3 files changed, 79 insertions, 1 deletions
diff --git a/test/functional/test_framework/mininode.py b/test/functional/test_framework/mininode.py
index d5b1a90687..ccf767d357 100755
--- a/test/functional/test_framework/mininode.py
+++ b/test/functional/test_framework/mininode.py
@@ -179,7 +179,17 @@ class P2PConnection(asyncio.Protocol):
             raise IOError('Not connected')
         self._log_message("send", message)
         tmsg = self._build_message(message)
-        NetworkThread.network_event_loop.call_soon_threadsafe(lambda: self._transport and not self._transport.is_closing() and self._transport.write(tmsg))
+
+        def maybe_write():
+            if not self._transport:
+                return
+            # Python <3.4.4 does not have is_closing, so we have to check for
+            # its existence explicitly as long as Bitcoin Core supports all
+            # Python 3.4 versions.
+            if hasattr(self._transport, 'is_closing') and self._transport.is_closing():
+                return
+            self._transport.write(tmsg)
+        NetworkThread.network_event_loop.call_soon_threadsafe(maybe_write)
 
     # Class utility methods
 
diff --git a/test/functional/test_runner.py b/test/functional/test_runner.py
index 4c5acf69a9..d324cd9bba 100755
--- a/test/functional/test_runner.py
+++ b/test/functional/test_runner.py
@@ -105,6 +105,7 @@ BASE_SCRIPTS = [
     'rpc_users.py',
     'feature_proxy.py',
     'rpc_signrawtransaction.py',
+    'wallet_groups.py',
     'p2p_disconnect_ban.py',
     'rpc_decodescript.py',
     'rpc_blockchain.py',
diff --git a/test/functional/wallet_groups.py b/test/functional/wallet_groups.py
new file mode 100755
index 0000000000..0d27815da0
--- /dev/null
+++ b/test/functional/wallet_groups.py
@@ -0,0 +1,67 @@
+#!/usr/bin/env python3
+# Copyright (c) 2018 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 wallet group functionality."""
+
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import (
+    assert_equal,
+)
+
+def assert_approx(v, vexp, vspan=0.00001):
+    if v < vexp - vspan:
+        raise AssertionError("%s < [%s..%s]" % (str(v), str(vexp - vspan), str(vexp + vspan)))
+    if v > vexp + vspan:
+        raise AssertionError("%s > [%s..%s]" % (str(v), str(vexp - vspan), str(vexp + vspan)))
+
+class WalletGroupTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.setup_clean_chain = True
+        self.num_nodes = 3
+        self.extra_args = [[], [], ['-avoidpartialspends']]
+
+    def run_test (self):
+        # Mine some coins
+        self.nodes[0].generate(110)
+
+        # Get some addresses from the two nodes
+        addr1 = [self.nodes[1].getnewaddress() for i in range(3)]
+        addr2 = [self.nodes[2].getnewaddress() for i in range(3)]
+        addrs = addr1 + addr2
+
+        # Send 1 + 0.5 coin to each address
+        [self.nodes[0].sendtoaddress(addr, 1.0) for addr in addrs]
+        [self.nodes[0].sendtoaddress(addr, 0.5) for addr in addrs]
+
+        self.nodes[0].generate(1)
+        self.sync_all()
+
+        # For each node, send 0.2 coins back to 0;
+        # - node[1] should pick one 0.5 UTXO and leave the rest
+        # - node[2] should pick one (1.0 + 0.5) UTXO group corresponding to a
+        #   given address, and leave the rest
+        txid1 = self.nodes[1].sendtoaddress(self.nodes[0].getnewaddress(), 0.2)
+        tx1 = self.nodes[1].getrawtransaction(txid1, True)
+        # txid1 should have 1 input and 2 outputs
+        assert_equal(1, len(tx1["vin"]))
+        assert_equal(2, len(tx1["vout"]))
+        # one output should be 0.2, the other should be ~0.3
+        v = [vout["value"] for vout in tx1["vout"]]
+        v.sort()
+        assert_approx(v[0], 0.2)
+        assert_approx(v[1], 0.3, 0.0001)
+
+        txid2 = self.nodes[2].sendtoaddress(self.nodes[0].getnewaddress(), 0.2)
+        tx2 = self.nodes[2].getrawtransaction(txid2, True)
+        # txid2 should have 2 inputs and 2 outputs
+        assert_equal(2, len(tx2["vin"]))
+        assert_equal(2, len(tx2["vout"]))
+        # one output should be 0.2, the other should be ~1.3
+        v = [vout["value"] for vout in tx2["vout"]]
+        v.sort()
+        assert_approx(v[0], 0.2)
+        assert_approx(v[1], 1.3, 0.0001)
+
+if __name__ == '__main__':
+    WalletGroupTest().main ()