gettransaction: add an argument to decode the transaction

This adds a new boolean parameter 'decode' to the gettransaction call, which, if set to true, add a 'decoded' field to the result containing the decoded transaction

src/rpc/client.cpp

@@ -85,6 +85,7 @@ static const CRPCConvertParam vRPCConvertParams[] =
     { "getblockheader", 1, "verbose" },
     { "getchaintxstats", 0, "nblocks" },
     { "gettransaction", 1, "include_watchonly" },
+    { "gettransaction", 2, "decode" },
     { "getrawtransaction", 1, "verbose" },
     { "createrawtransaction", 0, "inputs" },
     { "createrawtransaction", 1, "outputs" },

src/wallet/rpcwallet.cpp

@@ -1649,6 +1649,7 @@ static UniValue gettransaction(const JSONRPCRequest& request)
                 {
                     {"txid", RPCArg::Type::STR, RPCArg::Optional::NO, "The transaction id"},
                     {"include_watchonly", RPCArg::Type::BOOL, /* default */ "true for watch-only wallets, otherwise false", "Whether to include watch-only addresses in balance calculation and details[]"},
+                    {"decode", RPCArg::Type::BOOL, /* default */ "false", "Whether to add a field with the decoded transaction"},
                 },
                 RPCResult{
             "{\n"
@@ -1684,11 +1685,13 @@ static UniValue gettransaction(const JSONRPCRequest& request)
             "    ,...\n"
             "  ],\n"
             "  \"hex\" : \"data\"         (string) Raw data for transaction\n"
+            "  \"decoded\" : transaction         (json object) Optional, the decoded transaction\n"
             "}\n"
                 },
                 RPCExamples{
                     HelpExampleCli("gettransaction", "\"1075db55d416d3ca199f55b6084e2115b9345e16c5cf302fc80e9d5fbf5d48d\"")
             + HelpExampleCli("gettransaction", "\"1075db55d416d3ca199f55b6084e2115b9345e16c5cf302fc80e9d5fbf5d48d\" true")
+            + HelpExampleCli("gettransaction", "\"1075db55d416d3ca199f55b6084e2115b9345e16c5cf302fc80e9d5fbf5d48d\" false true")
             + HelpExampleRpc("gettransaction", "\"1075db55d416d3ca199f55b6084e2115b9345e16c5cf302fc80e9d5fbf5d48d\"")
                 },
             }.Check(request);
@@ -1708,6 +1711,8 @@ static UniValue gettransaction(const JSONRPCRequest& request)
         filter |= ISMINE_WATCH_ONLY;
     }
 
+    bool decode_tx = request.params[2].isNull() ? false : request.params[2].get_bool();
+
     UniValue entry(UniValue::VOBJ);
     auto it = pwallet->mapWallet.find(hash);
     if (it == pwallet->mapWallet.end()) {
@@ -1733,6 +1738,12 @@ static UniValue gettransaction(const JSONRPCRequest& request)
     std::string strHex = EncodeHexTx(*wtx.tx, pwallet->chain().rpcSerializationFlags());
     entry.pushKV("hex", strHex);
 
+    if (decode_tx) {
+        UniValue decoded(UniValue::VOBJ);
+        TxToUniv(*wtx.tx, uint256(), decoded, false);
+        entry.pushKV("decoded", decoded);
+    }
+
     return entry;
 }
 
@@ -4175,7 +4186,7 @@ static const CRPCCommand commands[] =
     { "wallet",             "getrawchangeaddress",              &getrawchangeaddress,           {"address_type"} },
     { "wallet",             "getreceivedbyaddress",             &getreceivedbyaddress,          {"address","minconf"} },
     { "wallet",             "getreceivedbylabel",               &getreceivedbylabel,            {"label","minconf"} },
-    { "wallet",             "gettransaction",                   &gettransaction,                {"txid","include_watchonly"} },
+    { "wallet",             "gettransaction",                   &gettransaction,                {"txid","include_watchonly","decode"} },
     { "wallet",             "getunconfirmedbalance",            &getunconfirmedbalance,         {} },
     { "wallet",             "getbalances",                      &getbalances,                   {} },
     { "wallet",             "getwalletinfo",                    &getwalletinfo,                 {} },