reverted:
--- b/core/modules/migrate_drupal_ui/src/Tests/d7/MigrateUpgrade7Test.php
+++ a/core/modules/migrate_drupal_ui/src/Tests/d7/MigrateUpgrade7Test.php
@@ -50,7 +50,7 @@
       'image_style' => 6,
       'language_content_settings' => 2,
       'migration' => 73,
+      'node' => 3,
-      'node' => 2,
       'node_type' => 6,
       'rdf_mapping' => 5,
       'search_page' => 2,
diff -u b/core/modules/node/migration_templates/d7_node_translation.yml b/core/modules/node/migration_templates/d7_node.yml
--- b/core/modules/node/migration_templates/d7_node_translation.yml
+++ b/core/modules/node/migration_templates/d7_node.yml
@@ -1,16 +1,18 @@
-id: d7_node_translation
-label: Node translations
+id: d7_node
+label: Nodes
 migration_tags:
   - Drupal 7
 deriver: Drupal\node\Plugin\migrate\D7NodeDeriver
 source:
   plugin: d7_node
-  translations: true
 process:
   # If you are using this file to build a custom migration consider removing
   # the nid and vid fields to allow incremental migrations.
+  # In D7, nodes always have a tnid, but it's zero for untranslated nodes.
+  # We normalize it to equal the nid in that case.
+  # @see \Drupal\node\Plugin\migrate\source\d7\Node::prepareRow().
   nid: tnid
-  type: type
+  vid: vid
   langcode:
     plugin: default_value
     source: language
@@ -30,11 +32,6 @@
-  translations: true
-  content_translation_update_definitions:
-    - node
 migration_dependencies:
   required:
     - d7_user
     - d7_node_type
-    - language
   optional:
     - d7_field_instance
-provider: migrate_drupal
diff -u b/core/modules/node/src/Plugin/migrate/source/d7/Node.php b/core/modules/node/src/Plugin/migrate/source/d7/Node.php
--- b/core/modules/node/src/Plugin/migrate/source/d7/Node.php
+++ b/core/modules/node/src/Plugin/migrate/source/d7/Node.php
@@ -5,6 +5,11 @@
 use Drupal\migrate\Row;
 use Drupal\migrate_drupal\Plugin\migrate\source\d7\FieldableEntity;
 use Drupal\Core\Database\Query\SelectInterface;
+use Drupal\Core\Entity\EntityManagerInterface;
+use Drupal\Core\Extension\ModuleHandler;
+use Drupal\Core\State\StateInterface;
+use Drupal\migrate\Plugin\MigrationInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
  * Drupal 7 node source from database.
@@ -15,8 +20,36 @@
  * )
  */
 class Node extends FieldableEntity {
+  /**
+   * The module handler.
+   *
+   * @var \Drupal\Core\Extension\ModuleHandler
+   */
+  protected $moduleHandler;
 
   /**
+   * {@inheritdoc}
+   */
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, MigrationInterface $migration, StateInterface $state, EntityManagerInterface $entity_manager, ModuleHandler $module_handler) {
+    parent::__construct($configuration, $plugin_id, $plugin_definition, $migration, $state, $entity_manager);
+    $this->moduleHandler = $module_handler;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition, MigrationInterface $migration = NULL) {
+    return new static(
+      $configuration,
+      $plugin_id,
+      $plugin_definition,
+      $migration,
+      $container->get('state'),
+      $container->get('entity.manager'),
+      $container->get('module_handler')
+    );
+  }
+  /**
    * The join options between the node and the node_revisions table.
    */
   const JOIN = 'n.vid = nr.vid';
@@ -50,6 +83,12 @@
     $query->addField('nr', 'uid', 'revision_uid');
     $query->innerJoin('node', 'n', static::JOIN);
 
+    // If the content_translation module is enabled, get the source langcode
+    // to fill the content_translation_source field.
+    if ($this->moduleHandler->moduleExists('content_translation')) {
+      $query->leftJoin('node', 'nt', 'n.tnid = nt.nid');
+      $query->addField('nt', 'language', 'source_langcode');
+    }
     $this->handleTranslations($query);
 
     if (isset($this->configuration['node_type'])) {
diff -u b/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeTest.php b/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeTest.php
--- b/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeTest.php
+++ b/core/modules/node/tests/src/Kernel/Migrate/d7/MigrateNodeTest.php
@@ -46,6 +46,7 @@
       'd7_user_role',
       'd7_user',
       'd7_node_type',
+      'd7_language_content_settings',
       'd7_comment_type',
       'd7_taxonomy_vocabulary',
       'd7_field',
@@ -161,8 +162,17 @@
     $this->assertSame('internal:/', $translation->field_link->uri);
     $this->assertSame('Home', $translation->field_link->title);
 
+    // Test that content_translation_source is set.
+    $manager = $this->container->get('content_translation.manager');
+    $this->assertSame('en', $manager->getTranslationMetadata($node->getTranslation('is'))->getSource());
+
     // Node 3 is a translation of node 2, and should not be imported separately.
     $this->assertNull(Node::load(3), "Node 3 doesn't exist in D8, it was a translation");
+
+    // Test that content_translation_source for a source other than English.
+    $node = Node::load(4);
+    $this->assertSame('is', $manager->getTranslationMetadata($node->getTranslation('en'))->getSource());
+
   }
 
