Easy to reproduce:
### 20.3.13
```
SELECT 1
FORMAT JSON

{
        "meta":
        [
                {
                        "name": "1",
                        "type": "UInt8"
                }
        ],

        "data":
        [
                {
                        "1": 1
                }
        ],

        "rows": 1,

        "statistics":
        {
                "elapsed": 0.000203731,
                "rows_read": 1,
                "bytes_read": 1
        }
}
```

### 20.4.5
```
:) select 1 format JSON

SELECT 1
FORMAT JSON

{
        "meta":
        [
                {
                        "name": "1",
                        "type": "UInt8"
                }
        ],

        "data":
        [
                {
                        "1": 1
>>>>>>>> no closing bracket <<<<<<<<<<
        ],

        "rows": 1,

        "statistics":
        {
                "elapsed": 0.000771732,
                "rows_read": 1,
                "bytes_read": 1
        }
}
```
### master
```

SELECT 1
FORMAT JSON

{
        "meta":
        [
                {
                        "name": "1",
                        "type": "UInt8"
                }
        ],

        "data":
        [
                {
                        "1": 1
>>>>>>>> no closing bracket <<<<<<<<<<
        ],

        "rows": 1,

        "statistics":
        {
                "elapsed": 0.00103364,
                "rows_read": 1,
                "bytes_read": 1
        }
}

```

#pragma GCC optimize("-fno-var-tracking-assignments")
#endif
#define CLEAR_TO_END_OF_LINE "\033[K"
namespace DB
{
namespace ErrorCodes
{
    extern const int NETWORK_ERROR
    extern const int NO_DATA_TO_INSERT
    extern const int BAD_ARGUMENTS
    extern const int UNKNOWN_PACKET_FROM_SERVER
    extern const int UNEXPECTED_PACKET_FROM_SERVER
    extern const int CLIENT_OUTPUT_FORMAT_SPECIFIED
    extern const int INVALID_USAGE_OF_INPUT
    extern const int DEADLOCK_AVOIDED
    extern const int UNRECOGNIZED_ARGUMENTS
class Client : public Poco::Util::Applition
{
public:
    Client() = default
private:
    using StringSet = std::unordered_set<String>
    StringSet exit_strings
    {
        "exit", "quit", "logout",
        "учше", "йгше", "дщпщге",
        "exit", "quit", "logout",
        "учшеж", "йгшеж", "дщпщгеж",
        "q", "й", "\\q", "\\Q", "\\й", "\\Й", ":q", "Жй"