Update to Drupal 8.2.6. For more information, see https://www.drupal.org/project/drupal/releases/8.2.6

core/modules/path/migration_templates/d6_url_alias.yml

@@ -20,5 +20,17 @@ process:
   langcode:
     plugin: d6_url_alias_language
     source: language
+  node_translation:
+    -
+      plugin: explode
+      source: src
+      delimiter: /
+    -
+      plugin: extract
+      index:
+        - 1
+    -
+      plugin: migration
+      migration: d6_node_translation
 destination:
   plugin: url_alias

core/modules/path/src/Plugin/migrate/destination/UrlAlias.php

@@ -59,13 +59,21 @@ class UrlAlias extends DestinationBase implements ContainerFactoryPluginInterfac
    * {@inheritdoc}
    */
   public function import(Row $row, array $old_destination_id_values = array()) {
+    $source = $row->getDestinationProperty('source');
+    $alias = $row->getDestinationProperty('alias');
+    $langcode = $row->getDestinationProperty('langcode');
+    $pid = $old_destination_id_values ? $old_destination_id_values[0] : NULL;
 
-    $path = $this->aliasStorage->save(
-      $row->getDestinationProperty('source'),
-      $row->getDestinationProperty('alias'),
-      $row->getDestinationProperty('langcode'),
-      $old_destination_id_values ? $old_destination_id_values[0] : NULL
-    );
+    // Check if this alias is for a node and if that node is a translation.
+    if (preg_match('/^\/node\/\d+$/', $source) && $row->hasDestinationProperty('node_translation')) {
+
+      // Replace the alias source with the translation source path.
+      $node_translation = $row->getDestinationProperty('node_translation');
+      $source = '/node/' . $node_translation[0];
+      $langcode = $node_translation[1];
+    }
+
+    $path = $this->aliasStorage->save($source, $alias, $langcode, $pid);
 
     return array($path['pid']);
   }

core/modules/path/src/Plugin/migrate/source/UrlAliasBase.php

@@ -13,7 +13,11 @@ abstract class UrlAliasBase extends DrupalSqlBase {
    * {@inheritdoc}
    */
   public function query() {
-    return $this->select('url_alias', 'ua')->fields('ua');
+    // The order of the migration is significant since
+    // \Drupal\Core\Path\AliasStorage::lookupPathAlias() orders by pid before
+    // returning a result. Postgres does not automatically order by primary key
+    // therefore we need to add a specific order by.
+    return $this->select('url_alias', 'ua')->fields('ua')->orderBy('pid');
   }
 
   /**

core/modules/path/tests/src/Kernel/Migrate/d6/MigrateUrlAliasTest.php

@@ -16,14 +16,26 @@ class MigrateUrlAliasTest extends MigrateDrupal6TestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = array('path');
+  public static $modules = ['language', 'content_translation', 'path'];
 
   /**
    * {@inheritdoc}
    */
   protected function setUp() {
     parent::setUp();
-    $this->executeMigration('d6_url_alias');
+    $this->installEntitySchema('node');
+    $this->installConfig(['node']);
+    $this->installSchema('node', ['node_access']);
+    $this->migrateUsers(FALSE);
+    $this->migrateFields();
+
+    $this->executeMigrations([
+      'language',
+      'd6_node_settings',
+      'd6_node',
+      'd6_node_translation',
+      'd6_url_alias',
+    ]);
   }
 
   /**
@@ -93,4 +105,33 @@ class MigrateUrlAliasTest extends MigrateDrupal6TestBase {
     $this->assertPath('3', $conditions, $path);
   }
 
+  /**
+   * Test the URL alias migration with translated nodes.
+   */
+  public function testUrlAliasWithTranslatedNodes() {
+    $alias_storage = $this->container->get('path.alias_storage');
+
+    // Alias for the 'The Real McCoy' node in English.
+    $path = $alias_storage->load(['alias' => '/the-real-mccoy']);
+    $this->assertSame('/node/10', $path['source']);
+    $this->assertSame('en', $path['langcode']);
+
+    // Alias for the 'The Real McCoy' French translation,
+    // which should now point to node/10 instead of node/11.
+    $path = $alias_storage->load(['alias' => '/le-vrai-mccoy']);
+    $this->assertSame('/node/10', $path['source']);
+    $this->assertSame('fr', $path['langcode']);
+
+    // Alias for the 'Abantu zulu' node in Zulu.
+    $path = $alias_storage->load(['alias' => '/abantu-zulu']);
+    $this->assertSame('/node/12', $path['source']);
+    $this->assertSame('zu', $path['langcode']);
+
+    // Alias for the 'Abantu zulu' English translation,
+    // which should now point to node/12 instead of node/13.
+    $path = $alias_storage->load(['alias' => '/the-zulu-people']);
+    $this->assertSame('/node/12', $path['source']);
+    $this->assertSame('en', $path['langcode']);
+  }
+
 }