updated core to 7.58, security update

includes/database/schema.inc

@@ -92,7 +92,8 @@ require_once dirname(__FILE__) . '/query.inc';
  *    specification). Each specification is an array containing the name of
  *    the referenced table ('table'), and an array of column mappings
  *    ('columns'). Column mappings are defined by key pairs ('source_column' =>
- *    'referenced_column').
+ *    'referenced_column'). This key is for documentation purposes only; foreign
+ *    keys are not created in the database, nor are they enforced by Drupal.
  *  - 'indexes':  An associative array of indexes ('indexname' =>
  *    specification). Each specification is an array of one or more
  *    key column specifiers (see below) that form an index on the
@@ -144,6 +145,8 @@ require_once dirname(__FILE__) . '/query.inc';
  *   'unique keys' => array(
  *     'vid' => array('vid'),
  *   ),
+ *   // For documentation purposes only; foreign keys are not created in the
+ *   // database.
  *   'foreign keys' => array(
  *     'node_revision' => array(
  *       'table' => 'node_revision',
@@ -161,6 +164,9 @@ require_once dirname(__FILE__) . '/query.inc';
  * @see drupal_install_schema()
  */
 
+/**
+ * Base class for database schema definitions.
+ */
 abstract class DatabaseSchema implements QueryPlaceholderInterface {
 
   protected $connection;
@@ -288,7 +294,7 @@ abstract class DatabaseSchema implements QueryPlaceholderInterface {
   protected function buildTableNameCondition($table_name, $operator = '=', $add_prefix = TRUE) {
     $info = $this->connection->getConnectionOptions();
 
-    // Retrive the table name and schema
+    // Retrieve the table name and schema
     $table_info = $this->getPrefixInfo($table_name, $add_prefix);
 
     $condition = new DatabaseCondition('AND');