diff --git a/core/modules/action/tests/action_loop_test/action_loop_test.module b/core/modules/action/tests/action_loop_test/action_loop_test.module
index 1a4de40..97dd8d9 100644
--- a/core/modules/action/tests/action_loop_test/action_loop_test.module
+++ b/core/modules/action/tests/action_loop_test/action_loop_test.module
@@ -21,6 +21,9 @@ function action_loop_test_watchdog(array $log_entry) {
 
 /**
  * Implements hook_custom_theme().
+ *
+ * We need to check wheter a loop should be triggered and we do this as early
+ * possible, in the first hook that fires.
  */
 function action_loop_test_custom_theme() {
   if (!empty($_GET['trigger_action_on_watchdog'])) {
diff --git a/core/modules/overlay/lib/Drupal/overlay/EventSubscriber/OverlaySubscriber.php b/core/modules/overlay/lib/Drupal/overlay/EventSubscriber/OverlaySubscriber.php
index 320aa52..f8e0aea 100644
--- a/core/modules/overlay/lib/Drupal/overlay/EventSubscriber/OverlaySubscriber.php
+++ b/core/modules/overlay/lib/Drupal/overlay/EventSubscriber/OverlaySubscriber.php
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Contains Drupal\overlay\EventSubscriber\OverlaySubscriber.
+ * Contains \Drupal\overlay\EventSubscriber\OverlaySubscriber.
  */
 
 namespace Drupal\overlay\EventSubscriber;
diff --git a/core/modules/overlay/overlay.module b/core/modules/overlay/overlay.module
index 5d52b36..d34f175 100644
--- a/core/modules/overlay/overlay.module
+++ b/core/modules/overlay/overlay.module
@@ -549,10 +549,10 @@ function overlay_get_mode() {
  *   - 'none': This is used to avoid adding any overlay-related code to the
  *     page at all. Modules can set this to explicitly prevent the overlay from
  *     being used. For example, since the overlay module itself sets the mode
- *     to 'parent' or 'child' in overlay_init() when certain conditions are
- *     met, other modules which want to override that behavior can do so by
- *     setting the mode to 'none' earlier in the page request - e.g., in their
- *     own hook_page_build() implementations, if they have a lower weight.
+ *     to 'parent' or 'child' in the overlay event subscriber when certain
+ *     conditions are met, other modules which want to override that behavior
+ *     can do so by setting the mode to 'none' earlier in the page request -
+ *     e.g., in their own event subscribers, if they have a higher priority.
  *   This parameter is optional, and if omitted, the current mode will be
  *   returned with no action taken.
  *
@@ -560,7 +560,7 @@ function overlay_get_mode() {
  *   The current mode, if any has been set, or NULL if no mode has been set.
  *
  * @ingroup overlay_api
- * @see overlay_init()
+ * @see \Drupal\overlay\EventSubscriber\OverlaySubscriber::onRequest()
  */
 function overlay_set_mode($mode = NULL) {
   global $base_path;

diff --git a/core/update.php b/core/update.php
index b8992ad..1ced56b 100644
--- a/core/update.php
+++ b/core/update.php
@@ -33,8 +33,8 @@
 /**
  * Global flag indicating that update.php is being run.
  *
- * When this flag is set, various operations do not take place, such as  css/js
- * preprocessing, and translation.
+ * When this flag is set, various operations do not take place, such as css/js
+ * preprocessing and translation.
  *
  * This constant is defined using define() instead of const so that PHP
  * versions older than 5.3 can display the proper PHP requirements instead of