Ticket #51656: wp-body-class-dark-mode.patch

src/wp-includes/post-template.php

@@ -785 +785 @@
                 $classes[] = 'wp-embed-responsive';
         }
 
+        if ( current_theme_supports( 'dark-theme' ) ) {
+                $classes[] = 'wp-dark-theme';
+        }
+
         $page = $wp_query->get( 'page' );
 
         if ( ! $page || $page < 2 ) {

src/wp-includes/theme.php

@@ -2482 +2482 @@
  * @since 5.5.0 The `core-block-patterns` feature was added and is enabled by default.
  * @since 5.5.0 The `custom-logo` feature now also accepts 'unlink-homepage-logo'.
  * @since 5.6.0 The `post-formats` feature warns if no array is passed.
+ * @since 5.7.0 The `dark-theme` feature was added.
  *
  * @global array $_wp_theme_features
  *
@@ -2490 +2491 @@
  *                        'html5', 'title-tag', 'customize-selective-refresh-widgets', 'starter-content',
  *                        'responsive-embeds', 'align-wide', 'dark-editor-style', 'disable-custom-colors',
  *                        'disable-custom-font-sizes', 'editor-color-palette', 'editor-font-sizes',
- *                        'editor-styles', 'wp-block-styles', and 'core-block-patterns'.
+ *                        'editor-styles', 'wp-block-styles', 'core-block-patterns', and 'dark-theme'.
  * @param mixed  ...$args Optional extra arguments to pass along with certain features.
  * @return void|bool False on failure, void otherwise.
  */