QT 4.8 Build qdirectfb fail

Compiling Qt 4.8.0 with DirectFb ( -plugin-gfx-directfb -qt-gfx-linuxfb ) and:
DEFINES += QT_NO_DIRECTFB_WM
DEFINES += QT_NO_DIRECTFB_LAYER

Cause the following error:
qdirectfbwindowsurface.cpp: In member function 'virtual QByteArray QDirectFBWindowSurface::permanentState() const':
qdirectfbwindowsurface.cpp:294:9: error: 'dfbWindow' was not declared in this scope

Tha cause is because:
qdirectfbwindowsurface.h define dfbWindow variable only if QT_DIRECTFB_WM is definded, but the method QDirectFBWindowSurface::permanentState() (qdirectfbwindowsurface.cpp) use that symbol also if QT_DIRECTFB_WM is not defined...in this case the symbol doesn't exists!
The problem is aslo for
void QDirectFBWindowSurface::setPermanentState(const QByteArray &state).
I guess that the problem is due to a bugfix of 4.7.x that doesn't take care about QT_NO_DIRECTFB_WM, QT_NO_DIRECTFB_LAYER configurations.