[config] load fails if libxml_disable_entity_loader is globally set to true

[krichprollsch]

If a libxml_disable_entity_loader is set to true somewhere, the xml parsing fails after a cache directory deletion with the error:

[WARNING 1549] failed to load external entity "file:////home/pierre/project/vendor/symfony/symfony/src/Symfony/Component/DependencyInjection/Loader/schema/dic/services/services-1.0.xsd" (in n/a - line 0, column 0)
[WARNING 3084] Element '{http://www.w3.org/2001/XMLSchema}import': Failed to locate a schema at location 'file:////home/pierre/project/vendor/symfony/symfony/src/Symfony/Component/DependencyInjection/Loader/schema/dic/services/services-1.0.xsd'. Skipping the import. (in in_memory_buffer - line 8, column 0)
[ERROR 1845] Element '{http://symfony.com/schema/dic/services}container': No matching global declaration available for the validation root. (in /home/pierre/project/web/ - line 5, column 0)

You can reproduce with a fresh install of symfony and a bundle using xml config.
Add a libxml_disable_entity_loader(true); before the kernel boot and remove the cache directory.

The issue exists only via a web request, the console cli is not impacted.

Im not sure how to fix the problem. We could force libxml_disable_entity_loader(false) before the xml validation test [1] as it appears to be required, and reset the value after.

[xabbuh]

@krichprollsch Can you confirm that the fix from #18908 fixes your issue?

[krichprollsch]

yes it is 👍