/usr/share/doc/mapserver-bin/changelog.Debian.gz is in mapserver-bin 6.4.1-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/mapserver-bin/../libmapserver1/changelog.Debian.gz
/usr/share/doc/mapserver-bin/../libmapserver1/changelog.Debian.gz