Create a wallet as follows:

```sh
$ bitcoin-cli createwallet "watchonly" true
$ bitcoin-cli -rpcwallet=watchonly getwalletinfo
{
   ...
   "private_keys_enabled": false
}
```

The following should fail, but doesn't:

```sh
$ bitcoin-cli -rpcwallet=watchonly encryptwallet 1234
wallet encrypted; The keypool has been flushed and a new HD seed was generated (if you are using HD). You need to make a new backup.
```

It partially fails silently, because it doesn't actually add a seed. But it does ask for a password when calling `dumpwallet`, which doesn't make sense because we currently don't encrypt anything other than private keys.  
"                \"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"
            "    \"label\": \"label\",       (string) A comment for the address/transaction, if any\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 \n"
            "                                         'send' category of transactions.\n"
            "    \"confirmations\": n,       (numeric) The number of confirmations for the transaction. Negative confirmations indicate the\n"
            "                                         transaction conflicts with the block chain\n"
            "    \"trusted\": xxx,           (bool) Whether we consider the outputs of this unconfirmed transaction safe to spend.\n"
            "    \"blockhash\": \"hashvalue\", (string) The block hash containing the transaction.\n"
            "    \"blockindex\": n,          (numeric) The index of the transaction in the block that includes it.\n"
            "    \"blocktime\": xxx,         (numeric) The block time in seconds since epoch (1 Jan 1970 GMT).\n"
            "    \"txid\": \"transactionid\", (string) The transaction id.\n"
            "    \"time\": xxx,              (numeric) The transaction time in seconds since epoch (midnight Jan 1 1970 GMT).\n"
            "    \"timereceived\": xxx,      (numeric) The time received in seconds since epoch (midnight Jan 1 1970 GMT).\n"
            "    \"comment\": \"...\",       (string) If a comment is associated with the transaction.\n"
            "    \"bip125-replaceable\": \"yes|no|unknown\",  (string) Whether this transaction could be replaced due to BIP125 (replace-by-fee);\n"
            "                                                     may be unknown for unconfirmed transactions not in the mempool\n"
            "    \"abandoned\": xxx          (bool) 'true' if the transaction has been abandoned (inputs are respendable). Only available for the \n"
            "                                         'send' category of transactions.\n"
            "  }\n"
            "]\n"
                },
                RPCExamples{
            "\nList the most recent 10 transactions in the systems\n"
            + HelpExampleCli("listtransactions", "") +
            "\nList transactions 100 to 120\n"
            + HelpExampleCli("listtransactions", "\"*\" 20 100") +