Ticket #30830: 30830.diff

src/wp-admin/includes/template.php

@@ -1039 +1039 @@
                                                 continue;
                                         $i++;
                                         $hidden_class = in_array($box['id'], $hidden) ? ' hide-if-js' : '';
-                                        echo '<div id="' . $box['id'] . '" class="postbox ' . postbox_classes($box['id'], $page) . $hidden_class . '" ' . '>' . "\n";
+                                        $postbox_classes = postbox_classes($box['id'], $page);
+                                        if ( '' !== $postbox_classes ) {
+                                                $postbox_classes = ' ' . $postbox_classes;
+                                        }
+                                        echo '<div id="' . $box['id'] . '" class="postbox' . $postbox_classes . $hidden_class . '" ' . '>' . "\n";
                                         if ( 'dashboard_browser_nag' != $box['id'] )
                                                 echo '<div class="handlediv" title="' . esc_attr__('Click to toggle') . '"><br /></div>';
                                         echo "<h3 class='hndle'><span>{$box['title']}</span></h3>\n";