/usr/share/doc/gir1.2-mate-desktop/changelog.Debian.gz is in gir1.2-mate-desktop 1.20.1-2ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/gir1.2-mate-desktop/../libmate-desktop-2-17/changelog.Debian.gz