Don't wipe preloaded query results when setting the 'with' param

Fixes #1576

CHANGELOG-v3.md

@@ -11,6 +11,7 @@
 - `craft\base\Plugin` now sets the default `$controllerNamespace` value to the plugin class’ namespace + `\controllers` or `\console\controllers`, depending on whether it’s a web or console request.
 - Improved the contrast of success and error notices in the Control Panel to meet WCAG AA requirements. ([#2885](https://github.com/craftcms/cms/issues/2885))
 - `fieldValue` is now a protected field handle. ([#2893](https://github.com/craftcms/cms/issues/2893))
+- Craft will no longer discard any preloaded elements when setting the `with` param on an element query, fixing a bug where disabled Matrix blocks could show up in Live Preview if any nested fields were getting eager-loaded. ([#1576](https://github.com/craftcms/cms/issues/1576))
 
 ### Fixed
 - Fixed a bug where the Plugin Store was listing featured plugins (e.g. “Recently Added”) in alphabetical order rather than the API-defined order. ([pixelandtonic/craftnet#83](https://github.com/pixelandtonic/craftnet/issues/83))

src/elements/db/ElementQuery.php

@@ -20,6 +20,7 @@
 use craft\errors\SiteNotFoundException;
 use craft\events\CancelableEvent;
 use craft\events\PopulateElementEvent;
+use craft\helpers\ArrayHelper;
 use craft\helpers\Db;
 use craft\helpers\ElementHelper;
 use craft\helpers\StringHelper;
@@ -1042,6 +1043,9 @@ public function all($db = null)
  {
  // Cached?
  if (($cachedResult = $this->getCachedResult()) !== null) {
+ if ($this->with) {
+ Craft::$app->getElements()->eagerLoadElements($this->elementType, $cachedResult, $this->with);
+ }
  return $cachedResult;
  }
 
@@ -1114,7 +1118,6 @@ public function getCachedResult()
  // Make sure the criteria hasn't changed
  if ($this->_resultCriteria !== $this->getCriteria()) {
  $this->_result = null;
-
  return null;
  }
 
@@ -1142,7 +1145,12 @@ public function setCachedResult(array $elements)
  */
  public function getCriteria(): array
  {
- return $this->toArray($this->criteriaAttributes(), [], false);
+ $attributes = $this->criteriaAttributes();
+
+ // Ignore the 'with' param
+ ArrayHelper::removeValue($attributes, 'with');
+
+ return $this->toArray($attributes, [], false);
  }
 
  /**