/usr/share/doc/gir1.2-gst-plugins-bad-1.0/changelog.Debian.gz is in gir1.2-gst-plugins-bad-1.0 1.8.0-1ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/gir1.2-gst-plugins-bad-1.0/../libgstreamer-plugins-bad1.0-0/changelog.Debian.gz