filesystem::path::iterator inconsistency with multiple leading separators

[Stefan Große Pawig <boost@…>]

Iterating backwards through a filesystem::path does not terminate at path::begin() if the path starts with several leading directory separators.

For example:

#include <boost/filesystem.hpp>
#include <iostream>

int main()
{
  boost::filesystem::path p("/////foo");

  boost::filesystem::path::iterator i = p.begin();
  ++i;
  --i;
  std::cout << ((i == p.begin()) ? "same" : "different") << std::endl;
}

Expected output: same
Actual output: different

Looking at the source (filesystem/src/path.cpp), it seems that in path::begin() the iterator's m_pos member is set to the position of the last leading directory separator.

During backward iteration, m_pos is set to 0, though, so the iterator comparison (which involves comparing the m_pos members) yields false.