It may be useful to create AppVM-specific menu entries in AppVM itself.
It may be an application installed there (in /usr/local, or using snap
QubesOS/qubes-issues#2766), but it may be also some user custom
shortcut.
To support this, dom0 will accept menu entries also from
TemplateBasedVMs. But to avoid duplicates, qubes.GetAppmenus service
should send only menu entries actually stored in that VM, not inherited
from its template. To distingush them, first check what type of
persistence this VM has (from qubesdb-read /qubes-vm-persistence). If
it's rw-only, send only entries stored on /rw.
To make it more robust, use $XDG_DATA_DIRS and $XDG_DATA_HOME to
discover directories, instead of looking only for
/usr/{,local/}share/applications. This makes snap and flatpak handled
for free.
FixesQubesOS/qubes-issues#4152
According to Desktop Entry Specification:
NoDisplay means "this application exists, but don't display it in the
menus". This can be useful to e.g. associate this application with MIME
types, so that it gets launched from a file manager (or other apps),
without having a menu entry for it (there are tons of good reasons
for this, including e.g. the netscape -remote, or kfmclient openURL kind
of stuff).
Apparently over half of desktop files in default Fedora template have
NoDisplay=true...
FixesQubesOS/qubes-issues#1348
Instead of directly using Exec= line, parse the file (at the launch
time) with Gio library. The main reason for this change is to handle
Terminal= option, but generally this approach should be more
bulletproof, especially when some fancy options are present in desktop
files.