First of all: no I'm not to lazy to search in google. I already tried a lot of things and that what all say should work does not work for me.

I have manjaro with gnome shell 3.18.1 installed. Inside gnome I have installed dash-to-dock extension. I have at least two java-applications: yEd and phpstorm. Both have the WM_CLASS sun-awt-X11-XFramePeer and a second WM_CLASS (jetbrains-phpstorm for phpstorm, yed I don't remember).

The Java version I'm using is the latest from oracle:

~# java -version
java version "1.8.0_66"

yEd and phpstorm are both installed via yaourt and it seems the desktop files are generated correctly. But anyway the only way I got the second icon from phpstorm removed (only phpstorm is in favs.) is by setting StartupWMClass=sun-awt-X11-XFramePeer. But then yEd is shown in the same starter.

I also tried to add both: StartupWMClass=sun-awt-X11-XFramePeer,jetbrains-phpstorm but of course, that does not work too...

I found a lot of articles to set the class correctly but jetbrains-phpstorm does not work (it was this before and xprop WM_CLASS shows this class too).

Is there something else that I'm missing?

  • have you checked this link
    – user137124
    Nov 13, 2015 at 17:11

1 Answer 1


I see this also when using Java based apps.

I have tracked this issue down to Java not null terminating the WM_CLASS string. Mutter seems to return this invalid string as a result and gnome-shell uses this invalid string for matching the application name which obviously fails.

It is a bug in Java as the WM_CLASS string is supposed to be null terminated. I'm not sure what changed in mutter to expose this issue as it worked previously.


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