[tests] check v0.17.1 and v0.18.1 backwards compatibility

4 files changed, 98 insertions, 5 deletions

diff --git a/test/functional/feature_backwards_compatibility.py b/test/functional/feature_backwards_compatibility.py
new file mode 100755
index 0000000000..452b553374
--- /dev/null
+++ b/test/functional/feature_backwards_compatibility.py
@@ -0,0 +1,78 @@
+#!/usr/bin/env python3
+# Copyright (c) 2018-2019 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Backwards compatibility functional test
+
+Test various backwards compatibility scenarios. Download the previous node binaries:
+
+contrib/devtools/previous_release.sh -b v0.18.1 v0.17.1
+
+Due to RPC changes introduced in various versions the below tests
+won't work for older versions without some patches or workarounds.
+
+Use only the latest patch version of each release, unless a test specifically
+needs an older patch version.
+"""
+
+import os
+
+from test_framework.test_framework import BitcoinTestFramework, SkipTest
+
+from test_framework.util import (
+    assert_equal,
+    sync_blocks
+)
+
+class BackwardsCompatibilityTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.setup_clean_chain = True
+        self.num_nodes = 4
+        # Add new version after each release:
+        self.extra_args = [
+            [], # Pre-release: use to mine blocks
+            [], # Pre-release: use to receive coins, swap wallets, etc
+            [], # v0.18.1
+            [] # v0.17.1
+        ]
+
+    def setup_nodes(self):
+        if os.getenv("TEST_PREVIOUS_RELEASES") == "false":
+            raise SkipTest("backwards compatibility tests")
+
+        releases_path = os.getenv("PREVIOUS_RELEASES_DIR") or os.getcwd() + "/releases"
+        if not os.path.isdir(releases_path):
+            if os.getenv("TEST_PREVIOUS_RELEASES") == "true":
+                raise AssertionError("TEST_PREVIOUS_RELEASES=1 but releases missing: " + releases_path)
+            raise SkipTest("This test requires binaries for previous releases")
+
+        self.add_nodes(self.num_nodes, extra_args=self.extra_args, versions=[
+            None,
+            None,
+            180100,
+            170100
+        ], binary=[
+            self.options.bitcoind,
+            self.options.bitcoind,
+            releases_path + "/v0.18.1/bin/bitcoind",
+            releases_path + "/v0.17.1/bin/bitcoind"
+        ], binary_cli=[
+            self.options.bitcoincli,
+            self.options.bitcoincli,
+            releases_path + "/v0.18.1/bin/bitcoin-cli",
+            releases_path + "/v0.17.1/bin/bitcoin-cli"
+        ])
+
+        self.start_nodes()
+
+    def run_test(self):
+        self.nodes[0].generate(101)
+
+        sync_blocks(self.nodes)
+
+        # Sanity check the test framework:
+        res = self.nodes[self.num_nodes - 1].getblockchaininfo()
+        assert_equal(res['blocks'], 101)
+
+if __name__ == '__main__':
+    BackwardsCompatibilityTest().main()
diff --git a/test/functional/test_framework/test_framework.py b/test/functional/test_framework/test_framework.py
index da92c6325a..e36fb350c6 100755
--- a/test/functional/test_framework/test_framework.py
+++ b/test/functional/test_framework/test_framework.py
@@ -369,7 +369,7 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
 
     # Public helper methods. These can be accessed by the subclass test scripts.
 
-    def add_nodes(self, num_nodes, extra_args=None, *, rpchost=None, binary=None):
+    def add_nodes(self, num_nodes, extra_args=None, *, rpchost=None, binary=None, binary_cli=None, versions=None):
         """Instantiate TestNode objects.
 
