diff -u b/core/modules/link/src/Plugin/migrate/field/d6/LinkField.php /dev/null
--- b/core/modules/link/src/Plugin/migrate/field/d6/LinkField.php
+++ /dev/null
@@ -1,48 +0,0 @@
-<?php
-
-namespace Drupal\link\Plugin\migrate\field\d6;
-
-use Drupal\migrate\Plugin\MigrationInterface;
-use Drupal\migrate_drupal\Plugin\migrate\field\FieldPluginBase;
-
-/**
- * @MigrateField(
- *   id = "link",
- *   core = {6},
- *   type_map = {
- *     "link_field" = "link"
- *   }
- * )
- */
-class LinkField extends FieldPluginBase {
-
-  /**
-   * {@inheritdoc}
-   */
-  public function getFieldFormatterMap() {
-    // See d6_field_formatter_settings.yml and FieldPluginBase
-    // processFieldFormatter().
-    return [
-      'default' => 'link',
-      'plain' => 'link',
-      'absolute' => 'link',
-      'title_plain' => 'link',
-      'url' => 'link',
-      'short' => 'link',
-      'label' => 'link',
-      'separate' => 'link_separate',
-    ];
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function processFieldValues(MigrationInterface $migration, $field_name, $data) {
-    $process = [
-      'plugin' => 'd6_field_link',
-      'source' => $field_name,
-    ];
-    $migration->mergeProcessOfProperty($field_name, $process);
-  }
-
-}
diff -u b/core/modules/link/src/Plugin/migrate/field/d7/LinkField.php b/core/modules/link/src/Plugin/migrate/field/d7/LinkField.php
--- b/core/modules/link/src/Plugin/migrate/field/d7/LinkField.php
+++ b/core/modules/link/src/Plugin/migrate/field/d7/LinkField.php
@@ -12,0 +13,48 @@
+ *     "link_field" = "link"
+ *   }
+ * )
+ *
+ * This plugin provides the exact same functionality as the Drupal 6 "link"
+ * plugin with the exception that the plugin ID "link_field" is used in the
+ * field type map.
+ */
+class LinkField extends D6LinkField {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getFieldWidgetMap() {
+    // By default, use the plugin ID for the widget types.
+    return ['link_field' => 'link_default'];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function processFieldInstance(MigrationInterface $migration) {
+    $process = [
+      'plugin' => 'static_map',
+      'source' => 'instance_settings/title',
+      'bypass' => TRUE,
+      'map' => [
+        'disabled' => DRUPAL_DISABLED,
+        'optional' => DRUPAL_OPTIONAL,
+        'required' => DRUPAL_REQUIRED,
+      ],
+    ];
+    $migration->mergeProcessOfProperty('settings/title', $process);
+  }
+
+}
+<?php
+
+namespace Drupal\link\Plugin\migrate\cckfield\d7;
+
+use Drupal\link\Plugin\migrate\cckfield\LinkField as D6LinkField;
+use Drupal\migrate\Plugin\MigrationInterface;
+
+/**
+ * @MigrateCckField(
+ *   id = "link_field",
+ *   core = {7},
+ *   type_map = {
diff -u b/core/modules/link/tests/src/Unit/Plugin/migrate/process/d6/FieldLinkTest.php /dev/null
--- b/core/modules/link/tests/src/Unit/Plugin/migrate/process/d6/FieldLinkTest.php
+++ /dev/null
@@ -1,56 +0,0 @@
-<?php
-
-namespace Drupal\Tests\link\Unit\Plugin\migrate\process\d6;
-
-use Drupal\link\Plugin\migrate\process\d6\FieldLink;
-use Drupal\Tests\UnitTestCase;
-
-/**
- * @group Link
- */
-class FieldLinkTest extends UnitTestCase {
-
-  /**
-   * Test the url transformations in the FieldLink process plugin.
-   *
-   * @dataProvider canonicalizeUriDataProvider
-   */
-  public function testCanonicalizeUri($url, $expected) {
-    $link_plugin = new FieldLink([], '', [], $this->getMock('\Drupal\migrate\Plugin\MigrationInterface'));
-    $transformed = $link_plugin->transform([
-      'url' => $url,
-      'title' => '',
-      'attributes' => serialize([]),
-    ], $this->getMock('\Drupal\migrate\MigrateExecutableInterface'), $this->getMockBuilder('\Drupal\migrate\Row')->disableOriginalConstructor()->getMock(), NULL);
-    $this->assertEquals($expected, $transformed['uri']);
-  }
-
-  /**
-   * Data provider for testCanonicalizeUri.
-   */
-  public function canonicalizeUriDataProvider() {
-    return [
-      'Simple front-page' => [
-        '<front>',
-        'internal:/',
-      ],
-      'Front page with query' => [
-        '<front>?query=1',
-        'internal:/?query=1',
-      ],
-      'No leading forward slash' => [
-        'node/10',
-        'internal:/node/10',
-      ],
-      'Leading forward slash' => [
-        '/node/10',
-        'internal:/node/10',
-      ],
-      'Existing scheme' => [
-        'scheme:test',
-        'scheme:test',
-      ],
-    ];
-  }
-
-}
diff -u b/core/modules/migrate_drupal/tests/src/Kernel/MigrateFieldPluginManagerTest.php b/core/modules/migrate_drupal/tests/src/Kernel/MigrateFieldPluginManagerTest.php
--- b/core/modules/migrate_drupal/tests/src/Kernel/MigrateFieldPluginManagerTest.php
+++ b/core/modules/migrate_drupal/tests/src/Kernel/MigrateFieldPluginManagerTest.php
@@ -12,10 +12,11 @@
  */
 class MigrateFieldPluginManagerTest extends MigrateDrupalTestBase {
 
+  public static $modules = ['system', 'user', 'field', 'migrate_drupal', 'options', 'file', 'text', 'migrate_field_plugin_manager_test'];
+  
   /**
    * {@inheritdoc}
    */
-  public static $modules = array('system', 'user', 'field', 'migrate_drupal', 'options', 'file', 'text', 'migrate_field_plugin_manager_test');
 
   /**
    * Tests that the correct MigrateField plugins are used.
