Accumulate result UniValue in SignTransaction

SignTransaction will be called multiple times in the future. Pass
it a result UniValue so that it can accumulate the results of multiple
SignTransaction passes.

Author: achow101

src/rpc/rawtransaction.cpp

@@ -763,7 +763,9 @@ static UniValue signrawtransactionwithkey(const JSONRPCRequest& request)
     // Parse the prevtxs array
     ParsePrevouts(request.params[2], &keystore, coins);
 
-    return SignTransaction(mtx, &keystore, coins, request.params[3]);
+    UniValue result(UniValue::VOBJ);
+    SignTransaction(mtx, &keystore, coins, request.params[3], result);
+    return result;
 }
 
 static UniValue sendrawtransaction(const JSONRPCRequest& request)

src/rpc/rawtransaction_util.cpp

@@ -268,7 +268,7 @@ void ParsePrevouts(const UniValue& prevTxsUnival, FillableSigningProvider* keyst
     }
 }
 
-UniValue SignTransaction(CMutableTransaction& mtx, const SigningProvider* keystore, const std::map<COutPoint, Coin>& coins, const UniValue& hashType)
+void SignTransaction(CMutableTransaction& mtx, const SigningProvider* keystore, const std::map<COutPoint, Coin>& coins, const UniValue& hashType, UniValue& result)
 {
     int nHashType = ParseSighashString(hashType);
 
@@ -319,12 +319,12 @@ UniValue SignTransaction(CMutableTransaction& mtx, const SigningProvider* keysto
     }
     bool fComplete = vErrors.empty();
 
-    UniValue result(UniValue::VOBJ);
     result.pushKV("hex", EncodeHexTx(CTransaction(mtx)));
     result.pushKV("complete", fComplete);
     if (!vErrors.empty()) {
+        if (result.exists("errors")) {
+            vErrors.push_backV(result["errors"].getValues());
+        }
         result.pushKV("errors", vErrors);
     }
-
-    return result;
 }

src/rpc/rawtransaction_util.h

@@ -21,9 +21,9 @@ class SigningProvider;
  * @param  keystore      Temporary keystore containing signing keys
  * @param  coins         Map of unspent outputs
  * @param  hashType      The signature hash type
- * @returns JSON object with details of signed transaction
+ * @param result         JSON object where signed transaction results accumulate
  */
-UniValue SignTransaction(CMutableTransaction& mtx, const SigningProvider* keystore, const std::map<COutPoint, Coin>& coins, const UniValue& hashType);
+void SignTransaction(CMutableTransaction& mtx, const SigningProvider* keystore, const std::map<COutPoint, Coin>& coins, const UniValue& hashType, UniValue& result);
 
 /**
   * Parse a prevtxs UniValue array and get the map of coins from it

src/wallet/rpcwallet.cpp

@@ -3281,7 +3281,9 @@ UniValue signrawtransactionwithwallet(const JSONRPCRequest& request)
     // Parse the prevtxs array
     ParsePrevouts(request.params[1], nullptr, coins);
 
-    return SignTransaction(mtx, &*pwallet->GetLegacyScriptPubKeyMan(), coins, request.params[2]);
+    UniValue result(UniValue::VOBJ);
+    SignTransaction(mtx, &*pwallet->GetLegacyScriptPubKeyMan(), coins, request.params[2], result);
+    return result;
 }
 
 static UniValue bumpfee(const JSONRPCRequest& request)