Fix feature_value position backfill during 9.0.0 upgrade

[Codencode]

Questions	Answers
Description?	This PR fixes the PrestaShop 9.0.0 upgrade path for shops that already have feature values. When the new position column is added to feature_value, existing rows all receive the default value 0, which can cause ordering issues. This change adds a dedicated upgrade step that initializes sequential positions per feature during the 9.0.0 migration, while avoiding overwriting already-initialized data.
BC breaks?	yes
Deprecations?	yes
Fixed ticket?	Fixes PrestaShop/PrestaShop#41554
Sponsor company	Codencode snc
How to test?	1. Install PS version 8.x.x 2. Upgrade to PrestaShop 9.x.x 3. Check that the position field in the feature_value table is correctly populated and try changing the position of the values in the admin panel.

NOTE

The positions could also have been set using this query:

UPDATE ps_feature_value fv
INNER JOIN (
    SELECT
        id_feature_value,
        ROW_NUMBER() OVER (
            PARTITION BY id_feature
            ORDER BY id_feature_value ASC
        ) - 1 AS new_position
    FROM ps_feature_value
) x ON x.id_feature_value = fv.id_feature_value
SET fv.position = x.new_position;

However, I preferred to create a PHP file for compatibility reasons with different MySQL / MariaDB versions.

[kpodemski]

It seems not relevant to check for existence of this table, what do you think?

[Codencode]

Yes, you're right, I'll correct it.

[Codencode]

@kpodemski
I removed the checks on both the table and the field because we are sure they exist.

[Codencode]

@Quetzacoalt91 @kpodemski
Some files have the header/license in the old format, for example:
https://github.com/PrestaShop/autoupgrade/blob/dev/tests/integration/MarketplaceAndModuleCompatibilityTest.php

Should I fix them in this PR?

Also, I’m not sure whether targeting the dev branch was the right choice. Maybe I should have targeted the 7.6.x branch?

Also, there are errors (example: https://github.com/PrestaShop/autoupgrade/actions/runs/26496496929/job/78025905639?pr=1818) that do not depend on my change, perhaps precisely because I need to change branch?

[Quetzacoalt91]

Yes, can you please target the 7.6.x branch so your change can reach faster a stable release?

I've seen your how-to-test field, and can you tell me if that's solving an issue while using the shop?

[Codencode]

Yes, can you please target the 7.6.x branch so your change can reach faster a stable release?

@Quetzacoalt91, I performed the rebase, but I ran into some difficulties, so I had to do a reset and re-add the changes. That's why there's now only one commit, unlike before when there were two, but the final result is the same (the first commit, which was modified by the second, is missing).

I've seen your how-to-test field, and can you tell me if that's solving an issue while using the shop?

Yes, you can see the issue that explains in detail the problem visible in the admin: PrestaShop/PrestaShop#41554

[Quetzacoalt91]

I've the updated the base branch so the CI does not fail for a missing library canvas. Can you please rebase?

[Codencode]

@Quetzacoalt91 done

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[ingridusta]

Hi @Codencode,

Thanks for the catch !

I reproduced the bug :

And with ur fix :

Thanks ! It's QA approved ✅