def _test_waitforblockheight(self):
        self.log.info("Test waitforblockheight")
        node = self.nodes[0]
        node.add_p2p_connection(P2PInterface())

        current_height = node.getblock(node.getbestblockhash())['height']

        # Create a fork somewhere below our current height, invalidate the tip
        # of that fork, and then ensure that waitforblockheight still
        # works as expected.
        #
        # (Previously this was broken based on setting
        # `rpc/blockchain.cpp:latestblock` incorrectly.)
        #
        b20hash = node.getblockhash(20)
        b20 = node.getblock(b20hash)

        def solve_and_send_block(prevhash, height, time):
            b = create_block(prevhash, create_coinbase(height), time)
            b.solve()
            node.p2p.send_message(msg_block(b))
            node.p2p.sync_with_ping()
            return b

        b21f = solve_and_send_block(int(b20hash, 16), 21, b20['time'] + 1)
        b22f = solve_and_send_block(b21f.sha256, 22, b21f.nTime + 1)

        node.invalidateblock(b22f.hash)

        def assert_waitforheight(height, timeout=2):
            assert_equal(
                node.waitforblockheight(height=height, timeout=timeout)['height'],
                current_height)

        assert_waitforheight(0)
        assert_waitforheight(current_height - 1)
        assert_waitforheight(current_height)
        assert_waitforheight(current_height + 1)