Duotone: Only output Duotone filters that are used

lib/class-wp-theme-json-gutenberg.php

@@ -567,6 +567,11 @@ public static function get_element_class_name( $element ) {
 	 */
 	const LATEST_SCHEMA = 2;
 
+	/**
+	 * An array of Duotone presets.
+	 */
+	static $duotone_presets;
+
 	/**
 	 * Constructor.
 	 *
@@ -2266,6 +2271,11 @@ private static function get_block_nodes( $theme_json, $selectors = array() ) {
 		return $nodes;
 	}
 
+	private function gutenberg_get_preset_slug_from_declaration( $declaration ) {
+		preg_match('/var\(--wp--preset--duotone--(.*)\)/', $declaration['value'], $matches );
+		return $matches[1];
+	}
+
 	/**
 	 * Gets the CSS rules for a particular block from theme.json.
 	 *
@@ -2425,8 +2435,10 @@ function( $pseudo_selector ) use ( $selector ) {
 		$declarations_duotone = array();
 		foreach ( $declarations as $index => $declaration ) {
 			if ( 'filter' === $declaration['name'] ) {
-				unset( $declarations[ $index ] );
+				$filter_preset_slug = $this->gutenberg_get_preset_slug_from_declaration( $declarations[ $index ] );
+				self::$duotone_presets[] = $filter_preset_slug;
 				$declarations_duotone[] = $declaration;
+				unset( $declarations[ $index ] );
 			}
 		}
 
@@ -2700,7 +2712,9 @@ public function get_svg_filters( $origins ) {
 					continue;
 				}
 				foreach ( $duotone_presets[ $origin ] as $duotone_preset ) {
-					$filters .= wp_get_duotone_filter_svg( $duotone_preset );
+					if ( in_array( $duotone_preset['slug'], self::$duotone_presets ) ) {
+						$filters .= wp_get_duotone_filter_svg( $duotone_preset );
+					}
 				}
 			}
 		}
@@ -3449,4 +3463,5 @@ public function set_spacing_sizes() {
 
 		_wp_array_set( $this->theme_json, array( 'settings', 'spacing', 'spacingSizes', 'default' ), $spacing_sizes );
 	}
+
 }

lib/compat/wordpress-6.2/get-global-styles-and-settings.php

@@ -255,3 +255,45 @@ function _gutenberg_add_non_persistent_theme_json_cache_group() {
 	wp_cache_add_non_persistent_groups( 'theme_json' );
 }
 add_action( 'plugins_loaded', '_gutenberg_add_non_persistent_theme_json_cache_group' );
+
+
+/**
+ * Returns a string containing the SVGs to be referenced as filters (duotone).
+ *
+ * @since 5.9.1
+ *
+ * @return string
+ */
+function gutenberg_get_global_styles_svg_filters() {
+	/*
+	 * Ignore cache when `WP_DEBUG` is enabled, so it doesn't interfere with the theme
+	 * developer's workflow.
+	 *
+	 * @todo Replace `WP_DEBUG` once an "in development mode" check is available in Core.
+	 */
+	$can_use_cached = ! WP_DEBUG;
+	$cache_group    = 'theme_json';
+	$cache_key      = 'wp_get_global_styles_svg_filters';
+	if ( $can_use_cached ) {
+		$cached = wp_cache_get( $cache_key, $cache_group );
+		if ( $cached ) {
+			return $cached;
+		}
+	}
+
+	$supports_theme_json = wp_theme_has_theme_json();
+
+	$origins = array( 'default', 'theme', 'custom' );
+	if ( ! $supports_theme_json ) {
+		$origins = array( 'default' );
+	}
+
+	$tree = WP_Theme_JSON_Resolver_Gutenberg::get_merged_data();
+	$svgs = $tree->get_svg_filters( $origins );
+
+	if ( $can_use_cached ) {
+		wp_cache_set( $cache_key, $svgs, $cache_group );
+	}
+
+	return $svgs;
+}

lib/compat/wordpress-6.2/script-loader.php

@@ -191,3 +191,38 @@ function gutenberg_enqueue_global_styles_custom_css() {
 	}
 }
 add_action( 'wp_enqueue_scripts', 'gutenberg_enqueue_global_styles_custom_css' );
+
+
+
+/**
+ * Renders the SVG filters supplied by theme.json.
+ *
+ * Note that this doesn't render the per-block user-defined
+ * filters which are handled by wp_render_duotone_support,
+ * but it should be rendered before the filtered content
+ * in the body to satisfy Safari's rendering quirks.
+ *
+ * @since 5.9.1
+ */
+function gutenberg_global_styles_render_svg_filters() {
+	/*
+	 * When calling via the in_admin_header action, we only want to render the
+	 * SVGs on block editor pages.
+	 */
+	if (
+		is_admin() &&
+		! get_current_screen()->is_block_editor()
+	) {
+		return;
+	}
+
+	$filters = gutenberg_get_global_styles_svg_filters();
+	if ( ! empty( $filters ) ) {
+		echo $filters;
+	}
+}
+
+remove_action( 'wp_body_open', 'wp_global_styles_render_svg_filters' );
+remove_action( 'in_admin_header', 'wp_global_styles_render_svg_filters' );
+add_action( 'wp_body_open', 'gutenberg_global_styles_render_svg_filters' );
+add_action( 'in_admin_header', 'gutenberg_global_styles_render_svg_filters' );