Issue #3187418 by Wim Leers, huzooka: System site translation shouldn't...

Issue #3187418 by Wim Leers, huzooka: System site translation shouldn't migrate properties which are not translatable

(cherry picked from commit c5eada74)

core/modules/config_translation/migrations/d7_system_site_translation.yml

@@ -8,19 +8,11 @@ source:
   plugin: d7_variable_translation
   variables:
     - site_name
-    - site_mail
     - site_slogan
-    - site_frontpage
-    - site_403
-    - site_404
 process:
   langcode: language
   name: site_name
-  mail: site_mail
   slogan: site_slogan
-  'page/front': site_frontpage
-  'page/403': site_403
-  'page/404': site_404
 destination:
   plugin: config
   config_name: system.site

core/modules/config_translation/tests/src/Kernel/Migrate/d7/MigrateSystemSiteTranslationTest.php

@@ -35,17 +35,17 @@ public function testSystemSite() {
     $config_translation = $language_manager->getLanguageConfigOverride('fr', 'system.site');
     $this->assertSame('The Site Name', $config_translation->get('name'));
     $this->assertSame('fr - The Slogan', $config_translation->get('slogan'));
-    $this->assertSame('node', $config_translation->get('page.403'));
-    $this->assertSame('node', $config_translation->get('page.404'));
-    $this->assertSame('node', $config_translation->get('page.front'));
+    $this->assertSame(NULL, $config_translation->get('page.403'));
+    $this->assertSame(NULL, $config_translation->get('page.404'));
+    $this->assertSame(NULL, $config_translation->get('page.front'));
     $this->assertSame(NULL, $config_translation->get('admin_compact_mode'));
 
     $config_translation = $language_manager->getLanguageConfigOverride('is', 'system.site');
     $this->assertSame('is - The Site Name', $config_translation->get('name'));
     $this->assertSame('is - The Slogan', $config_translation->get('slogan'));
-    $this->assertSame('node/1', $config_translation->get('page.403'));
-    $this->assertSame('node/6', $config_translation->get('page.404'));
-    $this->assertSame('node/4', $config_translation->get('page.front'));
+    $this->assertSame(NULL, $config_translation->get('page.403'));
+    $this->assertSame(NULL, $config_translation->get('page.404'));
+    $this->assertSame(NULL, $config_translation->get('page.front'));
     $this->assertNULL($config_translation->get('admin_compact_mode'));
   }