[backport#16239] wallet/rpc/getbalances: add entry for 'mine.used' ba…

…lance in results

Summary:
bitcoin/bitcoin@53c3c1e

---

Partial backport of Core [[bitcoin/bitcoin#16239 | PR16239]]

Test Plan:
  ninja
  ./src/bitcoind -regtest -daemon
  ./src/bitcoin-cli -regtest getbalances help

check that it looks right

  test_runner.py wallet_avoidreuse

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D6482

src/wallet/rpcwallet.cpp

@@ -2931,6 +2931,9 @@ static UniValue getbalances(const Config &config,
             "mempool)\n"
             "      \"immature\": xxx                (numeric) balance from "
             "immature coinbase outputs\n"
+            "      \"used\": xxx                    (numeric) (only present if "
+            "avoid_reuse is set) balance from coins sent to addresses that "
+            "were previously spent from (potentially privacy violating)\n"
             "    },\n"
             "    \"watchonly\": {                   (object) watchonly "
             "balances (not present if wallet does not watch anything)\n"
@@ -2968,6 +2971,17 @@ static UniValue getbalances(const Config &config,
         balances_mine.pushKV("untrusted_pending",
                              ValueFromAmount(bal.m_mine_untrusted_pending));
         balances_mine.pushKV("immature", ValueFromAmount(bal.m_mine_immature));
+        if (wallet.IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE)) {
+            // If the AVOID_REUSE flag is set, bal has been set to just the
+            // un-reused address balance. Get the total balance, and then
+            // subtract bal to get the reused address balance.
+            const auto full_bal = wallet.GetBalance(0, false);
+            balances_mine.pushKV(
+                "used", ValueFromAmount(full_bal.m_mine_trusted +
+                                        full_bal.m_mine_untrusted_pending -
+                                        bal.m_mine_trusted -
+                                        bal.m_mine_untrusted_pending));
+        }
         balances.pushKV("mine", balances_mine);
     }
     if (wallet.HaveWatchOnly()) {

test/functional/wallet_avoidreuse.py

@@ -16,9 +16,11 @@
 
 def assert_approx(v, vexp, vspan=0.00001):
     if v < vexp - vspan:
-        raise AssertionError("{} < [{}..{}]".format(str(v), str(vexp - vspan), str(vexp + vspan)))
+        raise AssertionError("{} < [{}..{}]".format(
+            str(v), str(vexp - vspan), str(vexp + vspan)))
     if v > vexp + vspan:
-        raise AssertionError("{} > [{}..{}]".format(str(v), str(vexp - vspan), str(vexp + vspan)))
+        raise AssertionError("{} > [{}..{}]".format(
+            str(v), str(vexp - vspan), str(vexp + vspan)))
 
 
 def reset_balance(node, discardaddr):
@@ -74,6 +76,13 @@ def assert_unspent(node, total_count=None, total_sum=None,
         assert_approx(stats["reused"]["sum"], reused_sum, 0.001)
 
 
+def assert_balances(node, mine):
+    '''Make assertions about a node's getbalances output'''
+    got = node.getbalances()["mine"]
+    for k, v in mine.items():
+        assert_approx(got[k], v, 0.001)
+
+
 class AvoidReuseTest(BitcoinTestFramework):
 
     def set_test_params(self):
@@ -171,6 +180,11 @@ def test_fund_send_fund_senddirty(self):
             total_sum=10,
             reused_supported=True,
             reused_count=0)
+        # getbalances should show no used, 10 BCH trusted
+        assert_balances(self.nodes[1], mine={"used": 0, "trusted": 10})
+        # node 0 should not show a used entry, as it does not enable
+        # avoid_reuse
+        assert("used" not in self.nodes[0].getbalances()["mine"])
 
         self.nodes[1].sendtoaddress(retaddr, 5)
         self.nodes[0].generate(1)
@@ -183,6 +197,8 @@ def test_fund_send_fund_senddirty(self):
             total_sum=5,
             reused_supported=True,
             reused_count=0)
+        # getbalances should show no used, 5 BCH trusted
+        assert_balances(self.nodes[1], mine={"used": 0, "trusted": 5})
 
         self.nodes[0].sendtoaddress(fundaddr, 10)
         self.nodes[0].generate(1)
@@ -196,6 +212,8 @@ def test_fund_send_fund_senddirty(self):
             total_sum=15,
             reused_count=1,
             reused_sum=10)
+        # getbalances should show 10 used, 5 BCH trusted
+        assert_balances(self.nodes[1], mine={"used": 10, "trusted": 5})
 
         self.nodes[1].sendtoaddress(
             address=retaddr, amount=10, avoid_reuse=False)
@@ -206,6 +224,8 @@ def test_fund_send_fund_senddirty(self):
             total_count=1,
             total_sum=5,
             reused_count=0)
+        # getbalances should show no used, 5 BCH trusted
+        assert_balances(self.nodes[1], mine={"used": 0, "trusted": 5})
 
         # node 1 should now have about 5 BCH left (for both cases)
         assert_approx(self.nodes[1].getbalance(), 5, 0.001)
@@ -235,6 +255,8 @@ def test_fund_send_fund_send(self):
             total_sum=10,
             reused_supported=True,
             reused_count=0)
+        # getbalances should show no used, 10 BCH trusted
+        assert_balances(self.nodes[1], mine={"used": 0, "trusted": 10})
 
         self.nodes[1].sendtoaddress(retaddr, 5)
         self.nodes[0].generate(1)
@@ -247,6 +269,8 @@ def test_fund_send_fund_send(self):
             total_sum=5,
             reused_supported=True,
             reused_count=0)
+        # getbalances should show no used, 5 BCH trusted
+        assert_balances(self.nodes[1], mine={"used": 0, "trusted": 5})
 
         self.nodes[0].sendtoaddress(fundaddr, 10)
         self.nodes[0].generate(1)
@@ -260,6 +284,8 @@ def test_fund_send_fund_send(self):
             total_sum=15,
             reused_count=1,
             reused_sum=10)
+        # getbalances should show 10 used, 5 BCH trusted
+        assert_balances(self.nodes[1], mine={"used": 10, "trusted": 5})
 
         # node 1 should now have a balance of 5 (no dirty) or 15 (including
         # dirty)
@@ -279,6 +305,8 @@ def test_fund_send_fund_send(self):
             total_sum=11,
             reused_count=1,
             reused_sum=10)
+        # getbalances should show 10 used, 1 BCH trusted
+        assert_balances(self.nodes[1], mine={"used": 10, "trusted": 1})
 
         # node 1 should now have about 1 BCH left (no dirty) and 11 (including
         # dirty)