Link render element overwrites CSS class

Here's a patch created on D10.3, but I suspect it applies fine to 11.x

Changes are made on on 11.x (our main development branch) first, and are then back ported as needed according to our policies.

Argh. Apparently core (and maybe contrib) creates attribute array class elements as both strings and arrays, so a cast to (array) is needed. I'd call that a bug, but that's another issue.

Here's a revised patch.

thank you for reporting

Fixes should be in MRs vs patches

Also will need a test case to show the problem.

I've just created a MR and added a Kernel test :)

1) Drupal\KernelTests\Core\Render\Element\RenderElementTypesTest::testLink
"#type 'link' anchor tag with extra classes in both ['#attributes'] and ['#options']['attributes']" input rendered correctly.
Failed asserting that an array is not empty.
/builds/issue/drupal-3494015/core/tests/Drupal/KernelTests/Core/Render/Element/RenderElementTypesTest.php:331
FAILURES!
Tests: 5, Assertions: 21, Failures: 1.

Shows test coverage, reviewing that file too looks like a good number of scenarios covered.

Rest of the change appears fine

Not sure if this requires a CR for merging 2 arrays now but will let committer decide.

While this is a bug fix it's also a minor behaviour change as mentioned in the IS, so only committing this to 11.x to avoid breaking existing sites in a patch release. The MR also doesn't apply cleanly to 10.5.x so only committing this to 11.x; if you think this is worthwhile to backport please reopen with an MR against 10.5.x.

Committed ee78cfa and pushed to 11.x. Thanks!

longwave → closed merge request !10860

Automatically closed - issue fixed for 2 weeks with no activity.