https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98001
--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:2762cb1df686fc1ebcee23c7c4f0f6e8bf5a6abc commit r11-5437-g2762cb1df686fc1ebcee23c7c4f0f6e8bf5a6abc Author: Jonathan Wakely <jwak...@redhat.com> Date: Thu Nov 26 11:25:55 2020 +0000 libstdc++: Fix undefined FILE* operations in test We only need to check that the constructor doesn't clear errno, so there's no need to use an invalid FILE* for that. libstdc++-v3/ChangeLog: PR libstdc++/98001 * testsuite/ext/stdio_filebuf/char/79820.cc: Do not pass invalid FILE* to constructor.