Links with query params with integer keys reset the keys

I've found this bug on a site today and patch in #4 works great.

The Needs Review Queue Bot → tested this issue.

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The patch in #4 resolves the issue. Created a MR.
mergeDeep is internally using mergeDeepArray with preserve integer keys set to FALSE by default.
In the patch we are passing it as TRUE to keep the keys as it is. Should be fine IMO.

This might need some tests.

@arisen seems you've created the branch but not the actual MR?

What would be the ideal place to add a Kernel Test for this?

  /**
   * Test Link element with integer key parameters
   */
  public function testLinkWithIntegerKeyParams() {
    $link_array = [
      '#type' => 'link',
      '#title' => 'foo',
      '#url' => Url::fromUri('internal:/my-page?myparam[2021]=2021'),
    ];
    $link_rendered = (string) \Drupal::service('renderer')->renderRoot($link_array);
    $expected_link = '<a href="/my-page?myparam%5B2021%5D=2021">foo</a>';
    $this->assertSame($expected_link, $link_rendered);
  }

Wondering if it can added as part of core/modules/system/tests/src/Kernel/Common/UrlTest.php or core/tests/Drupal/KernelTests/Core/Render/Element/RenderElementTypesTest.php

For the tests.

Ran the test only feature and it seemed to pass without the fix https://git.drupalcode.org/issue/drupal-3191456/-/jobs/707698 so not testing what we think it is. While updating please add :void to any new test function.

@smustgrave The issue is no longer reproducible on D11 but still existing on D10(checked on 10.2.2).

Seems like NestedArray::mergeDeep was not the root cause.
Looks like there has been some changes to the link preprocessing logic.

$options = NestedArray::mergeDeep($element['#url']->getOptions(), $element['#options']);
On D11, is an empty array so the issue is no longer occurring, whereas on D10 its having the params info same as $element['#url']->getOptions().

Then think we need some research about what issue was committed to 11 that didn’t get backported to 10 that fixed this issue.

@smustgrave found the issue 🐛 Query string duplications Fixed
It's already been added to 10.2 also.

Then this should be closed.

Note the related issue was merged 2 days ago so not in a tagged release yet