AJAX pager doesn't work with exposed filter which has a default value

I ran into a similar problem that patch #2 provided helped with. This issue seems to be present for exposed combined fields filters with no value when applied to a view as well.

Steps I took to reproduce the same issue:

1. Create a Content type and add 10 Nodes.
2. Create a View as an unformatted list
3. Add a block Display
4. Enable Ajax for the view
5. Add a combined fields filter that is exposed and searching 2 more fields on the content type
6. Set Exposed Filters to be "Input Required"
7. Configure the new view block to be visible on the site somewhere and traverse to it
8. Apply the exposed filters to the view with no values set so that all results display
9. Paginate to the second page

The list of results should disappear. I encountered this bug across a couple of different Drupal 9 sites, so I rerolled the patch for 9.3.x

Simplifying the tags a little.

Updating formatting to pass the code quality checks.

fixed linting issues in patch, Rerolled patch #9, Attached interdiff for same. please review.

I re-rolled #10 to work on 9.5.1. The only difference seems to be a blank line? Not sure why that made it not apply but this one does.

Fixed CCF for 9.5.x in #16.

Attaching patch for the latest version. I haven't succeeded with tests so far, will get back to them later.

I have fixed the CC failure, attached interdiff for same. please review

Thanks for the proper update. I've added fix for tests.

Believe this still needs a test for the exact problem.

Updating the failing test I don't believe covers the change. &title= is not a default value that I can tell and actually probably shouldn't be in the URL I think if no value is present.

Attaching patch with new test case.
About &title= part, I've tested following case - I updated 'test_content_ajax' view and switched off AJAX option and checked URLs and this part was presented. So, I assume this as normal behaviour, as non-AJAX view has the same URL.

Sorry for the a bit wrong patch. Attaching proper one.

Attaching patch with the fix for tests.

Fixing wrong function call.

Believe this is ready! Thanks for adding that additional test!

I'm triaging RTBC issues. I re-read the IS and the comments. I didn't find any unanswered questions. But there is not a failing test to prove the change works.

Reading the patch I have questions about the tests.

1. +++ b/core/modules/views/tests/src/FunctionalJavascript/PaginationAJAXTest.php
   @@ -46,7 +46,12 @@ protected function setUp(): void {
   +        'title' => $i > 6 ? 'Node ' . $i . ' content' : 'Node ' . $i . ' content default_value',
   

   This is changing the source for the current tests for node 7 -> 11. Does this mean we are losing test coverage?

2. +++ b/core/modules/views/tests/src/FunctionalJavascript/PaginationAJAXTest.php
   @@ -46,7 +46,12 @@ protected function setUp(): void {
   +        'type' => 'page',
   

   Why is this needed?

So the new test is largely a duplicate of the existing one. And it looks like some refactoring could make the differences between the two tests easier to see. But that is probably out of scope. Plus, it is better to fix the bug and have a followup than to hold this up. What would help is a comment in the setup to explain the need for the later nodes to be different.

However, I am not setting this to Needs works. I will leave at RTBC and let another committer make the decision because I don't work with FuncationalJavascript tests.

#33.1 I don't think we've lost test coverage, the existing tests have been updated.
#33.2 Fixed on commit.

Committed d251a98 and pushed to 11.x. Also backported to 10.1.x as a non-disruptive bug fix. Thanks!