Matching Java WM_CLASS or matching two WM_CLASS values

[Alessandro Crismani <alessandro crismani gmail com>]

Hi everybody,

I have a problem with a Java application that sets its WM_CLASS value to
either "wm-class-a" or "wm-class-b" (the two real ones are garbage, e.g.
java-lang-thread). The application is beyond my control and I can't
modify it for setting a saner WM_CLASS.

I can install the desktop file of the application as:
/usr/share/applications/wm-class-a.desktop,
and it will match instances having a WM_CLASS value of wm-class-a, or
as:
/usr/share/applications/wm-class-b.desktop,
and it will match instances having a WM_CLASS value of wm-class-b.

Neither solution is really good since I get a mis-match almost half of
the times.

I considered installing both files and adding a NoDisplay=true to one of
them, but then if I pin the one that is shown to the Dash, and the one
that spawns is the other one I still get two icons.

The question is, how can I match both instances with a single desktop
file? Is it possible? Can I somehow tell Gnome Shell that both WM_CLASS
values should match a particular desktop file?

Thanks a lot,
Alessandro