/usr/share/doc/libqt4-core/changelog.Debian.gz is in libqt4-core 4:4.8.5+git192-g085f851+dfsg-2ubuntu4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libqt4-core/../libqt4-dbus/changelog.Debian.gz