Index: src/wp-admin/themes.php
===================================================================
--- src/wp-admin/themes.php	(revision 31100)
+++ src/wp-admin/themes.php	(working copy)
@@ -168,10 +168,12 @@
 			if ( !empty($submenu[$item[2]]) ) {
 				$submenu[$item[2]] = array_values($submenu[$item[2]]); // Re-index.
 				$menu_hook = get_plugin_page_hook($submenu[$item[2]][0][2], $item[2]);
-				if ( file_exists(WP_PLUGIN_DIR . "/{$submenu[$item[2]][0][2]}") || !empty($menu_hook))
-					$current_theme_actions[] = "<a class='button button-secondary$class' href='admin.php?page={$submenu[$item[2]][0][2]}'>{$item[0]}</a>";
-				else
+				if ( file_exists( WP_PLUGIN_DIR . "/{$submenu[$item[2]][0][2]}" ) || !empty( $menu_hook ) ) {
+					$href = esc_url( add_query_arg( array( 'page' => $submenu[$item[2]][0][2] ), 'admin.php' ) );
+					$current_theme_actions[] = "<a class='button button-secondary$class' href='" . $href . "'>{$item[0]}</a>";
+				} else {
 					$current_theme_actions[] = "<a class='button button-secondary$class' href='{$submenu[$item[2]][0][2]}'>{$item[0]}</a>";
+				}
 			} elseif ( ! empty( $item[2] ) && current_user_can( $item[1] ) ) {
 				$menu_file = $item[2];