/usr/share/xsessions/mythbuntu.desktop is in mythbuntu-default-settings 1.11.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 | [Desktop Entry]
Encoding=UTF-8
Name=Mythbuntu Session
Comment=Use this session to boot into mythbuntu.
Exec=/usr/share/mythbuntu/session.sh
Icon=
Type=Application
|