Issue #1901934 by damiankloip, dawehner, chx: Fixed Configuration entity query...

Issue #1901934 by damiankloip, dawehner, chx: Fixed Configuration entity query doesn't filter properly for NULL values.

core/lib/Drupal/Core/Config/Entity/Query/Condition.php

@@ -9,6 +9,7 @@
 
 use Drupal\Core\Entity\Query\ConditionBase;
 use Drupal\Core\Entity\Query\ConditionInterface;
+use Drupal\Core\Entity\Query\QueryException;
 
 /**
  * Defines the condition class for the config entity query.
@@ -110,7 +111,11 @@ protected function matchArray(array $condition, array $data, array $needs_matchi
     if ($parent === '*') {
       $candidates = array_keys($data);
     }
-    elseif (isset($data[$parent])) {
+    else {
+      // Avoid a notice when calling match() later.
+      if (!isset($data[$parent])) {
+        $data[$parent] = NULL;
+      }
       $candidates = array($parent);
     }
     foreach ($candidates as $key) {
@@ -169,6 +174,10 @@ protected function match(array $condition, $value) {
           return substr($value, -strlen($condition['value'])) === (string) $condition['value'];
         case 'IS NOT NULL':
           return TRUE;
+        case 'IS NULL':
+          return FALSE;
+        default:
+          throw new QueryException('Invalid condition operator.');
       }
     }
     return $condition['operator'] === 'IS NULL';

core/modules/system/lib/Drupal/system/Tests/Entity/ConfigEntityQueryTest.php

@@ -321,6 +321,27 @@ public function testConfigEntityQuery() {
       ->condition($and_condition_2)
       ->execute();
     $this->assertResults(array('1', '2', '4', '5'));
+
+    // Test the exists and notExists conditions.
+    $this->queryResults = $this->factory->get('config_query_test')
+      ->exists('id')
+      ->execute();
+    $this->assertResults(array('1', '2', '3', '4', '5'));
+
+    $this->queryResults = $this->factory->get('config_query_test')
+      ->exists('non-existent')
+      ->execute();
+    $this->assertResults(array());
+
+    $this->queryResults = $this->factory->get('config_query_test')
+      ->notExists('id')
+      ->execute();
+    $this->assertResults(array());
+
+    $this->queryResults = $this->factory->get('config_query_test')
+      ->notExists('non-existent')
+      ->execute();
+    $this->assertResults(array('1', '2', '3', '4', '5'));
   }
 
   /**