 }
only in patch2:
unchanged:
--- a/core/modules/migrate_drupal/tests/fixtures/drupal7.php
+++ b/core/modules/migrate_drupal/tests/fixtures/drupal7.php
@@ -5697,6 +5697,30 @@
   'body_summary' => '',
   'body_format' => 'filtered_html',
 ))
+->values(array(
+  'entity_type' => 'node',
+  'bundle' => 'article',
+  'deleted' => '0',
+  'entity_id' => '4',
+  'revision_id' => '4',
+  'language' => 'und',
+  'delta' => '0',
+  'body_value' => 'is - Is that is it awesome.',
+  'body_summary' => '',
+  'body_format' => 'filtered_html',
+))
+->values(array(
+  'entity_type' => 'node',
+  'bundle' => 'article',
+  'deleted' => '0',
+  'entity_id' => '5',
+  'revision_id' => '5',
+  'language' => 'und',
+  'delta' => '0',
+  'body_value' => 'en - Is that is it awesome.',
+  'body_summary' => '',
+  'body_format' => 'filtered_html',
+))
 ->execute();
 
 $connection->schema()->createTable('field_revision_comment_body', array(
@@ -8086,6 +8110,24 @@
   'mysql_character_set' => 'utf8',
 ));
 
+$connection->insert('history')
+->fields(array(
+  'uid',
+  'nid',
+  'timestamp',
+))
+->values(array(
+  'uid' => '1',
+  'nid' => '4',
+  'timestamp' => '1478755275',
+))
+->values(array(
+  'uid' => '1',
+  'nid' => '5',
+  'timestamp' => '1478755314',
+))
+->execute();
+
 $connection->schema()->createTable('image_effects', array(
   'fields' => array(
     'ieid' => array(
@@ -8777,6 +8819,22 @@
   'context' => '',
   'version' => 'none',
 ))
+->values(array(
+  'lid' => '49',
+  'location' => 'misc/ajax.js',
+  'textgroup' => 'default',
+  'source' => 'The response failed verification so will not be processed.',
+  'context' => '',
+  'version' => 'none',
+))
+->values(array(
+  'lid' => '50',
+  'location' => 'misc/ajax.js',
+  'textgroup' => 'default',
+  'source' => 'The callback URL is not local and not trusted: !url',
+  'context' => '',
+  'version' => 'none',
+))
 ->execute();
 
 $connection->schema()->createTable('locales_target', array(
@@ -29893,6 +29951,38 @@
   'tnid' => '2',
   'translate' => '0',
 ))
+->values(array(
+  'nid' => '4',
+  'vid' => '4',
+  'type' => 'article',
+  'language' => 'is',
+  'title' => 'is - The thing about Firefly',
+  'uid' => '1',
+  'status' => '1',
+  'created' => '1478755274',
+  'changed' => '1478755274',
+  'comment' => '2',
+  'promote' => '1',
+  'sticky' => '0',
+  'tnid' => '4',
+  'translate' => '0',
+))
+->values(array(
+  'nid' => '5',
+  'vid' => '5',
+  'type' => 'article',
+  'language' => 'en',
+  'title' => 'en - The thing about Firefly',
+  'uid' => '1',
+  'status' => '1',
+  'created' => '1478755314',
+  'changed' => '1478755314',
+  'comment' => '2',
+  'promote' => '1',
+  'sticky' => '0',
+  'tnid' => '4',
+  'translate' => '0',
+))
 ->execute();
 
 $connection->schema()->createTable('node_access', array(
@@ -30037,6 +30127,22 @@
   'last_comment_uid' => '1',
   'comment_count' => '0',
 ))
+->values(array(
+  'nid' => '4',
+  'cid' => '0',
+  'last_comment_timestamp' => '1478755274',
+  'last_comment_name' => NULL,
+  'last_comment_uid' => '1',
+  'comment_count' => '0',
+))
+->values(array(
+  'nid' => '5',
+  'cid' => '0',
+  'last_comment_timestamp' => '1478755314',
+  'last_comment_name' => NULL,
+  'last_comment_uid' => '1',
+  'comment_count' => '0',
+))
 ->execute();
 
 $connection->schema()->createTable('node_counter', array(
@@ -30091,15 +30197,27 @@
 ->values(array(
   'nid' => '2',
   'totalcount' => '1',
-  'daycount' => '1',
+  'daycount' => '0',
   'timestamp' => '1471428059',
 ))
 ->values(array(
   'nid' => '3',
   'totalcount' => '1',
-  'daycount' => '1',
+  'daycount' => '0',
   'timestamp' => '1471428153',
 ))
+->values(array(
+  'nid' => '4',
+  'totalcount' => '1',
+  'daycount' => '1',
+  'timestamp' => '1478755275',
+))
+->values(array(
+  'nid' => '5',
+  'totalcount' => '1',
+  'daycount' => '1',
+  'timestamp' => '1478755314',
+))
 ->execute();
 
 $connection->schema()->createTable('node_revision', array(
@@ -30220,6 +30338,30 @@
   'promote' => '1',
   'sticky' => '0',
 ))
+->values(array(
+  'nid' => '4',
+  'vid' => '4',
+  'uid' => '1',
+  'title' => 'is - The thing about Firefly',
+  'log' => '',
+  'timestamp' => '1478755274',
+  'status' => '1',
+  'comment' => '2',
+  'promote' => '1',
+  'sticky' => '0',
+))
+->values(array(
+  'nid' => '5',
+  'vid' => '5',
+  'uid' => '1',
+  'title' => 'en - The thing about Firefly',
+  'log' => '',
+  'timestamp' => '1478755314',
+  'status' => '1',
+  'comment' => '2',
+  'promote' => '1',
+  'sticky' => '0',
+))
 ->execute();
 
 $connection->schema()->createTable('node_type', array(
@@ -40812,6 +40954,16 @@
   'published' => '1',
   'changed' => '1421727536',
 ))
+->values(array(
+  'nid' => '4',
+  'published' => '1',
+  'changed' => '1478755274',
+))
+->values(array(
+  'nid' => '5',
+  'published' => '1',
+  'changed' => '1478755314',
+))
 ->execute();
 
 $connection->schema()->createTable('tracker_user', array(