[Serializer] Fixing PHP warning in the ObjectNormalizer with MaxDepth enabled

[jaydiablo]

Q	A
Branch?	6.4
Bug fix?	yes
New feature?	no
Deprecations?	no
Issues	Fix #54378
License	MIT

This fixes a specific issue I ran into when testing an application in Symfony 6 that uses the rompetompe/inertia-bundle to serialize PHP data to JSON for use by Inertia.js.

Added a test that is as minimal as necessary for the Warning to be thrown. I tested against Symfony 5.4 as well, but the issue doesn't seem to be present there (could have something to do with 5.4 not having the AttributeLoader).

[derrabus]

Can you elaborate a bit on how your fix works? I don't understand it. 😓

[stof]

What happens if attributesMetadata has an entry only for a different attribute ? null === $maxDepth = $attributesMetadata[$attribute]?->getMaxDepth() would still trigger a warning in such case.

To me, the right fix would be handle properly the case where there is no $attribute key in the array.

[jaydiablo]

Regarding the test failure, I'm not sure why that Redis test is failing now, perhaps something in the dependencies updated?

I removed my fix and ran just that test, fails with or without my fix in place, so don't believe it's a result of the change to this PR.

[jaydiablo]

Status: Needs Review

[dunglas]

Could be:

Suggested change

	|| !isset($attributesMetadata[$attribute]) || null === $maxDepth = $attributesMetadata[$attribute]?->getMaxDepth()
	|| null === $maxDepth = ($attributesMetadata[$attribute]?->getMaxDepth() ?? null)

[jaydiablo]

The warning is still thrown in that case as $attributesMetadata[$attribute] is still trying to be accessed.

[fabpot]

@jaydiablo This PR must be rebased to get rid of the merge commits.

[jaydiablo]

@fabpot rebased

[nicolas-grekas]

Thank you @jaydiablo.