UInt160 type method in smart contract can return String, can be compiled, but can't be executed.

[superboyiii]

We need support this kind of return in compiler or ban it within exception. Compiler and ApplicationEngine are now in different behavior.

    public partial class Test : SmartContract
    {
        public static BigInteger Decimal()
        {
            return (BigInteger)Contract.Call(GetStateContractHash(), "decimals", CallFlags.ReadOnly);
        }

        public static UInt160 GetStateContractHash()
        {
            return "0xd2a4cff31913016155e38e474a2c06d08be276cf";
        }

    }

Compiler build it successfully:

In invokefunction:
Request:

{
  "jsonrpc": "2.0",
  "method": "invokefunction",
  "params": [
    "0x2b6692bc37b1837fd9ff6b4a9496fed6423dd492",
    "decimal",
    [],
    [
      {
        "account": "NdUL5oDPD159KeFpD5A9zw5xNF1xLX6nLT",
        "scopes": "Global"
      }
    ]
  ],
  "id": 3
}

Response:

{
    "jsonrpc": "2.0",
    "id": 3,
    "result": {
        "script": "wh8MB2RlY2ltYWwMFJLUPULW/paUSmv/2X+DsTe8kmYrQWJ9W1I=",
        "state": "FAULT",
        "gasconsumed": "1983480",
        "exception": "Invalid UInt160 length: expected 20 bytes, but got 42 bytes. UInt160 values must be exactly 20 bytes long.",
        "notifications": [],
        "stack": []
    }
}