Block Styles: Ensure unique classname generation for variations

This commit simplifies block style variation class name generation to ensure unique class names by replacing the hashing of block attributes in the block style variation class names with a call to `wp_unique_id`.

Doing so avoids potential for non-unique class names and conflicting styles when exact copies of a block are inserted via a repeated pattern.


Props aaronrobertshaw, martinkrcho, mukesh27, peterwilsoncc, ramonopoly.

Fixes #61877.



git-svn-id: https://develop.svn.wordpress.org/trunk@58951 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/block-supports/block-style-variations.php

@@ -7,21 +7,6 @@
  * @since 6.6.0
  */
 
-/**
- * Generate block style variation instance name.
- *
- * @since 6.6.0
- * @access private
- *
- * @param array  $block     Block object.
- * @param string $variation Slug for the block style variation.
- *
- * @return string The unique variation name.
- */
-function wp_create_block_style_variation_instance_name( $block, $variation ) {
-	return $variation . '--' . md5( serialize( $block ) );
-}
-
 /**
  * Determines the block style variation names within a CSS class string.
  *
@@ -124,7 +109,7 @@ function wp_render_block_style_variation_support_styles( $parsed_block ) {
 	 */
 	wp_resolve_block_style_variation_ref_values( $variation_data, $theme_json );
 
-	$variation_instance = wp_create_block_style_variation_instance_name( $parsed_block, $variation );
+	$variation_instance = wp_unique_id( $variation . '--' );
 	$class_name         = "is-style-$variation_instance";
 	$updated_class_name = $parsed_block['attrs']['className'] . " $class_name";
 
@@ -230,11 +215,9 @@ function wp_render_block_style_variation_class_name( $block_content, $block ) {
 
 	/*
 	 * Matches a class prefixed by `is-style`, followed by the
-	 * variation slug, then `--`, and finally a hash.
-	 *
-	 * See `wp_create_block_style_variation_instance_name` for class generation.
+	 * variation slug, then `--`, and finally an instance number.
 	 */
-	preg_match( '/\bis-style-(\S+?--\w+)\b/', $block['attrs']['className'], $matches );
+	preg_match( '/\bis-style-(\S+?--\d+)\b/', $block['attrs']['className'], $matches );
 
 	if ( empty( $matches ) ) {
 		return $block_content;

src/wp-includes/deprecated.php

@@ -6387,3 +6387,21 @@ function wp_enqueue_global_styles_custom_css() {
 		wp_add_inline_style( 'global-styles', $custom_css );
 	}
 }
+
+/**
+ * Generate block style variation instance name.
+ *
+ * @since 6.6.0
+ * @deprecated 6.7.0 Use `wp_unique_id( $variation . '--' )` instead.
+ *
+ * @access private
+ *
+ * @param array  $block     Block object.
+ * @param string $variation Slug for the block style variation.
+ *
+ * @return string The unique variation name.
+ */
+function wp_create_block_style_variation_instance_name( $block, $variation ) {
+	_deprecated_function( __FUNCTION__, '6.7.0', 'wp_unique_id' );
+	return $variation . '--' . md5( serialize( $block ) );
+}

tests/phpunit/tests/block-supports/wpCreateBlockStyleVariationInstanceName.php

@@ -13,6 +13,8 @@ class Tests_Block_Supports_WpCreateBlockStyleVariationInstanceName extends WP_Un
 	 * @ticket 61312
 	 *
 	 * @covers ::wp_create_block_style_variation_instance_name
+	 *
+	 * @expectedDeprecated wp_create_block_style_variation_instance_name
 	 */
 	public function test_block_style_variation_instance_name_generation() {
 		$block    = array( 'name' => 'test/block' );