[xmonad] XMonad 0.10 only matches on last className?

Joseph Garvin joseph.h.garvin at gmail.com
Sun Sep 23 06:08:15 CEST 2012

On Sat, Sep 22, 2012 at 10:30 AM, Brandon Allbery <allbery.b at gmail.com> wrote:
> On Sat, Sep 22, 2012 at 11:25 AM, Joseph Garvin <joseph.h.garvin at gmail.com>
> wrote:
>> If I run xprop on my emacs I see this:
>> WM_CLASS(STRING) = "emacs", "Emacs23"
> You might want to read X11 documentation.  WM_CLASS is always a two-element
> list; the first string is appName aka resource name, and the second is
> className.  This has been true since X11R4 introduced WM_CLASS.

Ah, that makes sense. I must have gotten lucky with apps being named
the same as their class in the past, it always seemed to be matching
against any of the strings in there for me (I've never known the
actual purpose of WM_CLASS, I just learned to run xprop to find it for
matching years ago back when I used Sawfish instead of xmonad).

> xmonad has used them this way since at least 0.2.

The upgrade to xmonad 0.10 was due to Ubuntu upgrade, so emacs
changing it's WM_CLASS is what actually cause the breakage.


Joe G.

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