[Libvncserver-common] rfbMakeRichCursorFromXCursor crash

Hello,

i get a crash in rfbMakeRichCursorFromXCursor

#0  0xf65fbef0 in rfbMakeRichCursorFromXCursor () from /usr/lib/libvncserver.so.1
#1  0xf65fc370 in rfbSendCursorShape () from /usr/lib/libvncserver.so.1
#2  0xf65ee034 in rfbSendFramebufferUpdate () from /usr/lib/libvncserver.so.1
#3  0xf65e8440 in rfbUpdateClient () from /usr/lib/libvncserver.so.1
#4  0xf65e84d4 in rfbProcessEvents () from /usr/lib/libvncserver.so.1
#5  0x00147f00 in processClientEvents ()

After add some logging I see, that "cursor->source" is NULL.
So it crash at line
if(cursor->source[ j * w + i / 8] & bit)

Is this a knowing bug ?
Exists there a bug fix ?

Thanks & best regards
  Johann