[Bug c++/68213] New: Exception handling corrupts a VLA in MinGW

["hedayat.fwd at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68213

            Bug ID: 68213
           Summary: Exception handling corrupts a VLA in MinGW
           Product: gcc
           Version: 5.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hedayat.fwd at gmail dot com
  Target Milestone: ---

Code:
-----------------------------------------------------------------
#include <iostream>
#include <cstring>
#include <sstream>
#include <stdexcept>

using namespace std;

int main(int argc, char **argv)
{
        int n;
        stringstream ss(argv[1]);
        ss >> n;
        cout << "N: " << n << endl;
        char tbuff[n];
        try
        {
                memset(tbuff, 0, n);
                throw runtime_error("ERR");
        }
        catch (exception &e)
        {
                cout << "Writing to VLA" << endl;
                memset(tbuff, 0, n);
                cout << "Wrote" << endl;
        }
}
-----------------------------------------------------------------

Compiled with: 
/usr/bin/i686-w64-mingw32-g++ -O2  test.cpp -o t

Run with wine (similar results under Windows) results in crash:
[]% ./t 100                                         
fixme:winediag:start_process Wine Staging is a testing version containing
experimental patches.
fixme:winediag:start_process Please report bugs at http://bugs.wine-staging.com
(instead of winehq.org).
N: 100
Writing to VLA
wine: Unhandled page fault on read access to 0x00000000 at address (nil)
(thread 0009), starting debugger...
Unhandled exception: page fault on read access to 0x00000000 in 32-bit code
(0x00000000).
....