VBF_STATIC
if ((vb->vb_flags & VBF_STATIC) == 0) {
old = vb->vb_flags & VBF_STATIC ? NULL : vb->vb_buffer;
oldrows = vb->vb_flags & VBF_STATIC ? NULL : vb->vb_rows;
vb->vb_flags &= ~VBF_STATIC;
.vb_flags = VBF_STATIC,