rpc: Adjust witness-tx deserialize error message

src/rpc/mining.cpp

@@ -346,7 +346,7 @@ static UniValue generateblock(const JSONRPCRequest& request)
             txs.push_back(MakeTransactionRef(std::move(mtx)));
 
         } else {
-            throw JSONRPCError(RPC_DESERIALIZATION_ERROR, strprintf("Transaction decode failed for %s", str));
+            throw JSONRPCError(RPC_DESERIALIZATION_ERROR, strprintf("Transaction decode failed for %s. Make sure the tx has at least one input.", str));
         }
     }
 

src/rpc/rawtransaction.cpp

@@ -645,7 +645,7 @@ static UniValue combinerawtransaction(const JSONRPCRequest& request)
 
     for (unsigned int idx = 0; idx < txs.size(); idx++) {
         if (!DecodeHexTx(txVariants[idx], txs[idx].get_str())) {
-            throw JSONRPCError(RPC_DESERIALIZATION_ERROR, strprintf("TX decode failed for tx %d", idx));
+            throw JSONRPCError(RPC_DESERIALIZATION_ERROR, strprintf("TX decode failed for tx %d. Make sure the tx has at least one input.", idx));
         }
     }
 
@@ -767,7 +767,7 @@ static UniValue signrawtransactionwithkey(const JSONRPCRequest& request)
 
     CMutableTransaction mtx;
     if (!DecodeHexTx(mtx, request.params[0].get_str())) {
-        throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed");
+        throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed. Make sure the tx has at least one input.");
     }
 
     FillableSigningProvider keystore;
@@ -831,10 +831,10 @@ static UniValue sendrawtransaction(const JSONRPCRequest& request)
         UniValueType(), // VNUM or VSTR, checked inside AmountFromValue()
     });
 
-    // parse hex string from parameter
     CMutableTransaction mtx;
-    if (!DecodeHexTx(mtx, request.params[0].get_str()))
-        throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed");
+    if (!DecodeHexTx(mtx, request.params[0].get_str())) {
+        throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed. Make sure the tx has at least one input.");
+    }
     CTransactionRef tx(MakeTransactionRef(std::move(mtx)));
 
     const CFeeRate max_raw_tx_fee_rate = request.params[1].isNull() ?
@@ -905,7 +905,7 @@ static UniValue testmempoolaccept(const JSONRPCRequest& request)
 
     CMutableTransaction mtx;
     if (!DecodeHexTx(mtx, request.params[0].get_array()[0].get_str())) {
-        throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed");
+        throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed. Make sure the tx has at least one input.");
     }
     CTransactionRef tx(MakeTransactionRef(std::move(mtx)));
     const uint256& tx_hash = tx->GetHash();

src/wallet/rpcdump.cpp

@@ -334,8 +334,9 @@ UniValue importprunedfunds(const JSONRPCRequest& request)
     CWallet* const pwallet = wallet.get();
 
     CMutableTransaction tx;
-    if (!DecodeHexTx(tx, request.params[0].get_str()))
-        throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed");
+    if (!DecodeHexTx(tx, request.params[0].get_str())) {
+        throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed. Make sure the tx has at least one input.");
+    }
     uint256 hashTx = tx.GetHash();
 
     CDataStream ssMB(ParseHexV(request.params[1], "proof"), SER_NETWORK, PROTOCOL_VERSION);

src/wallet/rpcwallet.cpp

@@ -3230,7 +3230,7 @@ UniValue signrawtransactionwithwallet(const JSONRPCRequest& request)
 
     CMutableTransaction mtx;
     if (!DecodeHexTx(mtx, request.params[0].get_str())) {
-        throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed");
+        throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed. Make sure the tx has at least one input.");
     }
 
     // Sign the transaction