Issue #3187463 by quietone, huzooka: Fix "d7_field_option_translation" process plugin

(cherry picked from commit 56d965c136cec6e332f3a60211e2dd57d7323994)

core/modules/field/src/Plugin/migrate/process/d7/FieldOptionTranslation.php

@@ -25,7 +25,7 @@ public function transform($value, MigrateExecutableInterface $migrate_executable
     list($type, $data) = $value;
 
     $data = unserialize($data);
-    $allowed_values = '';
+    $new_allowed_values = '';
     $translation_key = $row->getSourceProperty('property');
     if (isset($data['settings']['allowed_values'])) {
       $allowed_values = $data['settings']['allowed_values'];
@@ -35,7 +35,8 @@ public function transform($value, MigrateExecutableInterface $migrate_executable
         case 'list_float':
         case 'list_text':
           if (isset($allowed_values[$translation_key])) {
-            $allowed_values = ['label' => $row->getSourceProperty('translation')];
+            $new_allowed_values = ['label' => $row->getSourceProperty('translation')];
+            $translation_key = array_search($translation_key, array_keys($allowed_values));
             break;
           }
           break;
@@ -43,7 +44,7 @@ public function transform($value, MigrateExecutableInterface $migrate_executable
         default:
       }
     }
-    return ["settings.allowed_values.$translation_key", $allowed_values];
+    return ["settings.allowed_values.$translation_key", $new_allowed_values];
   }
 
 }

core/modules/field/tests/src/Kernel/Migrate/d7/MigrateFieldOptionTranslationTest.php

@@ -80,13 +80,13 @@ public function testFieldOptionTranslation() {
 
     $config_translation = $language_manager->getLanguageConfigOverride('fr', 'field.storage.node.field_rating');
     $allowed_values = [
-      1 => [
+      0 => [
         'label' => 'Haute',
       ],
-      2 => [
+      1 => [
         'label' => 'Moyenne',
       ],
-      3 => [
+      2 => [
         'label' => 'Faible',
       ],
     ];
@@ -94,13 +94,13 @@ public function testFieldOptionTranslation() {
 
     $config_translation = $language_manager->getLanguageConfigOverride('is', 'field.storage.node.field_rating');
     $allowed_values = [
-      1 => [
+      0 => [
         'label' => 'Hár',
       ],
-      2 => [
+      1 => [
         'label' => 'Miðlungs',
       ],
-      3 => [
+      2 => [
         'label' => 'Lágt',
       ],
     ];