[BUG]: RBAC on update with input arrays causes error

[rderbier]

What version of Dgraph are you using?

v23 or v24.0.1

What is the hardware spec (RAM, CPU, OS)?

Cloud

What steps will reproduce the bug?

Deploy schema

type User @auth(
  
      update: { 
        rule: "{ $role: { eq: \"ADMIN\" } }" 
      }
  
){
  email: String! @id
  note: String
}

# Dgraph.Authorization {"VerificationKey":"6ABBAA2014CFF00289D20D20DA296F67","header":"X-Dgraph-AuthToken","namespace":"https://dgraph.io/jwt/claims","Algo":"HS256","ClosedByDefault":true}

from Postman send GraphQL request

mutation MyMutation($input: [AddUserInput!]!, $upsert: Boolean) {
  addUser(input: $input, upsert: $upsert) {
    numUids
    user {
      email
    }
  }
}

with variables

{   "upsert": true,
    "input" : [
        {"email": "a@hypermode.com"},
        {"email": "b@hypermode.com"},
        {"email": "c@hypermode.com"}
    ]
}

and header

X-Dgraph-AuthToken eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyLCJodHRwczovL2RncmFwaC5pby9qd3QvY2xhaW1zIjp7InJvbGUiOiJBRE1JTiJ9fQ.DHYBRLpXfGxntOWTDQObq8_0PrPZfn_xVMAFZqE_zCM

The first invocation is successful ( add)
The second invocation fails with

{
    "errors": [
        {
            "message": "mutation addUser failed because Dgraph execution failed because Some variables are declared multiple times.",
            "locations": [
                {
                    "line": 2,
                    "column": 3
                }
            ],
            "path": [
                "addUser"
            ]
        }
    ],
    "data": {
        "addUser": null
    },
    "extensions": {
        "touched_uids": 6,
        "tracing": {
            "version": 1,
            "startTime": "2024-08-15T19:42:35.509121642Z",
            "endTime": "2024-08-15T19:42:35.513617509Z",
            "duration": 4495877,
            "execution": {
                "resolvers": [
                    {
                        "path": [
                            "addUser"
                        ],
                        "parentType": "Mutation",
                        "fieldName": "addUser",
                        "returnType": "AddUserPayload",
                        "startOffset": 154632,
                        "duration": 4330005,
                        "dgraph": [
                            {
                                "label": "preMutationQuery",
                                "startOffset": 216753,
                                "duration": 3521409
                            },
                            {
                                "label": "mutation",
                                "startOffset": 4068519,
                                "duration": 0
                            },
                            {
                                "label": "query",
                                "startOffset": 0,
                                "duration": 0
                            }
                        ]
                    }
                ]
            }
        }
    }
}

[mwillfox]

@rderbier thank you so much for looking into this and opening the issue! Just to add my quick input - we are running into this currently in a production system and our workaround for now is to loop over our query and call it multiple times for lists. Obviously, this is not a great workaround for performance and I look forward to resolution! Thanks.