https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84110
--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-11 branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:5df21c00aedb7878b8854901e95d7eda70266d31 commit r11-10118-g5df21c00aedb7878b8854901e95d7eda70266d31 Author: Jonathan Wakely <jwak...@redhat.com> Date: Wed Sep 29 13:48:11 2021 +0100 libstdc++: std::basic_regex should treat '\0' as an ordinary char [PR84110] When the input sequence contains a _CharT(0) character, the strchr call in _Scanner<_CharT>::_M_scan_normal() will search for '\0' and so return a pointer to the terminating null at the end of the string. This makes the scanner think it's found a special character. Because it doesn't match any of the actual special characters, we fall off the end of the function (or assert in debug mode). We should check for a null character explicitly and either treat it as an ordinary character (for the ECMAScript grammar) or an error (for all others). I'm not 100% sure that's right, but it seems consistent with the POSIX RE rules where a '\0' means the end of the regex pattern or the end of the sequence being matched. Signed-off-by: Jonathan Wakely <jwak...@redhat.com> libstdc++-v3/ChangeLog: PR libstdc++/84110 * include/bits/regex_error.h (regex_constants::_S_null): New error code for internal use. * include/bits/regex_scanner.tcc (_Scanner::_M_scan_normal()): Check for null character. * testsuite/28_regex/basic_regex/84110.cc: New test. (cherry picked from commit b701e1f8f6870c0f8cb4050674da489101dd05a5)
