Anyway, what is the purpose of setting MWM_DECOR_BORDER to borderless window (style is WS_CLIPSIBLINGS only)? KDE, XFCE, fluxbox work OK without it.
If you mean the following line in dlls/winex11.drv/window.c,X11DRV_set_wm_hints()
else if (!(style & (WS_CHILD|WS_POPUP))) mwm_hints.decorations |=
MWM_DECOR_BORDER;
then you can always send a patch with an explanation why it's needed.
Of course, I can send a patch, which just removes this line with some explanations (referring to winamp), but I'm afraid it may break something. Since original patch introduced this code, there is an application which depends on this. But that original patch does not contain any hint, so I ask the list in hope somebody might know the reason.
-- Kirill