Merge #904: Fix parsing of amount commitments from prevtxs in signrawtrasnactionwithkey

a4045d2 Fix parsing of amount commitments from prevtxs in signrawtransactionwithkey (Glenn Willen)

Pull request description:

Tree-SHA512: 4bc38ac4bcf09c3dc0dd5a5bdcb75a031a6a86a8848390e63c1c466f1788155f6f6456b1aa3b36078c35d62d6093667c70a6895eb1ab59d6704300ebac8bbe56

Author: stevenroose

src/rpc/rawtransaction.cpp

@@ -1105,8 +1105,7 @@ UniValue SignTransaction(interfaces::Chain& chain, CMutableTransaction& mtx, con
                     newcoin.out.nValue = CConfidentialValue(AmountFromValue(find_value(prevOut, "amount")));
                 } else if (prevOut.exists("amountcommitment")) {
                     // Segwit sigs require the amount commitment to be sighashed
-                    uint256 asset_commit = uint256S(prevOut["amountcommitment"].get_str());
-                    newcoin.out.nValue.vchCommitment = std::vector<unsigned char>(asset_commit.begin(), asset_commit.end());
+                    newcoin.out.nValue.vchCommitment = ParseHexO(prevOut, "amountcommitment");
                 }
                 newcoin.nHeight = 1;
                 view.AddCoin(out, std::move(newcoin), true);