[Bug c++/64429] New: Double free when returning std::string from trivial lambda

[Bug c++/64429] New: Double free when returning std::string from trivial lambda

[charlie at charliedyson dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64429

            Bug ID: 64429
           Summary: Double free when returning std::string from trivial
                    lambda
           Product: gcc
           Version: 4.8.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: charlie at charliedyson dot net

The following causes a double free on gcc 4.8.2 as shipped with Ubuntu, and
various other versions I tested on Wandbox.

Interestingly enough, explicitly copying the string inside the lambda seems to
fix it.

Code:

#include <string>

using F = std::string(*)(std::string);

std::string call_fn_pointer(F f, std::string s)
{
    return f(s);
}

std::string f(std::string s) { return s; }

int main()
{
    // fine
    call_fn_pointer(f, "foo");

    // fine
    call_fn_pointer([] (std::string s) { return std::string(s); }, "foo");

    // double free
    call_fn_pointer([] (std::string s) { return s; }, "foo");
}

Invocation:
$ g++ -std=c++1y foo.cpp -o foo -Wall
$ ./foo 
*** Error in `./foo': double free or corruption (fasttop): 0x08372008 ***
Aborted

Apologies in advance if I've found another duplicate! Could this relate to
64329?

[Bug c++/64429] Double free when returning std::string from trivial lambda

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64429

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
More likely to be PR 62052