1 files changed, 115 insertions, 0 deletions
diff --git a/test/functional/preciousblock.py b/test/functional/preciousblock.py
new file mode 100755
index 0000000000..30b0b5a301
--- /dev/null
+++ b/test/functional/preciousblock.py
@@ -0,0 +1,115 @@
+#!/usr/bin/env python3
+# Copyright (c) 2015-2016 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Test the preciousblock RPC."""
+
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import (
+    assert_equal,
+    connect_nodes_bi,
+    sync_chain,
+    sync_blocks,
+)
+
+def unidirectional_node_sync_via_rpc(node_src, node_dest):
+    blocks_to_copy = []
+    blockhash = node_src.getbestblockhash()
+    while True:
+        try:
+            assert(len(node_dest.getblock(blockhash, False)) > 0)
+            break
+        except:
+            blocks_to_copy.append(blockhash)
+            blockhash = node_src.getblockheader(blockhash, True)['previousblockhash']
+    blocks_to_copy.reverse()
+    for blockhash in blocks_to_copy:
+        blockdata = node_src.getblock(blockhash, False)
+        assert(node_dest.submitblock(blockdata) in (None, 'inconclusive'))
+
+def node_sync_via_rpc(nodes):
+    for node_src in nodes:
+        for node_dest in nodes:
+            if node_src is node_dest:
+                continue
+            unidirectional_node_sync_via_rpc(node_src, node_dest)
+
+class PreciousTest(BitcoinTestFramework):
+    def __init__(self):
+        super().__init__()
+        self.setup_clean_chain = True
+        self.num_nodes = 3
+
+    def setup_network(self):
+        self.nodes = self.setup_nodes()
+
+    def run_test(self):
+        self.log.info("Ensure submitblock can in principle reorg to a competing chain")
+        self.nodes[0].generate(1)
+        assert_equal(self.nodes[0].getblockcount(), 1)
+        (hashY, hashZ) = self.nodes[1].generate(2)
+        assert_equal(self.nodes[1].getblockcount(), 2)
+        node_sync_via_rpc(self.nodes[0:3])
+        assert_equal(self.nodes[0].getbestblockhash(), hashZ)
+
+        self.log.info("Mine blocks A-B-C on Node 0")
+        (hashA, hashB, hashC) = self.nodes[0].generate(3)
+        assert_equal(self.nodes[0].getblockcount(), 5)
+        self.log.info("Mine competing blocks E-F-G on Node 1")
+        (hashE, hashF, hashG) = self.nodes[1].generate(3)
+        assert_equal(self.nodes[1].getblockcount(), 5)
+        assert(hashC != hashG)
+        self.log.info("Connect nodes and check no reorg occurs")
+        # Submit competing blocks via RPC so any reorg should occur before we proceed (no way to wait on inaction for p2p sync)
+        node_sync_via_rpc(self.nodes[0:2])
+        connect_nodes_bi(self.nodes,0,1)
+        assert_equal(self.nodes[0].getbestblockhash(), hashC)
+        assert_equal(self.nodes[1].getbestblockhash(), hashG)
+        self.log.info("Make Node0 prefer block G")
+        self.nodes[0].preciousblock(hashG)
+        assert_equal(self.nodes[0].getbestblockhash(), hashG)
+        self.log.info("Make Node0 prefer block C again")
+        self.nodes[0].preciousblock(hashC)
+        assert_equal(self.nodes[0].getbestblockhash(), hashC)
+        self.log.info("Make Node1 prefer block C")
+        self.nodes[1].preciousblock(hashC)
+        sync_chain(self.nodes[0:2]) # wait because node 1 may not have downloaded hashC
+        assert_equal(self.nodes[1].getbestblockhash(), hashC)
+        self.log.info("Make Node1 prefer block G again")
+        self.nodes[1].preciousblock(hashG)
+        assert_equal(self.nodes[1].getbestblockhash(), hashG)
+        self.log.info("Make Node0 prefer block G again")
+        self.nodes[0].preciousblock(hashG)
+        assert_equal(self.nodes[0].getbestblockhash(), hashG)
+        self.log.info("Make Node1 prefer block C again")
+        self.nodes[1].preciousblock(hashC)
+        assert_equal(self.nodes[1].getbestblockhash(), hashC)
+        self.log.info("Mine another block (E-F-G-)H on Node 0 and reorg Node 1")
+        self.nodes[0].generate(1)
+        assert_equal(self.nodes[0].getblockcount(), 6)
+        sync_blocks(self.nodes[0:2])
+        hashH = self.nodes[0].getbestblockhash()
+        assert_equal(self.nodes[1].getbestblockhash(), hashH)
+        self.log.info("Node1 should not be able to prefer block C anymore")
+        self.nodes[1].preciousblock(hashC)
+        assert_equal(self.nodes[1].getbestblockhash(), hashH)
+        self.log.info("Mine competing blocks I-J-K-L on Node 2")
+        self.nodes[2].generate(4)
+        assert_equal(self.nodes[2].getblockcount(), 6)
+        hashL = self.nodes[2].getbestblockhash()
+        self.log.info("Connect nodes and check no reorg occurs")
+        node_sync_via_rpc(self.nodes[1:3])
+        connect_nodes_bi(self.nodes,1,2)
+        connect_nodes_bi(self.nodes,0,2)
+        assert_equal(self.nodes[0].getbestblockhash(), hashH)
+        assert_equal(self.nodes[1].getbestblockhash(), hashH)
+        assert_equal(self.nodes[2].getbestblockhash(), hashL)
+        self.log.info("Make Node1 prefer block L")
+        self.nodes[1].preciousblock(hashL)
+        assert_equal(self.nodes[1].getbestblockhash(), hashL)
+        self.log.info("Make Node2 prefer block H")
+        self.nodes[2].preciousblock(hashH)
+        assert_equal(self.nodes[2].getbestblockhash(), hashH)
+
+if __name__ == '__main__':
+    PreciousTest().main()