"cleos sign transaction" broken in develop.

[taokayan]

due the returned transaction JSON string was changed in develop as compared to v2.0.4, "cleos sign" no longer work with the new transation JSON in which the action data is also jsonified:

for example: use ./cleos transfer eosio inita "0.0001 SYS" -s -d -j > trx1 to generate a unsigned transaction in JSON format.

in v2.0.4:

  "expiration": "2020-04-06T06:57:09",
  "ref_block_num": 1660,
  "ref_block_prefix": 1646371250,
  "max_net_usage_words": 0,
  "max_cpu_usage_ms": 0,
  "delay_sec": 0,
  "context_free_actions": [],
  "actions": [{
      "account": "eosio.token",
      "name": "transfer",
      "authorization": [{
          "actor": "eosio",
          "permission": "active"
        }
      ],
      "data": "0000000000ea3055000000000093dd740100000000000000045359530000000000"
    }
  ],
  "transaction_extensions": [],
  "signatures": [],
  "context_free_data": []
}

in develop:

  "expiration": "2020-04-06T07:02:47",
  "ref_block_num": 2335,
  "ref_block_prefix": 232832416,
  "max_net_usage_words": 0,
  "max_cpu_usage_ms": 0,
  "delay_sec": 0,
  "context_free_actions": [],
  "actions": [{
      "account": "eosio.token",
      "name": "transfer",
      "authorization": [{
          "actor": "eosio",
          "permission": "active"
        }
      ],
      "data": {
        "from": "eosio",
        "to": "inita",
        "quantity": "0.0001 SYS",
        "memo": ""
      },
      "hex_data": "0000000000ea3055000000000093dd740100000000000000045359530000000000"
    }
  ],
  "transaction_extensions": [],
  "signatures": [],
  "context_free_data": []
}

Trying to sign the transaction in cleos (./cleos sign -k PRIVATE_KEY trx1 -p) will result in error:

Error 3010006: Invalid transaction
Ensure that your transaction JSON follows the right transaction format!
Error Details:
Invalid transaction format: '{"expiration":"2020-04-06T06:56:58","ref_block_num":1638,"ref_block_prefix":2096313275,"max_net_usage_words":0,"max_cpu_usage_ms":0,"delay_sec":0,"context_free_actions":[],"actions":[{"account":"eosio.token","name":"transfer","authorization":[{"actor":"eosio","permission":"active"}],"data":{"from":"eosio","to":"inita","quantity":"0.0001 SYS","memo":""},"hex_data":"0000000000ea3055000000000093dd740100000000000000045359530000000000"}],"transaction_extensions":[],"signatures":[],"context_free_data":[]}'
Invalid cast from type 'object_type' to string

[heifner]

Resolved by #8931