CacheableMetadata should get BubbleableMetadata's merge/applyTo/createFromRenderArray/createFromObject methods

Reviewing #2099137: Entity/field access and node grants not taken into account with core cache contexts: That issue uses BubbleableMetadata needlessly when this patch goes in.

Should we convert usages of BubbleableMetadata that should have been CacheableMetadata here or in a follow-up?

RTBC, the remaining usages of BubbleableMetadata want to deal with #post_render_cache or #attached ...

This blocks a critical. Committed 149c25e and pushed to 8.0.x. Thanks!

Thanks for adding the beta evaluation to the issue summary.

diff --git a/core/lib/Drupal/Core/Render/BubbleableMetadata.php b/core/lib/Drupal/Core/Render/BubbleableMetadata.php
index b231d0f..bed247a 100644
--- a/core/lib/Drupal/Core/Render/BubbleableMetadata.php
+++ b/core/lib/Drupal/Core/Render/BubbleableMetadata.php
@@ -8,8 +8,6 @@
 namespace Drupal\Core\Render;
 
 use Drupal\Component\Utility\NestedArray;
-use Drupal\Core\Cache\Cache;
-use Drupal\Core\Cache\CacheableDependencyInterface;
 use Drupal\Core\Cache\CacheableMetadata;
 
 /**
@@ -36,8 +34,9 @@ class BubbleableMetadata extends CacheableMetadata {
   /**
    * Merges the values of another bubbleable metadata object with this one.
    *
-   * @param \Drupal\Core\Render\CacheableMetadata $other
+   * @param \Drupal\Core\Cache\CacheableMetadata $other
    *   The other bubbleable metadata object.
+   *
    * @return static
    *   A new bubbleable metadata object, with the merged data.
    *

Fixed on commit.

I think its worth doing a quick follow-up for that normal bug to add the instanceof so we don't forget independently of the other issue ...

#2099137: Entity/field access and node grants not taken into account with core cache contexts had \Drupal\views\Plugin\views\field\Field::getItems() merge BubblebleMetadata from the formatter's render array wrapper (which Views doesn't render) into each of the children (which are the ones that get rendered)

This patch here changed that to merging CacheableMetadata instead, leaving out #attached. Meaning, formatters who include assets are broken in Views, unless they repeatedly #attach them to each item children.

I posted a patch in #2496039: Formatter's #attached assets are not carried over by Views before realizing this had been explicitly changed here, so feedback welcome :-)