strange problem here :
xprop outputs for recoll window :
WM_CLASS(STRING) = "recoll", "Recoll"
but, when I set in ~/.icewm/winoptions or /usr/share/icewm/winoptions :
nothing happens, still the red X as icon for recoll window.
As a test, I replaced in winoptions recoll.icon by zim.icon : it works,
zim gets /usr/share/icons/hicolor/48x48/apps/recoll.png as icon.
So it looks like icewm as some problem recognizing name and class only
for recoll window.
Any idea how to solve it ?