Add remaining changes from GB PR44363

src/wp-includes/class-wp-theme-json-resolver.php

@@ -283,12 +283,10 @@ public static function get_block_data() {
 		 *
 		 * @param WP_Theme_JSON_Data Class to access and update the underlying data.
 		 */
-		$theme_json = apply_filters( 'theme_json_blocks', new WP_Theme_JSON_Data( $config, 'core' ) );
+		$theme_json = apply_filters( 'theme_json_blocks', new WP_Theme_JSON_Data( $config, 'blocks' ) );
 		$config     = $theme_json->get_data();
 
-		// Core here means it's the lower level part of the styles chain.
-		// It can be a core or a third-party block.
-		return new WP_Theme_JSON( $config, 'core' );
+		return new WP_Theme_JSON( $config, 'blocks' );
 	}
 
 	/**

src/wp-includes/class-wp-theme-json.php

@@ -49,10 +49,12 @@ class WP_Theme_JSON {
 	 * The sources of data this object can represent.
 	 *
 	 * @since 5.8.0
+	 * @since 6.1.0 Added 'blocks'.
 	 * @var string[]
 	 */
 	const VALID_ORIGINS = array(
 		'default',
+		'blocks',
 		'theme',
 		'custom',
 	);

src/wp-includes/global-styles-and-settings.php

@@ -113,15 +113,21 @@ function wp_get_global_stylesheet( $types = array() ) {
 	}
 
 	/*
-	 * If variables are part of the stylesheet,
-	 * we add them for all origins (default, theme, user).
+	 * If variables are part of the stylesheet, then add them.
 	 * This is so themes without a theme.json still work as before 5.9:
 	 * they can override the default presets.
 	 * See https://core.trac.wordpress.org/ticket/54782
 	 */
 	$styles_variables = '';
 	if ( in_array( 'variables', $types, true ) ) {
-		$styles_variables = $tree->get_stylesheet( array( 'variables' ) );
+		/*
+		 * Only use the default, theme, and custom origins. Why?
+		 * Because styles for `blocks` origin are added at a later phase
+		 * (i.e. in the render cycle). Here, only the ones in use are rendered.
+		 * @see wp_add_global_styles_for_blocks
+		 */
+		$origins          = array( 'default', 'theme', 'custom' );
+		$styles_variables = $tree->get_stylesheet( array( 'variables' ), $origins );
 		$types            = array_diff( $types, array( 'variables' ) );
 	}
 
@@ -133,6 +139,12 @@ function wp_get_global_stylesheet( $types = array() ) {
 	 */
 	$styles_rest = '';
 	if ( ! empty( $types ) ) {
+		/*
+		 * Only use the default, theme, and custom origins. Why?
+		 * Because styles for `blocks` origin are added at a later phase
+		 * (i.e. in the render cycle). Here, only the ones in use are rendered.
+		 * @see wp_add_global_styles_for_blocks
+		 */
 		$origins = array( 'default', 'theme', 'custom' );
 		if ( ! $supports_theme_json ) {
 			$origins = array( 'default' );