Following a discussion that I started firstly on the Bitcoin dev's mailing list, and then on StackExchange and Reddit, regarding some weird inconsistencies I noticed when I was working on a function to derive the p2sh from a multisig script, I'm here now to report what seems to be a bug in `addmultisigaddress` method.

Reference of the discussions:
https://bitcoin.stackexchange.com/questions/87579/multisig-scripts-hashing-p2sh-difference-between-legacy-and-segwit
https://www.reddit.com/r/Bitcoin/comments/bmiuk5/multisig_scripts_hashing_p2sh_difference_between/

## Example:

```bash
bitcoin-cli addmultisigaddress 1 '["045897fee25bd7c5692510b2f50fcae9aa20fbc4d49d59814f4c7fdb5c4bc6eb1c0ce382458f9588e922e0d509ed8d34856787380075b00418b02e0bf7c652ef9d","02ac46c6d74d15e60f4f1035ff07ef740aca1d68d55ba0b8d336a73d7a35858831","0224a4dc5620714a9ecf67a09583d1e4c04f5bedb8ecea99028da05bb15a2a7e07"]'
{
  "address": "36ULucjWUTrDvaJzCyhFoVbDoNS6Zum2Du",
  "redeemScript": "5141045897fee25bd7c5692510b2f50fcae9aa20fbc4d49d59814f4c7fdb5c4bc6eb1c0ce382458f9588e922e0d509ed8d34856787380075b00418b02e0bf7c652ef9d2102ac46c6d74d15e60f4f1035ff07ef740aca1d68d55ba0b8d336a73d7a35858831210224a4dc5620714a9ecf67a09583d1e4c04f5bedb8ecea99028da05bb15a2a7e0753ae"
}

bitcoin-cli createmultisig 1 '["045897fee25bd7c5692510b2f50fcae9aa20fbc4d49d59814f4c7fdb5c4bc6eb1c0ce382458f9588e922e0d509ed8d34856787380075b00418b02e0bf7c652ef9d","02ac46c6d74d15e60f4f1035ff07ef740aca1d68d55ba0b8d336a73d7a35858831","0224a4dc5620714a9ecf67a09583d1e4c04f5bedb8ecea99028da05bb15a2a7e07"]'
{
  "address": "3GiimyxF1R5VixfBFAbQZbuy9EesD2r6n1",
  "redeemScript": "5141045897fee25bd7c5692510b2f50fcae9aa20fbc4d49d59814f4c7fdb5c4bc6eb1c0ce382458f9588e922e0d509ed8d34856787380075b00418b02e0bf7c652ef9d2102ac46c6d74d15e60f4f1035ff07ef740aca1d68d55ba0b8d336a73d7a35858831210224a4dc5620714a9ecf67a09583d1e4c04f5bedb8ecea99028da05bb15a2a7e0753ae"
}
```

## Expected behaviour:

Both the two calls should return the same legacy address, because `addmultisigaddress` uses p2sh-segwit which is the default address type for the wallet, but segwit does not support uncompressed keys, so the first call should fallback to legacy.

## Actual behaviour:

The first call is returning an invalid segwit address.

@achow101 answered to my email to the dev list and also to my question on StackExchange and he believes that this is a bug and it could be related to the fact that the uncompressed pubkey is not part of my wallet.

---

Another interesting thing is that, as user @ugamkamat pointed out on StackExchange, changing the position of the uncompressed public key from the first to the last, the first call returns a legacy address:

```bash
./bitcoin-cli addmultisigaddress 1 '["02ac46c6d74d15e60f4f1035ff07ef740aca1d68d55ba0b8d336a73d7a35858831","0224a4dc5620714a9ecf67a09583d1e4c04f5bedb8ecea99028da05bb15a2a7e07","045897fee25bd7c5692510b2f50fcae9aa20fbc4d49d59814f4c7fdb5c4bc6eb1c0ce382458f9588e922e0d509ed8d34856787380075b00418b02e0bf7c652ef9d"]'
{
  "address": "35RZ8AHKWGGbNcRDaCUtznSVnPRWGqVPJu",
  "redeemScript": "512102ac46c6d74d15e60f4f1035ff07ef740aca1d68d55ba0b8d336a73d7a35858831210224a4dc5620714a9ecf67a09583d1e4c04f5bedb8ecea99028da05bb15a2a7e0741045897fee25bd7c5692510b2f50fcae9aa20fbc4d49d59814f4c7fdb5c4bc6eb1c0ce382458f9588e922e0d509ed8d34856787380075b00418b02e0bf7c652ef9d53ae"
}
```

I'd really like to try to contribute to the project, so I'm trying to figure out where the problem could be in the code. Any suggestion is welcome.
if (request.fHelp || request.params.size() > 4)
        throw std::runtime_error(
            RPCHelpMan{"listsinceblock",
                "\nGet all transactions in blocks since block [blockhash], or all transactions if omitted.\n"
                "If \"blockhash\" is no longer a part of the main chain, transactions from the fork point onward are included.\n"
                "Additionally, if include_removed is set, transactions affecting the wallet which were removed are returned in the \"removed\" array.\n",
                {
                    {"blockhash", RPCArg::Type::STR, RPCArg::Optional::OMITTED_NAMED_ARG, "If set, the block hash to list transactions since, otherwise list all transactions."},
                    {"target_confirmations", RPCArg::Type::NUM,  "1", "Return the nth block hash from the main chain. e.g. 1 would mean the best block hash. Note: this is not used as a filter, but only affects [lastblock] in the return value"},
                    {"include_watchonly", RPCArg::Type::BOOL,  "false", "Include transactions to watch-only addresses (see 'importaddress')"},
                    {"include_removed", RPCArg::Type::BOOL,  "true", "Show transactions that were removed due to a reorg in the \"removed\" array\n"
            "                                                           (not guaranteed to work on pruned nodes)"},
                },
                RPCResult{
            "{\n"
            "  \"transactions\": [\n"
            "    \"address\":\"address\",    (string) The bitcoin address of the transaction.\n"
            "    \"category\":               (string) The transaction category.\n"
            "                \"send\"                  Transactions sent.\n"
            "                \"receive\"               Non-coinbase transactions received.\n"
            "                \"generate\"              Coinbase transactions received with more than 100 confirmations.\n"
            "                \"immature\"              Coinbase transactions received with 100 or fewer confirmations.\n"
            "                \"orphan\"                Orphaned coinbase transactions received.\n"
            "    \"amount\": x.xxx,          (numeric) The amount in " + CURRENCY_UNIT + ". This is negative for the 'send' category, and is positive\n"
            "                                         for all other categories\n"
            "    \"vout\" : n,               (numeric) the vout value\n"
            "    \"fee\": x.xxx,             (numeric) The amount of the fee in " + CURRENCY_UNIT + ". This is negative and only available for the 'send' category of transactions.\n"
            "    \"confirmations\": n,       (numeric) The number of confirmations for the transaction.\n"
            "                                          When it's < 0, it means the transaction conflicted that many blocks ago.\n"
            "    \"blockhash\": \"hashvalue\",     (string) The block hash containing the transaction.\n"