AIKIDO-2026-10453

TL;DR

The Reader::parse(std::istream&) overload read the stream into a local std::string, then forwarded pointers into that buffer to parse(const char*, const char*), which stored them in begin_ / end_. After parse returned, the local string was destroyed while the reader could still hold those pointers. Calling getFormattedErrorMessages() afterward could read freed memory. The fix reads the stream into the member document_ so the buffer lifetime matches the reader, consistent with parse(const std::string&).