https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79820
--- Comment #11 from Jonathan Wakely <redi at gcc dot gnu.org> --- Author: redi Date: Mon Sep 4 17:09:05 2017 New Revision: 251680 URL: https://gcc.gnu.org/viewcvs?rev=251680&root=gcc&view=rev Log: PR libstdc++/81751 don't call fflush(NULL) Backport from mainline 2017-08-09 Jonathan Wakely <jwak...@redhat.com> PR libstdc++/79820 PR libstdc++/81751 * config/io/basic_file_stdio.cc (sys_open(FILE*, ios_base::openmode)): Call fflush on the stream instead of calling sync() while _M_cfile is null. Restore original value of errno. * testsuite/ext/stdio_filebuf/char/79820.cc: New. * testsuite/ext/stdio_filebuf/char/81751.cc: New. Added: branches/gcc-5-branch/libstdc++-v3/testsuite/ext/stdio_filebuf/char/79820.cc branches/gcc-5-branch/libstdc++-v3/testsuite/ext/stdio_filebuf/char/81751.cc Modified: branches/gcc-5-branch/libstdc++-v3/ChangeLog branches/gcc-5-branch/libstdc++-v3/config/io/basic_file_stdio.cc
