filter_autop should ignore twig.config debug html comments

Tests showing this is failing with:

<p>Text here
<!-- THEME DEBUG -->
<!-- THEME HOOK: 'html' -->
<!-- FILE NAME SUGGESTIONS:
* html--node.html.twig
x html.html.twig -->
<span>Test</span></p>

Results in:

<p>Text here</p>
<!-- THEME DEBUG -->
<!-- THEME HOOK: 'html' -->
<!-- FILE NAME SUGGESTIONS:
* html--node.html.twig
x html.html.twig -->
<p><span>Test</span></p>

Note that when you have twig debug enabled, line breaks are always added before and after the nested twig template, even with {% apply spaceless %}{% end apply %}

Okay this handles it now. Avoided regex here as its getting overly complicated given the regex would need to work across lines. Figured it is more straightforward and readable to check subsequent and preceding lines.

To test this out, without change to filter.module, this now fails:

./vendor/bin/phpunit -c core/phpunit.xml --debug core/modules/filter/tests/src/Kernel/FilterKernelTest.php --filter=testLineBreakFilter

With the change to filter.module, it passes.

Thanks for the quick review! Applied your suggestions, looks like this is ready to go then. Thanks!

Updating issue summary to mark all as completed as well (forgot!)

Thanks for flagging. I updated the filter to cover that now + added an additional bit to the test.

I think I did grab all from 11.x and merge it in. Isn't the squashing of commits happening when this eventually gets merged in? Probably I am not understanding what you are asking @smustgrave sorry :)

Ah I see, thanks!

Ah nice, handy feature; saw that 'Downstream failure' and got curious. Thanks for jumping in and helping get this one ready again!

@catch added a suggested route instead of making it more generic - what do you think?

Great thank you both!