Issue #2598232 by Berdir, alexpott, juanse254: ConfigFactory::get() pollutes...

Issue #2598232 by Berdir, alexpott, juanse254: ConfigFactory::get() pollutes ::loadMultiple() static cache with new config objects

core/lib/Drupal/Core/Config/ConfigFactory.php

@@ -111,25 +111,26 @@ protected function doGet($name, $immutable = TRUE) {
     }
     else {
       // If the configuration object does not exist in the configuration
-      // storage, create a new object and add it to the static cache.
-      $cache_key = $this->getConfigCacheKey($name, $immutable);
-      $this->cache[$cache_key] = $this->createConfigObject($name, $immutable);
+      // storage, create a new object.
+      $config = $this->createConfigObject($name, $immutable);
 
       if ($immutable) {
         // Get and apply any overrides.
         $overrides = $this->loadOverrides(array($name));
         if (isset($overrides[$name])) {
-          $this->cache[$cache_key]->setModuleOverride($overrides[$name]);
+          $config->setModuleOverride($overrides[$name]);
         }
         // Apply any settings.php overrides.
         if (isset($GLOBALS['config'][$name])) {
-          $this->cache[$cache_key]->setSettingsOverride($GLOBALS['config'][$name]);
+          $config->setSettingsOverride($GLOBALS['config'][$name]);
         }
       }
 
-      $this->propagateConfigOverrideCacheability($cache_key, $name);
+      foreach ($this->configFactoryOverrides as $override) {
+        $config->addCacheableDependency($override->getCacheableMetadata($name));
+      }
 
-      return $this->cache[$cache_key];
+      return $config;
     }
   }
 

core/modules/config/src/Tests/ConfigCRUDTest.php

@@ -150,6 +150,12 @@ function testCRUD() {
     $new_config->save();
     $this->assertIdentical($new_config->get('value'), $expected_values['value']);
     $this->assertIdentical($new_config->get('404'), $expected_values['404']);
+
+    // Test that getMultiple() does not return new config objects that were
+    // previously accessed with get()
+    $new_config = $config_factory->get('non_existing_key');
+    $this->assertTrue($new_config->isNew());
+    $this->assertEqual(0, count($config_factory->loadMultiple(['non_existing_key'])), 'loadMultiple() does not return new objects');
   }
 
   /**

core/modules/config/src/Tests/ConfigOverrideTest.php

@@ -132,6 +132,8 @@ function testConfOverride() {
       ->save();
     // Ensure override is preserved but all other data has been updated
     // accordingly.
+    $config = \Drupal::config('config_test.new');
+    $this->assertFalse($config->isNew(), 'The configuration object config_test.new is not new');
     $this->assertIdentical($config->get('key'), 'override');
     $this->assertIdentical($config->get('new_key'), 'new_value');
     $raw_data = $config->getRawData();