#813492 follow-up by chx, marcingy, c960657: Fixed HTTPS sessions use an invalid merge query.

includes/update.inc

@@ -582,6 +582,10 @@ function update_fix_d7_requirements() {
       variable_set('maintenance_mode_message', $message);
     }
 
+    // Add ssid column and index.
+    db_add_field('sessions', 'ssid', array('description' => "Secure session ID. The value is generated by PHP's Session API.", 'type' => 'varchar', 'length' => 64, 'not null' => TRUE, 'default' => ''));
+    db_add_index('sessions', 'ssid', array('ssid'));
+
     variable_set('update_d7_requirements', TRUE);
   }
 

modules/system/system.install

@@ -1414,14 +1414,14 @@ function system_schema() {
         'not null' => TRUE,
       ),
       'sid' => array(
-        'description' => "Primary key: A session ID. The value is generated by PHP's Session API.",
+        'description' => "A session ID. The value is generated by PHP's Session API.",
         'type' => 'varchar',
         'length' => 64,
         'not null' => TRUE,
         'default' => '',
       ),
       'ssid' => array(
-        'description' => "Unique key: Secure session ID. The value is generated by PHP's Session API.",
+        'description' => "Secure session ID. The value is generated by PHP's Session API.",
         'type' => 'varchar',
         'length' => 64,
         'not null' => TRUE,
@@ -1460,6 +1460,7 @@ function system_schema() {
     'indexes' => array(
       'timestamp' => array('timestamp'),
       'uid' => array('uid'),
+      'ssid' => array('ssid'),
     ),
     'foreign keys' => array(
       'uid' => array('users' => 'uid'),