DEFAULT function not working with status column

[luisfmcalado]

Overview of the Issue

It fails when inserting records with the DEFAULT function receiving the column name status.

Reproduction Steps

Steps to reproduce this issue:

1. Deploy the following vschema:

{
  "sharded": true,
  "vindexes": {
    "unicode_loose_md5": {
      "type": "unicode_loose_md5"
    }
  },
  "tables": {
    "user": {
      "column_vindexes": [
        {
          "column": "username",
          "name": "unicode_loose_md5"
        }
      ]
    }
  }
}

1. Deploy the following schema:

CREATE TABLE `user` (
  username varchar(128) NOT NULL,
  `status` varchar(128) NOT NULL DEFAULT "UNKNOWN"
);

1. Run INSERT INTO user(username, status) VALUES ("Chuck", DEFAULT(`status`))
2. It shows the following error:

ERROR 1105 (HY000) at line 1: vtgate: http://vtgate-865353cb-55c58f5bbf-6l6b7:15000/: execInsertSharded: target: live.80-.master, used tablet: zone1-3423003548 (172.31.29.20): vttablet: rpc error: code = InvalidArgument desc = syntax error at position 73 near 'status' (CallerID: user1)

Operating system and Environment details

Using vitess operator with Kubernetes version 1.15
MariaDB 10.3.22
Running with:

vtctld: vitess/lite:v6.0.20-20200429
vtgate: vitess/lite:v6.0.20-20200429
vttablet: vitess/lite:v6.0.20-20200429
vtbackup: vitess/lite:v6.0.20-20200429

Log Fragments

I didn't see any log related to the error.