Method reorg_back

test/functional/feature_pruning.py:230–271

(self)

        assert_greater_than(550, usage)

    def reorg_back(self):
        # Verify that a block on the old main chain fork has been pruned away
        assert_raises_rpc_error(-1, "Block not available (pruned data)", self.nodes[2].getblock, self.forkhash)
        with self.nodes[2].assert_debug_log(expected_msgs=['block verification stopping at height', '(pruning, no data)']):
            self.nodes[2].verifychain(checklevel=4, nblocks=0)
        self.log.info(f"Will need to redownload block {self.forkheight}")

        # Verify that we have enough history to reorg back to the fork point
        # Although this is more than 288 blocks, because this chain was written more recently
        # and only its other 299 small and 220 large blocks are in the block files after it,
        # it is expected to still be retained
        self.nodes[2].getblock(self.nodes[2].getblockhash(self.forkheight))

        first_reorg_height = self.nodes[2].getblockcount()
        curchainhash = self.nodes[2].getblockhash(self.mainchainheight)
        self.nodes[2].invalidateblock(curchainhash)
        goalbestheight = self.mainchainheight
        goalbesthash = self.mainchainhash2

        # As of 0.10 the current block download logic is not able to reorg to the original chain created in
        # create_chain_with_stale_blocks because it doesn't know of any peer that's on that chain from which to
        # redownload its missing blocks.
        # Invalidate the reorg_test chain in node 0 as well, it can successfully switch to the original chain
        # because it has all the block data.
        # However it must mine enough blocks to have a more work chain than the reorg_test chain in order
        # to trigger node 2's block download logic.
        # At this point node 2 is within 288 blocks of the fork point so it will preserve its ability to reorg
        if self.nodes[2].getblockcount() < self.mainchainheight:
            blocks_to_mine = first_reorg_height + 1 - self.mainchainheight
            self.log.info(f"Rewind node 0 to prev main chain to mine longer chain to trigger redownload. Blocks needed: {blocks_to_mine}")
            self.nodes[0].invalidateblock(curchainhash)
            assert_equal(self.nodes[0].getblockcount(), self.mainchainheight)
            assert_equal(self.nodes[0].getbestblockhash(), self.mainchainhash2)
            goalbesthash = self.generate(self.nodes[0], blocks_to_mine, sync_fun=self.no_op)[-1]
            goalbestheight = first_reorg_height + 1

        self.log.info("Verify node 2 reorged back to the main chain, some blocks of which it had to redownload")
        # Wait for Node 2 to reorg to proper height
        self.wait_until(lambda: self.nodes[2].getblockcount() >= goalbestheight, timeout=900)
        assert_equal(self.nodes[2].getbestblockhash(), goalbesthash)
        # Verify we can now have the data for a block previously pruned
        assert_equal(self.nodes[2].getblock(self.forkhash)["height"], self.forkheight)

    def manual_test(self, node_number, use_timestamp):
        # at this point, node has 995 blocks and has not yet run in prune mode