Ticket #4576: filesystem-buffer-size-problem.cpp

#define BOOST_FILESYSTEM_VERSION 3

#include <iostream>
#include <cassert>
#include <cstring>
#include <algorithm>
#include <boost/filesystem.hpp>

int main()
{
    // EXAMPLE 1: buffer size known at compile time
    char buffer1[255] = "./foo";
    boost::filesystem::path p1(buffer1);

    // size() should be 5 (for "./foo") but is actually 254 because
    // the entire buffer except for the final character was added to
    // the path!
    //
    // The expected behavior would be to stop at the first
    // NULL-terminator.

    std::cout << "p1.string().size() is " << p1.string().size() << std::endl;
    // output: p1.string().size() is 254

    // EXAMPLE 2: dynamically allocated buffer
    char *buffer2 = new char[255];
    std::fill(buffer2, buffer2 + 255, '\0');
    strcpy(buffer2, "./foo");

    // buffer2 is now identical to buffer1
    assert(std::equal(buffer1, buffer1 + 255, buffer2));

    // ...but boost::filesystem treats it differently.
    boost::filesystem::path p2(buffer2);

    std::cout << "p2.string().size() is " << p2.string().size() << std::endl;
    // output: p1.string().size() is 5

    delete [] buffer2;
}