Issue #6243: Cached node author name can be outdated.

By @indigoxela, @suriyan2538, @argiepiano, @izmeez, @klonos, and @stpaultim.

.cspell/backdrop.dic

@@ -468,6 +468,7 @@ timeentry
 timestep
 titleslogan
 Título
+tnid
 tnids
 todate
 tookit's

core/modules/node/node.module

@@ -1542,6 +1542,26 @@ function node_user_predelete($account) {
     ->execute();
 }
 
+/**
+ * Implements hook_user_update().
+ */
+function node_user_update($account) {
+  $orig = $account->original;
+  if ($account->name != $orig->name || $account->picture != $orig->picture || $account->data != $orig->data) {
+    $nids = db_select('node', 'n')
+      ->fields('n', array('nid'))
+      ->condition('uid', $account->uid)
+      ->execute()
+      ->fetchCol();
+
+    if (!empty($nids)) {
+      // Flush entity cache of nodes this user authored, to prevent outdated
+      // info (like old username) in cached data.
+      cache('entity_node')->deleteMultiple($nids);
+    }
+  }
+}
+
 /**
  * Access callback: Checks node revision access.
  *

core/modules/node/tests/node.test

@@ -3784,7 +3784,7 @@ class NodePageCacheTest extends NodeWebTestCase {
    * Make sure that creating a new node does not affect existing entity cache
    * records, and updating a node only acts on the affected cid.
    */
-  function testNodeUpdateInsertCache() {
+  protected function testNodeUpdateInsertCache() {
     $node_one = $this->backdropCreateNode(array('title' => 'Node one'));
     $node_two = $this->backdropCreateNode(array('title' => 'Node two'));
     $ids = array($node_one->nid, $node_two->nid);
@@ -3818,6 +3818,30 @@ class NodePageCacheTest extends NodeWebTestCase {
     $this->assertEqual(count($cached_after_insert), 3, 'All three nodes have a record in table cache_entity_node.');
     $this->assertEqual($cached_after_insert[1]->created, $cached[1]->created, 'Cache timestamp of node 1 is unchanged.');
   }
+
+  /**
+   * Check that cached node info does not run out of sync with user data.
+   */
+  protected function testNodeSaveAfterUsernameChange() {
+    $author = $this->backdropCreateUser(array('create page content'));
+    $node = $this->backdropCreateNode(array(
+      'uid' => $author->uid,
+      'name' => $author->name,
+    ));
+
+    // Trigger entity cache.
+    $this->backdropGet('node/' . $node->nid);
+
+    // Simulate a username change (without actual form interaction).
+    $author->name = 'new_name';
+    user_save($author);
+
+    // Freshly load data and compare.
+    $user = entity_load('user', $author->uid);
+    $node_after = entity_load('node', $node->nid);
+    $this->assertEqual($user->name, $node_after->name, 'Name property in loaded node is equal to username after change');
+  }
+
 }
 
 /**