Exit gracefully in case of corrupted filters (Closes issue #782)
int compiler_set_root(struct block *blk)
{
   BUG_IF(blk == NULL);
   tree_root = blk;
   return E_SUCCESS;
}

int compiler_set_root(struct block *blk)
{
   BUG_IF(blk == NULL);
   tree_root = blk;
   return E_SUCCESS;
}
