/usr/share/doc/kdegraphics-mobipocket/changelog.Debian.gz is in kdegraphics-mobipocket 4:15.12.3-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/kdegraphics-mobipocket/../libqmobipocket1/changelog.Debian.gz