- Patch #797680 by lyricnz, jbrown: drupal_write_record() unnecessarily sets primary keys while updating.

includes/common.inc

@@ -5955,6 +5955,12 @@ function drupal_write_record($table, &$record, $primary_keys = array()) {
       $serial = $field;
     }
 
+    // Skip field if it is in $primary_keys as it is unnecessary to update a
+    // field to the value it is already set to.
+    if (in_array($field, $primary_keys)) {
+      continue;
+    }
+
     if (!property_exists($object, $field)) {
       // Skip fields that are not provided, default values are already known 
       // by the database.

includes/path.inc

@@ -397,7 +397,7 @@ function path_save(&$path) {
   $path += array('pid' => NULL, 'language' => LANGUAGE_NONE);
 
   // Insert or update the alias.
-  $status = drupal_write_record('url_alias', $path, (!empty($path['pid']) ? 'pid' : NULL));
+  $status = drupal_write_record('url_alias', $path, (!empty($path['pid']) ? 'pid' : array()));
 
   // Verify that a record was written.
   if ($status) {