Right now it checks the title controls layout that is typically set only by gtk based DEs and KDE matching the GNOME's and Pantheon's defaults.
There are more and more reports about window manager not to supporting both tray and minimization out of the box and title controls layout seem to typically be either unset or set to nothing leaving users with no way to run tdesktop with no window open.
Currently the app id hash is generated from workdir path only when it's set explicitly and that's for a good reason: the default workdir could be changed (e.g. by creating a TelegramForcePortable) and app id would change what would result in a duplicate .desktop created.
The current code has the possibility of having duplicate .desktop files, too, as it happened, but by specifying -workdir to the same directory as the default one.
There's now a check that ensures the specified workdir is really custom so those duplicate launchers could be removed what should really stabilize the hash.
Working dir not set leads to unrelevant instance being launched with unrelevant bus name and entire launchf fails.
D-Bus service files also don't need backslash escaping unlike the .desktop files.
The Qt documentation says:
This is the file name, without the full path or the trailing ".desktop" extension of the desktop entry that represents this application according to the freedesktop desktop entry specification.
Qt 6.5.2 also automatically fixes it breaking all the current tdesktop and desktop-app usage expecting the file extension.
Desktop App Toolkit uses GLib as the D-Bus library for quite long time, but GLib is not only a D-Bus library, it's more a basic library providing native Linux APIs implementing various specs. The situation right now is that DESKTOP_APP_DISABLE_DBUS_INTEGRATION disables not only D-Bus code but all the native API integration such as MIME handling or .desktop file parsing. In other words, the option disables native Linux APIs on Linux what is absurd and doesn't have any sense.
