/usr/share/doc/libpth-dev/changelog.Debian.gz is in libpth-dev 2.0.7-20.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libpth-dev/../libpth20/changelog.Debian.gz
/usr/share/doc/libpth-dev/../libpth20/changelog.Debian.gz