diff --git a/src/net_processing.cpp b/src/net_processing.cpp index 16b4735e5ef..7354eb57e90 100644 --- a/src/net_processing.cpp +++ b/src/net_processing.cpp @@ -1406,11 +1406,13 @@ void PeerManagerImpl::FindNextBlocksToDownload(const Peer& peer, unsigned int co return; } - // When we sync with AssumeUtxo and discover the snapshot is not in the peer's best chain, abort: - // We can't reorg to this chain due to missing undo data until the background sync has finished, + // When syncing with AssumeUtxo and the snapshot has not yet been validated, + // abort downloading blocks from peers that don't have the snapshot block in their best chain. + // We can't reorg to this chain due to missing undo data until validation completes, // so downloading blocks from it would be futile. const CBlockIndex* snap_base{m_chainman.CurrentChainstate().SnapshotBase()}; - if (snap_base && state->pindexBestKnownBlock->GetAncestor(snap_base->nHeight) != snap_base) { + if (snap_base && m_chainman.CurrentChainstate().m_assumeutxo == Assumeutxo::UNVALIDATED && + state->pindexBestKnownBlock->GetAncestor(snap_base->nHeight) != snap_base) { LogDebug(BCLog::NET, "Not downloading blocks from peer=%d, which doesn't have the snapshot block in its best chain.\n", peer.m_id); return; } diff --git a/test/functional/feature_assumeutxo.py b/test/functional/feature_assumeutxo.py index 20ebd823d13..7420dfe02a0 100755 --- a/test/functional/feature_assumeutxo.py +++ b/test/functional/feature_assumeutxo.py @@ -347,6 +347,29 @@ class AssumeutxoTest(BitcoinTestFramework): assert 'NETWORK' in ibd_node.getpeerinfo()[0]['servicesnames'] self.sync_blocks(nodes=(ibd_node, snapshot_node)) + def test_sync_to_most_work_chain_after_background_validation(self): + """ + After background validation completes, node should be able + to download and process blocks from peers without the snapshot block in their chain. + """ + self.log.info("Testing sync to the most-work chain without the snapshot block after background validation") + + forking_node = self.nodes[0] + snapshot_node = self.nodes[2] # Has already completed background validation + + self.log.info("Forking node switches to an alternative chain that forks one block before the snapshot block") + fork_point = SNAPSHOT_BASE_HEIGHT - 1 + forking_node_old_height = forking_node.getblockcount() + forking_node_old_chainwork = int(forking_node.getblockchaininfo()['chainwork'], 16) + forking_node.invalidateblock(forking_node.getblockhash(fork_point + 1)) + + self.log.info("Mine one more block than original chain to make the new chain have most work") + self.generate(forking_node, nblocks=(forking_node_old_height - fork_point) + 1, sync_fun=self.no_op) + assert int(forking_node.getblockchaininfo()['chainwork'], 16) > forking_node_old_chainwork + + self.log.info("Snapshot node should reorg to the most-work chain without the snapshot block") + self.sync_blocks(nodes=(snapshot_node, forking_node)) + def assert_only_network_limited_service(self, node): node_services = node.getnetworkinfo()['localservicesnames'] assert 'NETWORK' not in node_services @@ -775,6 +798,8 @@ class AssumeutxoTest(BitcoinTestFramework): # The following test cleans node2 and node3 chain directories. self.test_sync_from_assumeutxo_node(snapshot=dump_output) + self.test_sync_to_most_work_chain_after_background_validation() + @dataclass class Block: hash: str