[aaronrobertshaw]

Backport of Gutenberg PR WordPress/gutenberg#86164

Trac ticket: https://core.trac.wordpress.org/ticket/66438

Fixes a block style variation text color being hidden when the block type sets a text gradient. Reported in WordPress/gutenberg#84599.

This PR backports:

• the private text_clip_base_blocks option for WP_Theme_JSON::get_stylesheet(),
• the text clip escape in the variation's main, breakpoint and pseudo-state rules,
• passing the merged block type styles from wp_render_block_style_variation_support_styles(),
• and the accompanying block style variation and WP_Theme_JSON tests.

The editor side of the fix arrives later with the Gutenberg package update.

Overlap: #15432 changes the same block style variation rules in WP_Theme_JSON::get_styles_for_block(), so whichever of the two merges second needs a small rebase that keeps $text_clip_base_block_styles in the variation and breakpoint text clip bases. #15433 touches nearby lines in class-wp-theme-json.php but merges cleanly with this PR.

Testing instructions

Note

Only the front end is fixed in this PR. The editor still shows the gradient until the Gutenberg package update. Check the front end.

1. Activate a block theme.
2. Add this to a plugin or functions.php:

register_block_style( 'core/paragraph', array(
	'name'       => 'green-text',
	'label'      => 'Green text',
	'style_data' => array( 'color' => array( 'text' => '#00aa00' ) ),
) );
add_filter( 'wp_theme_json_data_theme', function ( $theme_json ) {
	return $theme_json->update_with( array(
		'version' => 3,
		'styles'  => array( 'blocks' => array( 'core/paragraph' => array(
			'background' => array(
				'gradient'       => 'linear-gradient(90deg, #ff0000 0%, #0000ff 100%)',
				'backgroundClip' => 'text',
			),
		) ) ),
	) );
} );

3. Add a Paragraph to a post, select the Green text style and publish it. The editor canvas still shows the gradient, which is expected.
4. View the post. The paragraph text should be solid green, not the red to blue gradient.
5. Inspect the block-style-variation-styles-inline-css style tag. It should contain a rule like this (the number suffix can differ):

:root :where(p.is-style-green-text--1){color: #00aa00;-webkit-text-fill-color: currentColor;}

On trunk the rule has no -webkit-text-fill-color, and the gradient still paints the letters.

Use of AI

AI assistance: Yes
Tool(s): Claude Code
Model(s): Claude Opus 5.5
Used for: The mechanical port, tests and this description.

[github-actions]

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[aaronrobertshaw]

This should be ready for review.

One thing to note: #15432 changes the same variation rules, so whichever lands second needs a small rebase.

[github-actions]

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Props aaronrobertshaw.

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[ramonjd]

Compared PR with Gutenberg #86164 === matches.

wp_ prefixes / @ticket 66438 annotations / tests pass for me locally too

Thanks!

Two notes:

• Assuming this should land before #15432. At the very least it keeps the Gutenberg merge order, and #15432 then adds $text_clip_base_block_styles back to its two variation base lists.
• We should wait until trunk opens for 7.3.