[Bug libstdc++/78236] regex_iterator constructor is incomplete and creates uninitialized values that may be used

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78236

--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Author: redi
Date: Thu May 18 15:30:42 2017
New Revision: 248230

URL: https://gcc.gnu.org/viewcvs?rev=248230&root=gcc&view=rev
Log:
libstdc++/78236 fix past-the-end std::regex_iterator

Backport from mainline
2016-11-09  Tim Shen  <timshen@google.com>

        PR libstdc++/78236
        * libstdc++-v3/include/bits/regex.h (regex_iterator::regex_iterator()):
        Define end() as _M_pregex == nullptr.
        * libstdc++-v3/include/bits/regex.tcc (regex_iterator::operator==(),
        regex_iterator::operator++()): Fix operator==() and operator++() to
        look at null-ness of _M_pregex on both sides.
        * testsuite/28_regex/regression.cc: New testcase.

Modified:
    branches/gcc-5-branch/libstdc++-v3/ChangeLog
    branches/gcc-5-branch/libstdc++-v3/include/bits/regex.h
    branches/gcc-5-branch/libstdc++-v3/include/bits/regex.tcc
    branches/gcc-5-branch/libstdc++-v3/testsuite/28_regex/regression.cc