/usr/share/app-install/desktop/libfm-tools:libfm-pref-apps.desktop is in app-install-data 15.10.
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 8 9 10 11 12 13 14 15 | [Desktop Entry]
X-AppInstall-Package=libfm-tools
X-AppInstall-Popcon=4
X-AppInstall-Section=universe
Type=Application
Name=Preferred Applications
Comment=Select applications called on click on Web link or e-mail address
Icon=preferences-desktop
Exec=libfm-pref-apps
StartupNotify=true
Categories=Settings;DesktopSettings;X-LXDE-Settings;GTK;
NotShowIn=GNOME;XFCE;KDE;
X-Ubuntu-Gettext-Domain=app-install-data
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