This patch is taken from suggestions by Bruno Haible in:
http://lists.gnu.org/archive/html/bug-gnulib/2017-02/msg00060.html
http://lists.gnu.org/archive/html/bug-gnulib/2017-02/msg00061.html
* lib/binary-io.c (__gl_setmode_check): Set errno to EINVAL,
not ENOTTY, when it is an inappropriate device.
* lib/binary-io.h (SET_BINARY): Resurrect.
* lib/xbinary-io.c: Rename from lib/xsetmode.c.
(xset_binary_mode_error): Rename from xsetmode_error.
* lib/xbinary-io.h: Rename from lib/xsetmode.h.
(xset_binary_mode): Rename from xsetmode.
All uses changed.
* modules/xbinary-io: Rename from modules/xsetmode.
Update file names.
* tests/test-binary-io.sh (tmpfiles): Remove no-longer-used file name.
* NEWS: Update to match revised behavior.