commit 7d4c440f897e200e987d97d426c90622e1ad3e20
Author: Lorenz Schori <lo@znerol.ch>
Date:   Tue Sep 25 19:09:39 2012 +0200

    Issue #1266572 by znerol, Damien Tournoud: workaround in SQLite causes some update to be missed.

diff --git a/includes/database/sqlite/query.inc b/includes/database/sqlite/query.inc
index 74ff9ba..1bf609d 100644
--- a/includes/database/sqlite/query.inc
+++ b/includes/database/sqlite/query.inc
@@ -57,39 +57,18 @@ class InsertQuery_sqlite extends InsertQuery {
  * we don't select those rows.
  *
  * A query like this one:
- *   UPDATE test SET name = 'newname' WHERE tid = 1
+ *   UPDATE test SET col1 = 'newcol1', col2 = 'newcol2' WHERE tid = 1
  * will become:
- *   UPDATE test SET name = 'newname' WHERE tid = 1 AND name <> 'newname'
+ *   UPDATE test SET col1 = 'newcol1', col2 = 'newcol2' WHERE tid = 1 AND (col1 <> 'newcol1' OR col2 <> 'newcol2')
  */
 class UpdateQuery_sqlite extends UpdateQuery {
-  /**
-   * Helper function that removes the fields that are already in a condition.
-   *
-   * @param $fields
-   *   The fields.
-   * @param QueryConditionInterface $condition
-   *   A database condition.
-   */
-  protected function removeFieldsInCondition(&$fields, QueryConditionInterface $condition) {
-    foreach ($condition->conditions() as $child_condition) {
-      if ($child_condition['field'] instanceof QueryConditionInterface) {
-        $this->removeFieldsInCondition($fields, $child_condition['field']);
-      }
-      else {
-        unset($fields[$child_condition['field']]);
-      }
-    }
-  }
-
   public function execute() {
     if (!empty($this->queryOptions['sqlite_return_matched_rows'])) {
       return parent::execute();
     }
 
-    // Get the fields used in the update query, and remove those that are already
-    // in the condition.
+    // Get the fields used in the update query.
     $fields = $this->expressionFields + $this->fields;
-    $this->removeFieldsInCondition($fields, $this->condition);
 
     // Add the inverse of the fields to the condition.
     $condition = new DatabaseCondition('OR');
diff --git a/modules/simpletest/tests/database_test.test b/modules/simpletest/tests/database_test.test
index 6e1d159..195637f 100644
--- a/modules/simpletest/tests/database_test.test
+++ b/modules/simpletest/tests/database_test.test
@@ -809,6 +809,20 @@ class DatabaseUpdateTestCase extends DatabaseTestCase {
       ->execute();
     $this->assertIdentical($num_rows, 3, t('Number of affected rows are returned.'));
   }
+
+  /**
+   * Confirm that we can update the primary key of a record successfully.
+   */
+  function testPrimaryKeyUpdate() {
+    $num_updated = db_update('test')
+      ->fields(array('id' => 42, 'name' => 'John'))
+      ->condition('id', 1)
+      ->execute();
+    $this->assertIdentical($num_updated, 1, t('Updated 1 record.'));
+
+    $saved_name= db_query('SELECT name FROM {test} WHERE id = :id', array(':id' => 42))->fetchField();
+    $this->assertIdentical($saved_name, 'John', t('Updated primary key successfully.'));
+  }
 }
 
 /**