- Modified patch #43709 by chx, Eaton et al.: usability improvement: put some emphasis on the no trailing slash requirement.

sites/default/settings.php

@@ -89,16 +89,18 @@ $db_prefix = '';
 /**
  * Base URL:
  *
- * The URL to your Drupal installation. It is not allowed
- * to have a trailing slash; Drupal will add it for you.
+ * The URL to your Drupal installation.
  *
  * Examples:
  *   $base_url = 'http://www.example.com';
  *   $base_url = 'http://www.example.com:8888';
  *   $base_url = 'http://www.example.com/drupal';
  *   $base_url = 'https://www.example.com:8888/drupal';
+ *
+ * It is not allowed to have a trailing slash; Drupal will add it
+ * for you.
  */
-$base_url = 'http://www.example.com';
+$base_url = 'http://www.example.com';  // NO trailing slash!
 
 /**
  * PHP settings: