Close #3588 Allow newly enabled module config to be overridden. (#3589)

modules/custom/az_core/src/Plugin/ConfigProvider/QuickstartConfigProvider.php

@@ -262,14 +262,20 @@ protected function canOverride($name) {
     $lister = \Drupal::service('config_update.config_list');
     /** @var \Drupal\config_update\ConfigDiffer $differ */
     $differ = \Drupal::service('config_update.config_diff');
-
     // Read active config value for name.
     $active = $this->getActiveStorages()->read($name);
     // Find out which module owns the configuration and load the snapshot value.
     $owner = $lister->getConfigProvider($name);
     if (!empty($owner[1])) {
       $snapshot_storage = $this->getConfigSnapshotStorage(ConfigSyncSnapshotterInterface::CONFIG_SNAPSHOT_SET, $owner[0], $owner[1]);
       $snap = $snapshot_storage->read($name);
+      // StorageInterface::read() returns FALSE if the config does not exist.
+      // In this case, we can assume that the configuration is not customized
+      // because it is not present in the snapshot, likely because the module
+      // is newly installed.
+      if ($snap === FALSE) {
+        return TRUE;
+      }
     }
     // Guard against missing items.
     $snap = (!empty($snap)) ? $snap : [];

modules/custom/az_core/tests/src/Functional/ConfigOverrideTest.php

@@ -51,4 +51,32 @@ public function testConfigOverride() {
     $this->assertEquals('shibboleth.arizona.edu', $hostname);
   }
 
+  /**
+   * Tests a config override was applied successfully after module install.
+   */
+  public function testConfigOverrideAfterInstall() {
+    // Install the az_mail module.
+    $this->container->get('module_installer')->install(['az_mail']);
+    $config = $this->config('smtp.settings');
+    $this->assertEquals(TRUE, $config->get('smtp_on'));
+    $this->assertEquals('email-smtp.us-west-2.amazonaws.com', $config->get('smtp_host'));
+    $this->assertEquals('', $config->get('smtp_hostbackup'));
+    $this->assertEquals('2587', $config->get('smtp_port'));
+    $this->assertEquals('tls', $config->get('smtp_protocol'));
+    $this->assertEquals(TRUE, $config->get('smtp_autotls'));
+    $this->assertEquals(30, $config->get('smtp_timeout'));
+    $this->assertEquals('', $config->get('smtp_username'));
+    $this->assertEquals('', $config->get('smtp_password'));
+    $this->assertEquals('', $config->get('smtp_from'));
+    $this->assertEquals('', $config->get('smtp_fromname'));
+    $this->assertEquals('', $config->get('smtp_client_hostname'));
+    $this->assertEquals('', $config->get('smtp_client_helo'));
+    $this->assertEquals('0', $config->get('smtp_allowhtml'));
+    $this->assertEquals('', $config->get('smtp_test_address'));
+    $this->assertEquals('', $config->get('smtp_reroute_address'));
+    $this->assertEquals(FALSE, $config->get('smtp_debugging'));
+    $this->assertEquals('php_mail', $config->get('prev_mail_system'));
+    $this->assertEquals(FALSE, $config->get('smtp_keepalive'));
+  }
+
 }