/usr/share/doc/libherwig59-2-dev/changelog.Debian.gz is in libherwig59-2-dev 20061220+dfsg3-3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libherwig59-2-dev/../libpdflib804-2-dev/changelog.Debian.gz