[Bug libstdc++/83754] New: Segmentation fault in regex_search

["antoshkka at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83754

            Bug ID: 83754
           Summary: Segmentation fault in regex_search
           Product: gcc
           Version: 7.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: antoshkka at gmail dot com
  Target Milestone: ---

The following code 

#include <regex>
#include <string>

int main() {
  std::regex pattern("\\w+\\.");
  std::string s(1000000, 'a');
  return std::regex_search(s, pattern);
}


leads to segmentation fault. Backtrace reports the following:

#1  0x00000000004174a2 in std::_Function_handler<bool (char),
std::__detail::_BracketMatcher<std::regex_traits<char>, false, false>
>::_M_invoke(std::_Any_data const&, char&&) ()
#2  0x0000000000415544 in std::function<bool (char)>::operator()(char) const ()
#3  0x0000000000411222 in std::__detail::_State<char>::_M_matches(char) const
()
#4  0x000000000040cde3 in std::__detail::_Executor<skip>::_M_handle_match
<Following block is repeated thousands of times:>
#5  0x0000000000409cb0 in std::__detail::_Executor<skip>::_M_dfs
#6  0x0000000000411656 in std::__detail::_Executor<skip>::_M_rep_once_more
#7  0x000000000040ca05 in std::__detail::_Executor<skip>::_M_handle_repeat
<...>
#11350  0x0000000000409cb0 in std::__detail::_Executor<skip>::_M_dfs
#11351  0x0000000000411656 in std::__detail::_Executor<skip>::_M_rep_once_more
#11352  0x000000000040ca05 in std::__detail::_Executor<skip>::_M_handle_repeat
<...>


This issue could be related to the bug 79539