754-h ignore-value intprops largefile lstat