Rest cart item update throws `The requested qty is not available` if quantity in cart and quantity to update to exceeds stock

[sanderjongsma]

Preconditions and environment

• 2.4.7-p1
• Only for configurables
• Based on default instance with sample data

Steps to reproduce

1. Create guest cart with rest api:
   Post to https://11bfd466f8c258a1113feb50fd641584.instances-prod.magento-community.engineering/rest/V1/guest-carts/ and use that masked id.

2. Get the guest cart to determine quote id:
   Get to https://11bfd466f8c258a1113feb50fd641584.instances-prod.magento-community.engineering/rest/V1/guest-carts/{{masked_id}}

3. Add just 1 configurable to cart:
   Post to: https://11bfd466f8c258a1113feb50fd641584.instances-prod.magento-community.engineering/rest/V1/guest-carts/{{masked_id}}/items with body:

{
  "cartItem": {
    "sku": "MH02",
    "qty": 1,
    "quote_id": "{{quote_id}}",
    "product_option": {
      "extension_attributes": {
        "configurable_item_options": [
          {
            "option_id": "93",
            "option_value": 49
          },
          {
            "option_id": "142",
            "option_value": 166
          }
        ]
      }
    },
    "extension_attributes": {}
  }
}

4. Update the qty to 100 (default stock for a simple of a configurable product)
   

Note: Use the item_id of the configurable type (not the simple)

PUT to https://11bfd466f8c258a1113feb50fd641584.instances-prod.magento-community.engineering/rest/V1/guest-carts/{{masked_id}}/items/{{item_id}} with body:

{
  "cartItem": {
    "sku": "MH02",
    "qty": 100,
    "quote_id": "{{quote_id}}",
    "product_option": {
      "extension_attributes": {
        "configurable_item_options": [
          {
            "option_id": "93",
            "option_value": 49
          },
          {
            "option_id": "142",
            "option_value": 166
          }
        ]
      }
    },
    "extension_attributes": {}
  }
}

Now the response of the call is:

{
    "message": "The requested qty is not available"
}

Expected result

When doing step 4 the requested qty of 100 should be in the cart after the post request instead of an exception

Actual result

This exception is thrown in step 4:

{
    "message": "The requested qty is not available"
}

Additional information

while the actual stock is 100, so this should work. The error is thrown from this file: vendor/magento/module-inventory-sales/Model/IsProductSalableForRequestedQtyCondition/IsSalableWithReservationsCondition.php and after debugging it is because in this validator the $requestedQty is 101 instead of 100, so the requested quantity from the api call is added to the current quantity in the cart.

In \Magento\Quote\Model\Quote::updateItem on line 1805 there is a $buyRequest->setResetCount(true); to reset the actual counter, but when the reset_count is red in the request on line 94 here: \Magento\Quote\Model\Quote\Item\Processor::prepare there is another check: $item->getId() == $request->getId() which will be never true because the request does not have the id of the item.

Release note

No response

Triage and priority

• Severity: S0 - Affects critical data or functionality and leaves users without workaround.
• Severity: S1 - Affects critical data or functionality and forces users to employ a workaround.
• Severity: S2 - Affects non-critical data or functionality and forces users to employ a workaround.
• Severity: S3 - Affects non-critical data or functionality and does not force users to employ a workaround.
• Severity: S4 - Affects aesthetics, professional look and feel, “quality” or “usability”.

[m2-assistant]

Hi @sanderjongsma. Thank you for your report.
To speed up processing of this issue, make sure that the issue is reproducible on the vanilla Magento instance following Steps to reproduce. To deploy vanilla Magento instance on our environment, Add a comment to the issue:

• @magento give me 2.4-develop instance - upcoming 2.4.x release
• For more details, review the Magento Contributor Assistant documentation.
• Add a comment to assign the issue: @magento I am working on this
• To learn more about issue processing workflow, refer to the Code Contributions.

---

Join Magento Community Engineering Slack and ask your questions in #github channel.
⚠️ According to the Magento Contribution requirements, all issues must go through the Community Contributions Triage process. Community Contributions Triage is a public meeting.
🕙 You can find the schedule on the Magento Community Calendar page.
📞 The triage of issues happens in the queue order. If you want to speed up the delivery of your contribution, join the Community Contributions Triage session to discuss the appropriate ticket.

[m2-assistant]

Hi @engcom-Bravo. Thank you for working on this issue.
In order to make sure that issue has enough information and ready for development, please read and check the following instruction: 👇

• 1. Verify that issue has all the required information. (Preconditions, Steps to reproduce, Expected result, Actual result).
• 2. Verify that issue has a meaningful description and provides enough information to reproduce the issue.
• 3. Add Area: XXXXX label to the ticket, indicating the functional areas it may be related to.
• 4. Verify that the issue is reproducible on 2.4-develop branch
  Details

  - Add the comment @magento give me 2.4-develop instance to deploy test instance on Magento infrastructure.
  - If the issue is reproducible on 2.4-develop branch, please, add the label Reproduced on 2.4.x.
  - If the issue is not reproducible, add your comment that issue is not reproducible and close the issue and stop verification process here!
• 5. Add label Issue: Confirmed once verification is complete.
• 6. Make sure that automatic system confirms that report has been added to the backlog.

[engcom-Bravo]

@magento give me 2.4-develop instance

[magento-deployment-service]

Hi @engcom-Bravo. Thank you for your request. I'm working on Magento instance for you.

[magento-deployment-service]

Hi @engcom-Bravo, here is your Magento Instance: https://af74504e6ae991dcc1cb1e6019789fb1.instances-prod.magento-community.engineering
Admin access: https://af74504e6ae991dcc1cb1e6019789fb1.instances-prod.magento-community.engineering/admin_e8a4
Login: ce6f05eb
Password: 4f1aaf440e68

[engcom-Bravo]

Hi @sanderjongsma,

Thanks for your reporting and collaboration.

We have verified the issue in Latest 2.4-develop instance and it seems to be an expected behaviour of magento.

Since already the product is in cart with the QTY 1 and again we are adding more than available QTY it will shows an error The requested qty is not available which seems to be an expected behaviour.

Kindly let us know if we are missing anything.

Thanks.