/usr/share/doc/liballegro-physfs5.0/changelog.Debian.gz is in liballegro-physfs5.0 2:5.0.10-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/liballegro-physfs5.0/../liballegro5.0/changelog.Debian.gz