program_option::environment_iterator moves past terminating NULL pointer

[abel@…]

The get() method increments m_environment outside of the else scope:

void get() {

if (*m_environment == 0)

found_eof();

else {

std::string s(*m_environment);

std::string::size_type n = s.find('=');

assert(n != s.npos);

value().first = s.substr(0, n);

value().second = s.substr(n+1);

}

++m_environment;

}

This means the iterator will move past the terminating pointer. A simple fix seems to include the increment in the else's scope.

[Vladimir Prus]

Fixed in ​https://github.com/boostorg/program_options/commit/f50b02750a7b17ec6a149c0264bef5727a8df1f6

Did you see any practical issues as result of this?

[abel@…]

No, I did not. I noticed it when working on a dirty hack to get program_options to work with c++0x using Windows' GetEnvironmentStrings where I consequently had to touch this routine.

A segmentation fault might obviously occur when other codes doesn't just use the pointer semantics as get() is public, but that's probably not what's considered a practical issue. Thanks for the quick response tho!