- Patch #925490 by David_Rothstein: list_themes() should not call...

- Patch #925490 by David_Rothstein: list_themes() should not call file_exists() on each theme's info file.

includes/theme.inc

@@ -581,11 +581,7 @@ function list_themes($refresh = FALSE) {
     // Also check that the site is not in the middle of an install or update.
     if (!defined('MAINTENANCE_MODE')) {
       try {
-        foreach (system_list('theme') as $theme) {
-          if (file_exists($theme->filename)) {
-            $themes[] = $theme;
-          }
-        }
+        $themes = system_list('theme');
       }
       catch (Exception $e) {
         // If the database is not available, rebuild the theme data.