Add RPC test of RewindBlockIndex

qa/pull-tester/rpc-tests.sh

@@ -54,6 +54,7 @@ testScripts=(
     'bip65-cltv-p2p.py'
     'bipdersig-p2p.py'
     'overwinter_peer_management.py'
+    'rewind_index.py'
 );
 testScriptsExt=(
     'getblocktemplate_longpoll.py'

qa/rpc-tests/rewind_index.py

@@ -0,0 +1,85 @@
+#!/usr/bin/env python2
+# Copyright (c) 2018 The Zcash developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import assert_equal, initialize_chain_clean, \
+    start_nodes, start_node, connect_nodes_bi, bitcoind_processes
+
+import time
+
+
+class RewindBlockIndexTest (BitcoinTestFramework):
+
+    def setup_chain(self):
+        print("Initializing test directory "+self.options.tmpdir)
+        initialize_chain_clean(self.options.tmpdir, 3)
+
+    def setup_network(self, split=False):
+        # Node 0 - Overwinter, then Sprout, then Overwinter again
+        # Node 1 - Sprout
+        # Node 2 - Overwinter
+        self.nodes = start_nodes(3, self.options.tmpdir, extra_args=[['-nuparams=5ba81b19:10'], [], ['-nuparams=5ba81b19:10']])
+        connect_nodes_bi(self.nodes,0,1)
+        connect_nodes_bi(self.nodes,1,2)
+        connect_nodes_bi(self.nodes,0,2)
+        self.is_network_split=False
+        self.sync_all()
+
+    def run_test (self):
+        # Bring all nodes to just before the activation block
+        print("Mining blocks...")
+        self.nodes[0].generate(8)
+        block9 = self.nodes[0].generate(1)[0]
+        self.sync_all()
+
+        assert_equal(self.nodes[0].getbestblockhash(), block9)
+        assert_equal(self.nodes[1].getbestblockhash(), block9)
+
+        print("Mining diverging blocks")
+        block10s = self.nodes[1].generate(1)[0]
+        block10o = self.nodes[2].generate(1)[0]
+        self.sync_all()
+
+        assert_equal(self.nodes[0].getbestblockhash(), block10o)
+        assert_equal(self.nodes[1].getbestblockhash(), block10s)
+        assert_equal(self.nodes[2].getbestblockhash(), block10o)
+
+        # Restart node 0 using Sprout instead of Overwinter
+        print("Switching node 0 from Overwinter to Sprout")
+        self.nodes[0].stop()
+        bitcoind_processes[0].wait()
+        self.nodes[0] = start_node(0,self.options.tmpdir)
+        connect_nodes_bi(self.nodes,0,1)
+        connect_nodes_bi(self.nodes,1,2)
+        connect_nodes_bi(self.nodes,0,2)
+
+        # Assume node 1 will send block10s to node 0 quickly
+        # (if we used self.sync_all() here and there was a bug, the test would hang)
+        time.sleep(2)
+
+        # Node 0 has rewound and is now on the Sprout chain
+        assert_equal(self.nodes[0].getblockcount(), 10)
+        assert_equal(self.nodes[0].getbestblockhash(), block10s)
+
+        # Restart node 0 using Overwinter instead of Sprout
+        print("Switching node 0 from Sprout to Overwinter")
+        self.nodes[0].stop()
+        bitcoind_processes[0].wait()
+        self.nodes[0] = start_node(0,self.options.tmpdir, extra_args=['-nuparams=5ba81b19:10'])
+        connect_nodes_bi(self.nodes,0,1)
+        connect_nodes_bi(self.nodes,1,2)
+        connect_nodes_bi(self.nodes,0,2)
+
+        # Assume node 2 will send block10o to node 0 quickly
+        # (if we used self.sync_all() here and there was a bug, the test would hang)
+        time.sleep(2)
+
+        # Node 0 has rewound and is now on the Overwinter chain again
+        assert_equal(self.nodes[0].getblockcount(), 10)
+        assert_equal(self.nodes[0].getbestblockhash(), block10o)
+
+
+if __name__ == '__main__':
+    RewindBlockIndexTest().main()