Add validation for zero-length binary values about winreg HOT 2 CLOSED

Thank you for signaling that bug. I tried to reproduce it and I confirm that it is valid. I'll try to fix it when I have time.

The fix should be checking if dataSize is zero, and in such case just return an empty std::vector and skipping the second call to RegGetValue to get the content.

I also need to check the other potential points of code that may be affected by a similar problem.

Thanks again.

from winreg.

I think there is another (better?) way of fixing it: replacing the &data[0] with an invocation to the std::vector::data() member function:

    // Call RegGetValue for the second time to read the data content
    retCode = ::RegGetValueW(
        m_hKey,
        nullptr,    // no subkey
        valueName.c_str(),
        flags,
        nullptr,    // type not required
        // *** BUG: &data[0],   // output buffer
        // *** FIX: Invoke std::vector::data(), which works also for empty vectors:
        data.data(), // output buffer
        &dataSize
    );

from winreg.