Submitted by: @AlexPeshkoff

The loop in merge.cpp:72 expects the `in` buffer to eventually contain either isc_info_end, isc_info_truncated or isc_info_implementation, and will otherwise read out of buffer bounds with good chance for access violation.

With correctly working providers chances to get that error are very low, but it can happen in case of bug in provider (on server) or malware server replacement (on client).

Commits: ea6dc2a f88c95a