GApplication has accepted any valid bus name as an application ID since
before the time of D-Bus activation.  This includes bus names with '-'.
Several applications have even attempted support bus activation with
these names, going as far as installing D-Bus service files, without
realising that they are silently falling back to fork()/exec() on
account of the name containing a dash.

The reason for the problem is that D-Bus object paths cannot contain
dashes.  We solved this problem privately in an unspecified way inside
of GApplication but substituting '_' in this case, but never made this
part of the Desktop Entry Specification.

The fact that these apps with '-' in the desktop file names aren't
actually using D-Bus activation is beside the point: their intent here
was clear.  Let's avoid forcing them to rename their desktop files again
by simply accepting '-' in desktop file names and munging the path in
the way that GApplication did so historically.

T...