Ticket #18599: 18599.2.patch

wp-admin/includes/class-wp-themes-list-table.php

@@ -175 +175 @@
 ?>
                 <a href="<?php echo $preview_link; ?>" class="<?php echo $thickbox_class; ?> screenshot">
 <?php if ( $screenshot ) : ?>
-                        <img src="<?php echo $theme_root_uri . '/' . $stylesheet . '/' . $screenshot; ?>" alt="" />
+                        <img src="<?php echo esc_url( _get_theme_screenshot_url( $theme_root, $theme_root_uri, $template, $stylesheet, $screenshot ) ); ?>" alt="" />
 <?php endif; ?>
                 </a>
 <h3><?php

wp-admin/themes.php

@@ -81 +81 @@
 <h3><?php _e('Current Theme'); ?></h3>
 <div id="current-theme">
 <?php if ( $ct->screenshot ) : ?>
-<img src="<?php echo $ct->theme_root_uri . '/' . $ct->stylesheet . '/' . $ct->screenshot; ?>" alt="<?php _e('Current theme preview'); ?>" />
+<img src="<?php echo esc_url( _get_theme_screenshot_url( $ct->theme_root, $ct->theme_root_uri, $ct->template, $ct->stylesheet, $ct->screenshot ) ); ?>" alt="<?php _e('Current theme preview'); ?>" />
 <?php endif; ?>
 <h4><?php
         /* translators: 1: theme title, 2: theme version, 3: theme author */

wp-includes/theme.php

@@ -295 +295 @@
 
                 $screenshot = false;
                 foreach ( array('png', 'gif', 'jpg', 'jpeg') as $ext ) {
-                        if (file_exists("$theme_root/$stylesheet/screenshot.$ext")) {
+                        if ( file_exists("$theme_root/$stylesheet/screenshot.$ext") || file_exists("$theme_root/$template/screenshot.$ext") ) {
                                 $screenshot = "screenshot.$ext";
                                 break;
                         }
@@ -1989 +1989 @@
 
 add_action( 'delete_attachment', '_delete_attachment_theme_mod' );
 
+/**
+ * Retrieve screenshot URL for a theme.
+ *
+ * If a child theme screenshot is missing, the one from a parent theme is used.
+ *
+ * @access private
+ * @since 3.3.0
+ */
+function _get_theme_screenshot_url( $theme_root, $theme_root_uri, $template, $stylesheet, $screenshot ) {
+        $screenshot_url = false;
+
+        if ( file_exists("$theme_root/$stylesheet/$screenshot") )
+                $screenshot_url = "$theme_root_uri/$stylesheet/$screenshot";
+        elseif ( file_exists("$theme_root/$template/$screenshot") )
+                $screenshot_url = "$theme_root_uri/$template/$screenshot";
+
+        return $screenshot_url;
+}
+
 ?>