         Should only be called once after the nodes have been specified in
@@ -380,11 +380,17 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
             extra_confs = [[]] * num_nodes
         if extra_args is None:
             extra_args = [[]] * num_nodes
+        if versions is None:
+            versions = [None] * num_nodes
         if binary is None:
             binary = [self.options.bitcoind] * num_nodes
+        if binary_cli is None:
+            binary_cli = [self.options.bitcoincli] * num_nodes
         assert_equal(len(extra_confs), num_nodes)
         assert_equal(len(extra_args), num_nodes)
+        assert_equal(len(versions), num_nodes)
         assert_equal(len(binary), num_nodes)
+        assert_equal(len(binary_cli), num_nodes)
         for i in range(num_nodes):
             self.nodes.append(TestNode(
                 i,
@@ -393,7 +399,8 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
                 rpchost=rpchost,
                 timewait=self.rpc_timeout,
                 bitcoind=binary[i],
-                bitcoin_cli=self.options.bitcoincli,
+                bitcoin_cli=binary_cli[i],
+                version=versions[i],
                 coverage_dir=self.options.coveragedir,
                 cwd=self.options.tmpdir,
                 extra_conf=extra_confs[i],
diff --git a/test/functional/test_framework/test_node.py b/test/functional/test_framework/test_node.py
index 0742dbe617..c7559ac7c8 100755
--- a/test/functional/test_framework/test_node.py
+++ b/test/functional/test_framework/test_node.py
@@ -60,7 +60,7 @@ class TestNode():
     To make things easier for the test writer, any unrecognised messages will
     be dispatched to the RPC connection."""
 
-    def __init__(self, i, datadir, *, chain, rpchost, timewait, bitcoind, bitcoin_cli, coverage_dir, cwd, extra_conf=None, extra_args=None, use_cli=False, start_perf=False, use_valgrind=False):
+    def __init__(self, i, datadir, *, chain, rpchost, timewait, bitcoind, bitcoin_cli, coverage_dir, cwd, extra_conf=None, extra_args=None, use_cli=False, start_perf=False, use_valgrind=False, version=None):
         """
         Kwargs:
             start_perf (bool): If True, begin profiling the node with `perf` as soon as
@@ -84,6 +84,7 @@ class TestNode():
         # For those callers that need more flexibility, they can just set the args property directly.
         # Note that common args are set in the config file (see initialize_datadir)
         self.extra_args = extra_args
+        self.version = version
         # Configuration for logging is set as command-line args rather than in the bitcoin.conf file.
         # This means that starting a bitcoind using the temp dir to debug a failed test won't
         # spam debug.log.
@@ -91,7 +92,6 @@ class TestNode():
             self.binary,
             "-datadir=" + self.datadir,
             "-logtimemicros",
-            "-logthreadnames",
             "-debug",
             "-debugexclude=libevent",
             "-debugexclude=leveldb",
@@ -107,6 +107,9 @@ class TestNode():
                          "--gen-suppressions=all", "--exit-on-first-error=yes",
                          "--error-exitcode=1", "--quiet"] + self.args
 
+        if self.version is None or self.version >= 190000:
+            self.args.append("-logthreadnames")
+
         self.cli = TestNodeCLI(bitcoin_cli, self.datadir)
         self.use_cli = use_cli
         self.start_perf = start_perf
@@ -254,7 +257,11 @@ class TestNode():
             return
         self.log.debug("Stopping node")
         try:
-            self.stop(wait=wait)
+            # Do not use wait argument when testing older nodes, e.g. in feature_backwards_compatibility.py
+            if self.version is None or self.version >= 180000:
+                self.stop(wait=wait)
+            else:
+                self.stop()
         except http.client.CannotSendRequest:
             self.log.exception("Unable to stop node.")
 
diff --git a/test/functional/test_runner.py b/test/functional/test_runner.py
index 8b527bcff0..ea8a340081 100755
--- a/test/functional/test_runner.py
+++ b/test/functional/test_runner.py
@@ -158,6 +158,7 @@ BASE_SCRIPTS = [
     'feature_assumevalid.py',
     'example_test.py',
     'wallet_txn_doublespend.py',
+    'feature_backwards_compatibility.py',
     'wallet_txn_clone.py --mineblock',
     'feature_notifications.py',
     'rpc_getblockfilter.py',