Function combinerawtransaction

src/rpc/rawtransaction.cpp:728–809

}

static RPCHelpMan combinerawtransaction()
{
    return RPCHelpMan{"combinerawtransaction",
                "\nCombine multiple partially signed transactions into one transaction.\n"
                "The combined transaction may be another partially signed transaction or a \n"
                "fully signed transaction.",
                {
                    {"txs", RPCArg::Type::ARR, RPCArg::Optional::NO, "The hex strings of partially signed transactions",
                        {
                            {"hexstring", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED, "A hex-encoded raw transaction"},
                        },
                        },
                },
                RPCResult{
                    RPCResult::Type::STR, "", "The hex-encoded raw transaction with signature(s)"
                },
                RPCExamples{
                    HelpExampleCli("combinerawtransaction", R"('["myhex1", "myhex2", "myhex3"]')")
                },
        [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{

    UniValue txs = request.params[0].get_array();
    std::vector<CMutableTransaction> txVariants(txs.size());

    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. Make sure the tx has at least one input.", idx));
        }
    }

    if (txVariants.empty()) {
        throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "Missing transactions");
    }

    // mergedTx will end up with all the signatures; it
    // starts as a clone of the rawtx:
    CMutableTransaction mergedTx(txVariants[0]);

    // Fetch previous transactions (inputs):
    CCoinsView viewDummy;
    CCoinsViewCache view(&viewDummy);
    {
        NodeContext& node = EnsureAnyNodeContext(request.context);
        const CTxMemPool& mempool = EnsureMemPool(node);
        ChainstateManager& chainman = EnsureChainman(node);
        LOCK2(cs_main, mempool.cs);
        CCoinsViewCache &viewChain = chainman.ActiveChainstate().CoinsTip();
        CCoinsViewMemPool viewMempool(&viewChain, mempool);
        view.SetBackend(viewMempool); // temporarily switch cache backend to db+mempool view

        for (const CTxIn& txin : mergedTx.vin) {
            view.AccessCoin(txin.prevout); // Load entries from viewChain into view; can fail.
        }

        view.SetBackend(viewDummy); // switch back to avoid locking mempool for too long
    }