These files were pulled from the 1.6.3 release tarball.
This new version builds against OpenSSL version 1.1 which will be
the default in the new Debian Stable which is due to be released
RealSoonNow (tm).
Due to a bug in unbound, we were passing a string containing a null
character to ub_ctx_resolvconf and ub_ctx_hosts rather than a NULL
pointer. On *nix this wasn't causing headache, but on Windows this was
causing unbound to not correctly load DNS settings from the OS.
Note on the bug: in a Windows-specific code branch in the function
ub_ctx_hosts(), if the hosts file specified was a NULL pointer, a call
to getenv() was stored in a local char* and later freed. This is
incorrect, as we do not own that data, and caused the program to crash.