boost::container::vector leaks memory

[TeXitoi]

boost::container::vector may leak memory with allocation of size 0. For example, on Debian with libboost1.54-dev 1.54.0-2, with this program:

#include <boost/container/vector.hpp>

int main()
{
    using namespace boost::container;
    vector<int> v1;
    vector<int> v2(v1);

    return 0;
}

I have

$ valgrind --leak-check=full ./test
==15591== Memcheck, a memory error detector
==15591== Copyright (C) 2002-2012, and GNU GPL'd, by Julian Seward et al.
==15591== Using Valgrind-3.8.1 and LibVEX; rerun with -h for copyright info
==15591== Command: ./test
==15591== 
==15591== 
==15591== HEAP SUMMARY:
==15591==     in use at exit: 0 bytes in 1 blocks
==15591==   total heap usage: 1 allocs, 0 frees, 0 bytes allocated
==15591== 
==15591== 0 bytes in 1 blocks are definitely lost in loss record 1 of 1
==15591==    at 0x4C298F9: operator new(unsigned long) (vg_replace_malloc.c:298)
==15591==    by 0x4017F6: __gnu_cxx::new_allocator<int>::allocate(unsigned long, void const*) (new_allocator.h:104)
==15591==    by 0x4015FC: boost::container::container_detail::allocator_version_traits<std::allocator<int>, 1u>::allocation_command(std::allocator<int>&, int, unsigned long, unsigned long, unsigned long&, int* const&) (allocator_version_traits.hpp:144)
==15591==    by 0x401542: boost::container::container_detail::vector_alloc_holder<std::allocator<int>, boost::container::container_detail::integral_constant<unsigned int, 1u> >::allocation_command(int, unsigned long, unsigned long, unsigned long&, int* const&) (vector.hpp:395)
==15591==    by 0x401474: boost::container::container_detail::vector_alloc_holder<std::allocator<int>, boost::container::container_detail::integral_constant<unsigned int, 1u> >::vector_alloc_holder<std::allocator<int> >(std::allocator<int> const&, unsigned long) (vector.hpp:350)
==15591==    by 0x401104: boost::container::container_detail::vector_alloc_holder<std::allocator<int>, boost::container::container_detail::integral_constant<unsigned int, 1u> >::vector_alloc_holder<std::allocator<int> >(std::allocator<int> const&, unsigned long) (vector.hpp:351)
==15591==    by 0x401007: boost::container::vector<int, std::allocator<int> >::vector(boost::container::vector<int, std::allocator<int> > const&) (vector.hpp:732)
==15591==    by 0x400F6C: boost::container::vector<int, std::allocator<int> >::vector(boost::container::vector<int, std::allocator<int> > const&) (vector.hpp:737)
==15591==    by 0x400EBB: main (test.cpp:10)
==15591== 
==15591== LEAK SUMMARY:
==15591==    definitely lost: 0 bytes in 1 blocks
==15591==    indirectly lost: 0 bytes in 0 blocks
==15591==      possibly lost: 0 bytes in 0 blocks
==15591==    still reachable: 0 bytes in 0 blocks
==15591==         suppressed: 0 bytes in 0 blocks
==15591== 
==15591== For counts of detected and suppressed errors, rerun with: -v
==15591== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 2 from 2)

I suspect that

   ~vector_alloc_holder() BOOST_CONTAINER_NOEXCEPT
   {
      if(this->m_capacity){
         this->alloc().deallocate(this->m_start, this->m_capacity);
      }
   }

should be

   ~vector_alloc_holder() BOOST_CONTAINER_NOEXCEPT
   {
      if(this->m_start){
         this->alloc().deallocate(this->m_start, this->m_capacity);
      }
   }

(not tested).

[Ion Gaztañaga]

Thanks for the report, it's a duplicate of #9166 which is fixed on trunk and release branches for Boost 1.55.