/usr/share/gdm/greeter/applications/mime-dummy-handler.desktop is in gdm3 3.28.0-0ubuntu1.
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]
Type=Application
Name=Dummy URI Handler
Exec=true %U
Terminal=false
StartupNotify=false
X-Ubuntu-Gettext-Domain=gdm
|