[Config] Array to string conversion error when saving row system config with defaults

[stollr]

Preconditions (*)

I am using Magento 2.4.0 in development mode with PHP 7.4.10 on Linux, Debian Buster.

Also verified and confirmed on 2.4-develop open source edition

Steps to reproduce (*)

1. We followed these instructions to create a dynamic row system config.

2. We have added default values to my etc/config.xml in this form:

     <default>
         <general>
             <quantity_ranges>
             <ranges>
                 <item1>
                     <from_qty>1</from_qty>
                     <to_qty>5</to_qty>
                     <price>10.00</price>
                     <tax>1</tax>
                 </item1>
                 <item2>
                     <from_qty>6</from_qty>
                     <to_qty>10</to_qty>
                     <price>20.00</price>
                     <tax>1</tax>
                 </item2>
                 <item3>
                     <from_qty>11</from_qty>
                     <to_qty>15</to_qty>
                     <price>30.00</price>
                     <tax>0</tax>
                 </item3>
             </ranges>
             </quantity_ranges>
         </general>
     </default>

3. Go to Admin -> System -> Configuration -> Quantity Ranges and click on the Save Config button

Expected result (*)

Save the configs.

Actual result (*)

I get the following error:

Notice: Array to string conversion in /path/to/magento/vendor/magento/framework/App/Config/Value.php on line 100

When I remove the defaults from the config.xml and clear the cache, the saving works correctly.

Notice

I have tried to debug the issue. What I found out so long is that Magento serializes the data in the config value to json in Magento\Config\Model\Config\Backend\Serialized::beforeSave and saves it in the data array.

In Magento\Framework\App\Config\Value::afterSave it calls $this->isValueChanged() where it compares $this->getValue() != $this->getOldValue(). Now in getOldValue it uses the default value coming from the XML config which is stored as array and is not serialized. At the point where the array is tried to be casted to a string, the error occures.

---

• 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 @Naitsirch. Thank you for your report.
To help us process this issue please make sure that you provided the following information:

• Summary of the issue
• Information on your environment
• Steps to reproduce
• Expected and actual results

Please make sure that the issue is reproducible on the vanilla Magento instance following Steps to reproduce. To deploy vanilla Magento instance on our environment, please, add a comment to the issue:

@magento give me 2.4-develop instance - upcoming 2.4.x release

For more details, please, review the Magento Contributor Assistant documentation.

Please, add a comment to assign the issue: @magento I am working on this

---

• 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, please join the Community Contributions Triage session to discuss the appropriate ticket.

🎥 You can find the recording of the previous Community Contributions Triage on the Magento Youtube Channel

✏️ Feel free to post questions/proposals/feedback related to the Community Contributions Triage process to the corresponding Slack Channel

[stollr]

@magento I am working on this

[wagento-rajan]

@magento I am working on this

[m2-assistant]

Hi @wagento-rajan! 👋
Thank you for collaboration. Only members of Community Contributors Team are allowed to be assigned to the issue. Please use @magento add to contributors team command to join Contributors team.

[stollr]

@wagento-rajan I have already created a PR for this issue ;-)

[m2-assistant]

Hi @engcom-Alfa. 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).

  Details

  If the issue has a valid description, the label Issue: Format is valid will be added to the issue automatically. Please, edit issue description if needed, until label Issue: Format is valid appears.

• 2. Verify that issue has a meaningful description and provides enough information to reproduce the issue. If the report is valid, add Issue: Clear Description label to the issue by yourself.

• 3. Add Component: XXXXX label(s) to the ticket, indicating the components 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-Alfa]

The issue is reproducible on fresh 2.4-develop.

Manual testing scenario:

1. We followed these instructions to create a dynamic row system config.

2. We have added default values to my etc/config.xml in this form:

     <default>
         <general>
             <quantity_ranges>
             <ranges>
                 <item1>
                     <from_qty>1</from_qty>
                     <to_qty>5</to_qty>
                     <price>10.00</price>
                     <tax>1</tax>
                 </item1>
                 <item2>
                     <from_qty>6</from_qty>
                     <to_qty>10</to_qty>
                     <price>20.00</price>
                     <tax>1</tax>
                 </item2>
                 <item3>
                     <from_qty>11</from_qty>
                     <to_qty>15</to_qty>
                     <price>30.00</price>
                     <tax>0</tax>
                 </item3>
             </ranges>
             </quantity_ranges>
         </general>
     </default>

3. Go to Admin -> System -> Configuration -> Quantity Ranges and click on the Save Config button

Actual Result: ✖️ got the following error:

[magento-engcom-team]

✅ Confirmed by @engcom-Alfa
Thank you for verifying the issue. Based on the provided information internal tickets MC-38588 were created

Issue Available: @engcom-Alfa, You will be automatically unassigned. Contributors/Maintainers can claim this issue to continue. To reclaim and continue work, reassign the ticket to yourself.

[magento-engcom-team]

Hi @Naitsirch. Thank you for your report.
The issue has been fixed in #30322 by @Naitsirch in 2.4-develop branch
Related commit(s):

• c0a9c422053ab85c4f3f77bb337196764c4ed149

The fix will be available with the upcoming 2.4.2 release.

[eikoncode]

Can you merge this PR in Magento 2.4.1 version also?

[CUTTRHOAT69]

If someone get this error and need a quick fix (without updating the Magento version or adding a patch) you can just add an serialized array on the config.xml file as the default field value. As Magento get the default info from XML as an array and does not have the format convertion you can just pass already as a serialized value.

Example:

<default>
    <general>
        <quantity_ranges>
            <ranges>
            {
                "item1":{"from_qty":"1","to_qty":"5","price":"10.00","tax":"1"},
                "item2":{"from_qty":"6","to_qty":"0","price":"20.00","tax":"1"},
                "item3":{"from_qty":"11","to_qty":"15","price":"30.00","tax":"0"}
            }
            </ranges>
        </quantity_ranges>
    </general>
</default>

Passing the value already as serialized the Magento getOldValue function doesn't need the conversion. The default values appear normally on the painel with the error fixed.
It's just works