Repository: dogecoin/dogecoin
File: src/rpc/mining.cpp (C++)

Code before:
        throw runtime_error(
            "submitblock \"hexdata\" ( \"jsonparametersobject\" )\n"
            "\nAttempts to submit new block to network.\n"
            "The 'jsonparametersobject' parameter is currently ignored.\n"
            "See https://en.bitcoin.it/wiki/BIP_0022 for full specification.\n"

            "\nArguments\n"
            "1. \"hexdata\"        (string, required) the hex-encoded block data to submit\n"
            "2. \"parameters\"     (string, optional) object of optional parameters\n"
            "    {\n"
            "      \"workid\" : \"id\"    (string, optional) if the server provided a workid, it MUST be included with submissions\n"
            "    }\n"
            "\nResult:\n"
            "\nExamples:\n"
            + HelpExampleCli("submitblock", "\"mydata\"")
            + HelpExampleRpc("submitblock", "\"mydata\"")
        );

    std::shared_ptr<CBlock> blockptr = std::make_shared<CBlock>();
    CBlock& block = *blockptr;
    if (!DecodeHexBlk(block, request.params[0].get_str()))
        throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "Block decode failed");

    if (block.vtx.empty() || !block.vtx[0]->IsCoinBase()) {
        throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "Block does not start with a coinbase");
    }

    uint256 hash = block.GetHash();
    bool fBlockPresent = false;
    {
        LOCK(cs_main);
        BlockMap::iterator mi = mapBlockIndex.find(hash);
        if (mi != mapBlockIndex.end()) {
            CBlockIndex *pindex = mi->second;
            if (pindex->IsValid(BLOCK_VALID_SCRIPTS))
                return "duplicate";
            if (pindex->nStatus & BLOCK_FAILED_MASK)
                return "duplicate-invalid";
            // Otherwise, we might only have the header - process the block before returning
            fBlockPresent = true;
        }
    }

    {
        LOCK(cs_main);
        BlockMap::iterator mi = mapBlockIndex.find(block.hashPrevBlock);
        if (mi != mapBlockIndex.end()) {
            int nHeight = chainActive.Height() + 1;
            UpdateUncommittedBlockStructures(block, mi->second, Params().GetConsensus(nHeight));
        }
    }

Review comment (suggestion):
I would change a bit the phrasing to emphasis that there is no transactions at all and that a valid block **has** to have at least one.

Something like this ?
"Block does not contain any transaction. Coinbase transaction required."

Code after:
        throw runtime_error(
            "submitblock \"hexdata\" ( \"jsonparametersobject\" )\n"
            "\nAttempts to submit new block to network.\n"
            "The 'jsonparametersobject' parameter is currently ignored.\n"
            "See https://en.bitcoin.it/wiki/BIP_0022 for full specification.\n"

            "\nArguments\n"
            "1. \"hexdata\"        (string, required) the hex-encoded block data to submit\n"
            "2. \"parameters\"     (string, optional) object of optional parameters\n"
            "    {\n"
            "      \"workid\" : \"id\"    (string, optional) if the server provided a workid, it MUST be included with submissions\n"
            "    }\n"
            "\nResult:\n"
            "\nExamples:\n"
            + HelpExampleCli("submitblock", "\"mydata\"")
            + HelpExampleRpc("submitblock", "\"mydata\"")
        );

    std::shared_ptr<CBlock> blockptr = std::make_shared<CBlock>();
    CBlock& block = *blockptr;
    if (!DecodeHexBlk(block, request.params[0].get_str()))
        throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "Block decode failed");

    if (block.vtx.empty())
    {
        throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "Block does not contain a coinbase transaction");
    } 

    if (!block.vtx[0]->IsCoinBase())
    {
        throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "Block does not start with a valid coinbase transaction");
    }

    uint256 hash = block.GetHash();
    bool fBlockPresent = false;
    {
        LOCK(cs_main);
        BlockMap::iterator mi = mapBlockIndex.find(hash);
        if (mi != mapBlockIndex.end()) {
            CBlockIndex *pindex = mi->second;
            if (pindex->IsValid(BLOCK_VALID_SCRIPTS))
                return "duplicate";
            if (pindex->nStatus & BLOCK_FAILED_MASK)
                return "duplicate-invalid";
            // Otherwise, we might only have the header - process the block before returning
            fBlockPresent = true;
        }
    }

    {
        LOCK(cs_main);