Ticket #32002: 32002.1.patch

src/wp-includes/class-wp-customize-control.php

@@ -1245 +1245 @@
                 $current_url = set_url_scheme( 'http://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'] );
                 $preview_url = esc_url( add_query_arg( 'theme', '__THEME__', $current_url ) ); // Token because esc_url() strips curly braces.
                 $preview_url = str_replace( '__THEME__', '{{ data.theme.id }}', $preview_url );
+
+                // Doesn't work, because $this->theme is empty
+                $is_active_theme = $this->theme->stylesheet === $this->manager->original_stylesheet;
                 ?>
                 <div class="theme" tabindex="0" data-preview-url="<?php echo esc_attr( $preview_url ); ?>" aria-describedby="{{ data.theme.id }}-action {{ data.theme.id }}-name">
                         <# if ( data.theme.screenshot[0] ) { #>

src/wp-includes/class-wp-customize-manager.php

@@ -33 +33 @@
          *
          * @var string
          */
-        protected $original_stylesheet;
+        public $original_stylesheet;
 
         /**
          * Whether this is a Customizer pageload.
@@ -1198 +1198 @@
                 require_once( ABSPATH . 'wp-admin/includes/theme.php' );
 
                 // Theme Controls.
+
+                if ( ! $this->is_theme_active() ) {
+                        /*
+                         * Add a control for the active/original theme.
+                         * The first array element of wp_prepare_themes_for_js() is empty,
+                         * because it's reserved for the current theme. But we want
+                         * prepared data for just one theme...
+                         */
+                        $active_theme = current( array_filter( wp_prepare_themes_for_js( array( wp_get_theme( $this->original_stylesheet ) ) ) ) );
+                        $this->add_control( new WP_Customize_Theme_Control( $this, $active_theme['id'], array(
+                                'theme'    => $active_theme,
+                                'section'  => 'themes',
+                                'settings' => 'active_theme',
+                        ) ) );
+                }
+
                 $themes = wp_prepare_themes_for_js();
                 foreach ( $themes as $theme ) {
-                        if ( $theme['active'] ) {
+                        if ( $theme['active'] || $theme['stylesheet'] === $this->original_stylesheet ) {
                                 continue;
                         }