Correctly handle dark icons in data-icon and data-icon-disabled

[zoglo]

Fixes #6869

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Description

I extract the incoming data-attributes and properly distribute them for the two states now, this has been missing before.
Attributes get merged again but I remove the data-icons from the HtmlAttributes before doing so.

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Edit

• Just replacing the icon sources within darkAttributes works

[zoglo]

/cc @leofeyer - Should we change this to 5.3 then as 5.2.9 has already been released?

[leofeyer]

Yes please.

[leofeyer]

Would it not be much shorter if we just added the following in line 210?

foreach (array('data-icon', 'data-icon-disabled') as $icon)
{
	if (isset($darkAttributes[$icon]))
	{
		$pathinfo = pathinfo($darkAttributes[$icon]);
		$darkAttributes[$icon] = $pathinfo['filename'] . '--dark.' . $pathinfo['extension'];
	}
}

contao/core-bundle/contao/library/Contao/Image.php

Lines 207 to 209 in e2ea04c

	$darkAttributes = new HtmlAttributes($attributes);
	$darkAttributes->mergeWith(array('class' => 'color-scheme--dark', 'loading' => 'lazy'));

[zoglo]

leofeyer it's ready to review, just wanted to make sure and test it once again

[zoglo]

Would it not be much shorter if we just added the following in line 210?

Guess after trying out multiple approaches, I didn't see this. That works as well @leofeyer, you are right.

[leofeyer]

Thank you @zoglo.