Merge #16239: wallet/rpc: follow-up clean-up/fixes to avoid_reuse

71d0344cf25d3aaf60112c5248198c444bc98105 docs: release note wording (Karl-Johan Alm)
3d2ff379131a01e4e9f9648b150e806104a23795 wallet/rpc: use static help text (Karl-Johan Alm)
53c3c1ea9e20f881c843a9219e48cec202e962f8 wallet/rpc/getbalances: add entry for 'mine.used' balance in results (Karl-Johan Alm)

Pull request description:

  This addresses a few remaining issues pointed out in #13756:

  * First commit addresses https://github.com/bitcoin/bitcoin/pull/13756#discussion_r284907468
  * Second commit addresses https://github.com/bitcoin/bitcoin/pull/13756#discussion_r294868973

  Ping jnewbery and achow101 as they pointed out these issues.

ACKs for commit 71d034:
  jnewbery:
    ACK 71d0344cf25d3aaf60112c5248198c444bc98105
  meshcollider:
    re-utACK https://github.com/bitcoin/bitcoin/pull/16239/commits/71d0344cf25d3aaf60112c5248198c444bc98105

Tree-SHA512: 5e28822af0574ad07dbbed21aa2fe7866bf5770b4c0a1c150ad0da8af3152bcfb7170330a7497fa500326c594740ecf63733cf58325821e2811d7b911d5783a0

1 files changed, 19 insertions, 11 deletions

diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 3232c65bca..eae5f876ea 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -383,7 +383,7 @@ static UniValue sendtoaddress(const JSONRPCRequest& request)
             "       \"UNSET\"\n"
             "       \"ECONOMICAL\"\n"
             "       \"CONSERVATIVE\""},
-                    {"avoid_reuse", RPCArg::Type::BOOL, /* default */ pwallet->IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE) ? "true" : "unavailable", "Avoid spending from dirty addresses; addresses are considered\n"
+                    {"avoid_reuse", RPCArg::Type::BOOL, /* default */ "true", "(only available if avoid_reuse wallet flag is set) Avoid spending from dirty addresses; addresses are considered\n"
             "                             dirty if they have previously been used in a transaction."},
                 },
                 RPCResult{
@@ -743,7 +743,7 @@ static UniValue getbalance(const JSONRPCRequest& request)
                     {"dummy", RPCArg::Type::STR, RPCArg::Optional::OMITTED_NAMED_ARG, "Remains for backward compatibility. Must be excluded or set to \"*\"."},
                     {"minconf", RPCArg::Type::NUM, /* default */ "0", "Only include transactions confirmed at least this many times."},
                     {"include_watchonly", RPCArg::Type::BOOL, /* default */ "false", "Also include balance in watch-only addresses (see 'importaddress')"},
-                    {"avoid_reuse", RPCArg::Type::BOOL, /* default */ pwallet->IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE) ? "true" : "unavailable", "Do not include balance in dirty outputs; addresses are considered dirty if they have previously been used in a transaction."},
+                    {"avoid_reuse", RPCArg::Type::BOOL, /* default */ "true", "(only available if avoid_reuse wallet flag is set) Do not include balance in dirty outputs; addresses are considered dirty if they have previously been used in a transaction."},
                 },
                 RPCResult{
             "amount              (numeric) The total amount in " + CURRENCY_UNIT + " received for this wallet.\n"
@@ -2409,6 +2409,7 @@ static UniValue getbalances(const JSONRPCRequest& request)
             "      \"trusted\": xxx                 (numeric) trusted balance (outputs created by the wallet or confirmed outputs)\n"
             "      \"untrusted_pending\": xxx       (numeric) untrusted pending balance (outputs created by others that are in the 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"
             "      \"trusted\": xxx                 (numeric) trusted balance (outputs created by the wallet or confirmed outputs)\n"
@@ -2441,6 +2442,12 @@ static UniValue getbalances(const JSONRPCRequest& request)
         balances_mine.pushKV("trusted", ValueFromAmount(bal.m_mine_trusted));
         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()) {
@@ -2885,11 +2892,8 @@ static UniValue listunspent(const JSONRPCRequest& request)
         return NullUniValue;
     }
 
-    bool avoid_reuse = pwallet->IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE);
-
-    if (request.fHelp || request.params.size() > 5)
-        throw std::runtime_error(
-            RPCHelpMan{"listunspent",
+    const RPCHelpMan help{
+                "listunspent",
                 "\nReturns array of unspent transaction outputs\n"
                 "with between minconf and maxconf (inclusive) confirmations.\n"
                 "Optionally filter to only include txouts paid to specified addresses.\n",
@@ -2926,9 +2930,7 @@ static UniValue listunspent(const JSONRPCRequest& request)
             "    \"witnessScript\" : \"script\" (string) witnessScript if the scriptPubKey is P2WSH or P2SH-P2WSH\n"
             "    \"spendable\" : xxx,        (bool) Whether we have the private keys to spend this output\n"
             "    \"solvable\" : xxx,         (bool) Whether we know how to spend this output, ignoring the lack of keys\n"
-            + (avoid_reuse ?
-            "    \"reused\" : xxx,           (bool) Whether this output is reused/dirty (sent to an address that was previously spent from)\n" :
-            "") +
+            "    \"reused\" : xxx,           (bool) (only present if avoid_reuse is set) Whether this output is reused/dirty (sent to an address that was previously spent from)\n"
             "    \"desc\" : xxx,             (string, only when solvable) A descriptor for spending this output\n"
             "    \"safe\" : xxx              (bool) Whether this output is considered safe to spend. Unconfirmed transactions\n"
             "                              from outside keys and unconfirmed replacement transactions are considered unsafe\n"
@@ -2944,7 +2946,11 @@ static UniValue listunspent(const JSONRPCRequest& request)
             + HelpExampleCli("listunspent", "6 9999999 '[]' true '{ \"minimumAmount\": 0.005 }'")
             + HelpExampleRpc("listunspent", "6, 9999999, [] , true, { \"minimumAmount\": 0.005 } ")
                 },
-            }.ToString());
+            };
+
+    if (request.fHelp || !help.IsValidNumArgs(request.params.size())) {
+        throw std::runtime_error(help.ToString());
+    }
 
     int nMinDepth = 1;
     if (!request.params[0].isNull()) {
@@ -3017,6 +3023,8 @@ static UniValue listunspent(const JSONRPCRequest& request)
 
     LOCK(pwallet->cs_wallet);
 
+    const bool avoid_reuse = pwallet->IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE);
+
     for (const COutput& out : vecOutputs) {
         CTxDestination address;
         const CScript& scriptPubKey = out.tx->tx->vout[out.i].scriptPubKey;