LibWeb: Layout the fieldset's rendered legend

[kostyafarber]

This fixes the legend position on my website :^) https://kostyafarber.com/about

with change:

without change:

[tcl3]

I've not looked at the code, but this causes regressions in the following WPT tests:

• http://wpt.live/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-calculating-min-max-content.html
• http://wpt.live/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/legend-inline-position-with-fieldset-padding.html
• http://wpt.live/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-baseline.html
• http://wpt.live/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-transform-translatez.html
• http://wpt.live/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/legend-position-relative-2.html

And fixes a failing subtest in this test::

• http://wpt.live/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/legend.html

It might be worth importing the improved test.

[kostyafarber]

Thanks for catching that out, I’ll have a look at those regressions then and see what’s going on.

I’ll import the fixed test.

[kostyafarber]

@tcl3 Update on the WPT tests. I've imported the passing test and I've worked through the first three.

• One and two were related to not setting and using shrink-fit correctly.
• Three is because now that fieldset establishes a BFC we need to create an anonymous wrapper box for it's content (as per the spec).

However the last two are how the newly positioned legend element interacts with the fieldset elements overflow when this property is set to hidden (i.e overflow: hidden;).

Please see images for the http://wpt.live/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-transform-translatez.html test below:

This branch:

Master:

Chrome:

It looks like we were initially passing because we just didn't position the legend correctly at all. However, I can't find anywhere in the spec on fieldset and legend that specifies how it should interact with overflow.

It would be good if somebody could suggest what we do in this case?

[nico]

(commit message: "Layout" is a noun, "Lay out" is the verb.)

[kostyafarber]

(commit message: "Layout" is a noun, "Lay out" is the verb.)

That it is, I will update.

[kostyafarber]

I've asked the discord but haven't got a response. I am wary to start implementing any feature (removing the legend from the clipped area) that isn't covered by the spec, as I've been told in the past that we should match reality and not just try pass wpt tests :^).

What is the ways forward here?