Changeset 62864

Timestamp:

07/28/2026 05:39:16 AM (17 hours ago)

Author:

ramonopoly

Message:

`
Layout: avoid resolving global settings for blocks with no layout output

This commit moves the global settings lookup in wp_render_layout_support_flag() below an early return for blocks with no layout support and no style attribute. Resolving settings on a cold cache queries the user's wp_global_styles post, which fires the_posts; a callback on that hook that renders blocks re-enters the filter and recurses without a base case.

Developed in: ​https://github.com/WordPress/wordpress-develop/pull/12729(​https://github.com/WordPress/wordpress-develop/pull/12729)

Props ramonopoly, andrewserong.

Fixes #65741.

Location:

trunk

Files:

• src/wp-includes/block-supports/layout.php (modified) (1 diff)
• tests/phpunit/tests/block-supports/layout.php (modified) (1 diff)

trunk/src/wp-includes/block-supports/layout.php

@@ -956 +956 @@
         static $global_styles = null;
 
-        $block_type               = WP_Block_Type_Registry::get_instance()->get_registered( $block['blockName'] );
-        $block_supports_layout    = block_has_support( $block_type, 'layout', false ) || block_has_support( $block_type, '__experimentalLayout', false );
-        $style_attr               = $block['attrs']['style'] ?? array();
+        $block_type            = WP_Block_Type_Registry::get_instance()->get_registered( $block['blockName'] );
+        $block_supports_layout = block_has_support( $block_type, 'layout', false ) || block_has_support( $block_type, '__experimentalLayout', false );
+        $style_attr            = $block['attrs']['style'] ?? array();
+        /*
+         * A block with no layout support and no style attribute at all cannot
+         * produce layout output, so return before resolving global settings.
+         *
+         * Resolving settings is not read-only: on a cold cache it queries the
+         * user's `wp_global_styles` post, which fires `the_posts`. A callback on
+         * that hook that renders blocks re-enters this filter, and the content it
+         * renders at that point is the global styles post itself, which parses to a
+         * single block with no name and no attributes. Without this return that
+         * block resolves settings again and the recursion has no base case.
+         */
+        if ( ! $block_supports_layout && empty( $style_attr ) ) {
+                return $block_content;
+        }
+
         $global_settings          = wp_get_global_settings();
         $viewport_settings        = $global_settings['viewport'] ?? null;

trunk/tests/phpunit/tests/block-supports/layout.php

@@ -1125 +1125 @@
                 );
         }
+
+        /**
+         * Tests that layout support returns early, without resolving global settings,
+         * for a block that cannot produce any layout output.
+         *
+         * Resolving global settings reads the user's `wp_global_styles` post with a
+         * `WP_Query`, which fires `the_posts`. A callback on that hook that renders
+         * blocks re-enters this filter, so the bail-out has to happen before the
+         * lookup or the recursion has no base case.
+         *
+         * @ticket 65741
+         *
+         * @covers ::wp_render_layout_support_flag
+         */
+        public function test_layout_support_flag_returns_early_before_resolving_global_settings() {
+                $user_data_resolutions = 0;
+                add_filter(
+                        'wp_theme_json_data_user',
+                        static function ( $theme_json ) use ( &$user_data_resolutions ) {
+                                ++$user_data_resolutions;
+                                return $theme_json;
+                        }
+                );
+
+                // A block with no layout support and no child layout, as produced by
+                // parsing content that has no block delimiters.
+                $block_content = '<p>Not a block.</p>';
+                $block         = array(
+                        'blockName' => null,
+                        'attrs'     => array(),
+                );
+
+                // Start from a cold cache, as on a front-end request.
+                wp_clean_theme_json_cache();
+
+                $this->assertSame(
+                        $block_content,
+                        wp_render_layout_support_flag( $block_content, $block ),
+                        'Block content should be returned unchanged when the block has no layout support.'
+                );
+                $this->assertSame(
+                        0,
+                        $user_data_resolutions,
+                        'Global settings should not be resolved for a block that cannot produce layout output.'
+                );
+
+                // A block that does support layout still resolves global settings, which
+                // confirms the assertion above is not passing because of a warm cache.
+                wp_clean_theme_json_cache();
+
+                wp_render_layout_support_flag(
+                        '<div class="wp-block-group"></div>',
+                        array(
+                                'blockName' => 'core/group',
+                                'attrs'     => array( 'layout' => array( 'type' => 'constrained' ) ),
+                        )
+                );
+
+                $this->assertGreaterThan(
+                        0,
+                        $user_data_resolutions,
+                        'Global settings should still be resolved for a block that supports layout.'
+                );
+        }
 }