Concurrent modification error on csv update for order line item transition

[Oehmi]

Description / Current behavior

When updating the line item state of more than one line item within an order, a error is thrown for all line items except the first.
"message": "Version mismatch. Concurrent modification.",

After first analysis, the concurrent modification error seems to be caused due to the fact the two line items were not merged to one object, resulting in two order update runs with two concurrent requests to update one order.

[junajan]

Problematic CSV:

orderNumber,lineItemId,quantity,fromState,toState,actualTransitionDate,_fromStateQty
B-QCG-JPG-CKF,8caec80a-4e62-4d54-8b6a-b53b2d388499,1,picking,picked,2017-11-14T14:17:18+01:00,1
B-QCG-JPG-CKF,a6a20f73-2f45-403c-99d2-4632425321a8,1,open,picking,2017-11-14T14:17:18+01:00,1

Converted to JSON by csv-parser-orders module:

[
    {
        "lineItems": [
            {
                "id": "8caec80a-4e62-4d54-8b6a-b53b2d388499",
                "state": [
                    {
                        "_fromStateQty": 1,
                        "fromState": "picking",
                        "quantity": 1,
                        "toState": "picked"
                    }
                ]
            }
        ],
        "orderNumber": "B-QCG-JPG-CKF"
    },
    {
        "lineItems": [
            {
                "id": "a6a20f73-2f45-403c-99d2-4632425321a8",
                "state": [
                    {
                        "_fromStateQty": 1,
                        "fromState": "open",
                        "quantity": 1,
                        "toState": "picking"
                    }
                ]
            }
        ],
        "orderNumber": "B-QCG-JPG-CKF"
    }
]

Error report

{
    "errors": [
        {
            "error": {
                "body": {
                    "errors": [
                        {
                            "code": "ConcurrentModification",
                            "currentVersion": 8,
                            "message": "Version mismatch. Concurrent modification."
                        }
                    ],
                    "message": "Version mismatch. Concurrent modification.",
                    "originalRequest": {
                        "endpoint": "/orders/f03703a5-c2e3-49e0-ae7a-206c50612cad",
                        "options": {
                            "config": {
                                "project_key": "project-key"
                            },
                            "protocol": "https",
                            "rejectUnauthorized": true,
                            "timeout": 20000,
                        },
                        "payload": {
                            "actions": [
                                {
                                    "action": "transitionLineItemState",
                                    "fromState": {
                                        "id": "da974709-3507-4c79-bbe3-147dfa508f8e",
                                        "typeId": "state"
                                    },
                                    "lineItemId": "8caec80a-4e62-4d54-8b6a-b53b2d388499",
                                    "quantity": 1,
                                    "toState": {
                                        "id": "796cc851-fbb2-46c9-89b6-f75fda4145d0",
                                        "typeId": "state"
                                    }
                                }
                            ],
                            "version": 7
                        }
                    },
                    "statusCode": 409
                },
                "code": 409,
                "message": "Version mismatch. Concurrent modification.",
                "name": "ConcurrentModification",
                "stack": "ConcurrentModification: Version mismatch. Concurrent modification.",
                "statusCode": 409
            },
            "order": {
                "lineItems": [
                    {
                        "id": "8caec80a-4e62-4d54-8b6a-b53b2d388499",
                        "state": [
                            {
                                "fromState": "picking",
                                "quantity": 1,
                                "toState": "picked"
                            }
                        ]
                    }
                ],
                "orderNumber": "B-QCG-JPG-CKF"
            }
        }
    ],
    "inserted": [
        "B-QCG-JPG-CKF"
    ],
    "successfullImports": 1
}