[Bug libstdc++/83598] std::basic_regex C++14 conformance issue: resulting flags != passed flags

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83598

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Author: redi
Date: Fri Jan  5 22:22:17 2018
New Revision: 256291

URL: https://gcc.gnu.org/viewcvs?rev=256291&root=gcc&view=rev
Log:
PR libstdc++/83598 don't modify flags passed to std::basic_regex constructors

Backport from mainline
2017-12-27  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/83598
        * include/bits/regex.h (basic_regex): Don't modify flags passed to
        constructors.
        * testsuite/28_regex/basic_regex/ctors/83598.cc: New test.

Added:
   
branches/gcc-7-branch/libstdc++-v3/testsuite/28_regex/basic_regex/ctors/83598.cc
Modified:
    branches/gcc-7-branch/libstdc++-v3/ChangeLog
    branches/gcc-7-branch/libstdc++-v3/include/bits/regex.h