only in patch2:
unchanged:
--- a/core/modules/link/src/Plugin/migrate/cckfield/d7/LinkField.php
+++ /dev/null
@@ -1,48 +0,0 @@
-<?php
-
-namespace Drupal\link\Plugin\migrate\cckfield\d7;
-
-use Drupal\link\Plugin\migrate\cckfield\LinkField as D6LinkField;
-use Drupal\migrate\Plugin\MigrationInterface;
-
-/**
- * @MigrateCckField(
- *   id = "link_field",
- *   core = {7},
- *   type_map = {
- *     "link_field" = "link"
- *   }
- * )
- *
- * This plugin provides the exact same functionality as the Drupal 6 "link"
- * plugin with the exception that the plugin ID "link_field" is used in the
- * field type map.
- */
-class LinkField extends D6LinkField {
-
-  /**
-   * {@inheritdoc}
-   */
-  public function getFieldWidgetMap() {
-    // By default, use the plugin ID for the widget types.
-    return ['link_field' => 'link_default'];
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function processFieldInstance(MigrationInterface $migration) {
-    $process = [
-      'plugin' => 'static_map',
-      'source' => 'instance_settings/title',
-      'bypass' => TRUE,
-      'map' => [
-        'disabled' => DRUPAL_DISABLED,
-        'optional' => DRUPAL_OPTIONAL,
-        'required' => DRUPAL_REQUIRED,
-      ],
-    ];
-    $migration->mergeProcessOfProperty('settings/title', $process);
-  }
-
-}
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/link/src/Plugin/migrate/field/d6/LinkField.php
@@ -0,0 +1,48 @@
+<?php
+
+namespace Drupal\link\Plugin\migrate\field\d6;
+
+use Drupal\migrate\Plugin\MigrationInterface;
+use Drupal\migrate_drupal\Plugin\migrate\field\FieldPluginBase;
+
+/**
+ * @MigrateField(
+ *   id = "link",
+ *   core = {6},
+ *   type_map = {
+ *     "link_field" = "link"
+ *   }
+ * )
+ */
+class LinkField extends FieldPluginBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getFieldFormatterMap() {
+    // See d6_field_formatter_settings.yml and FieldPluginBase
+    // processFieldFormatter().
+    return [
+      'default' => 'link',
+      'plain' => 'link',
+      'absolute' => 'link',
+      'title_plain' => 'link',
+      'url' => 'link',
+      'short' => 'link',
+      'label' => 'link',
+      'separate' => 'link_separate',
+    ];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function processFieldValues(MigrationInterface $migration, $field_name, $data) {
+    $process = [
+      'plugin' => 'd6_field_link',
+      'source' => $field_name,
+    ];
+    $migration->mergeProcessOfProperty($field_name, $process);
+  }
+
+}
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/link/tests/src/Unit/Plugin/migrate/process/d6/FieldLinkTest.php
@@ -0,0 +1,56 @@
+<?php
+
+namespace Drupal\Tests\link\Unit\Plugin\migrate\process\d6;
+
+use Drupal\link\Plugin\migrate\process\d6\FieldLink;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * @group Link
+ */
+class FieldLinkTest extends UnitTestCase {
+
+  /**
+   * Test the url transformations in the FieldLink process plugin.
+   *
+   * @dataProvider canonicalizeUriDataProvider
+   */
+  public function testCanonicalizeUri($url, $expected) {
+    $link_plugin = new FieldLink([], '', [], $this->getMock('\Drupal\migrate\Plugin\MigrationInterface'));
+    $transformed = $link_plugin->transform([
+      'url' => $url,
+      'title' => '',
+      'attributes' => serialize([]),
+    ], $this->getMock('\Drupal\migrate\MigrateExecutableInterface'), $this->getMockBuilder('\Drupal\migrate\Row')->disableOriginalConstructor()->getMock(), NULL);
+    $this->assertEquals($expected, $transformed['uri']);
+  }
+
+  /**
+   * Data provider for testCanonicalizeUri.
+   */
+  public function canonicalizeUriDataProvider() {
+    return [
+      'Simple front-page' => [
+        '<front>',
+        'internal:/',
+      ],
+      'Front page with query' => [
+        '<front>?query=1',
+        'internal:/?query=1',
+      ],
+      'No leading forward slash' => [
+        'node/10',
+        'internal:/node/10',
+      ],
+      'Leading forward slash' => [
+        '/node/10',
+        'internal:/node/10',
+      ],
+      'Existing scheme' => [
+        'scheme:test',
+        'scheme:test',
+      ],
+    ];
+  }
+
+}
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/migrate/tests/src/Unit/process/SkipRowIfNotSetTest.php
@@ -0,0 +1,45 @@
+<?php
+
+namespace Drupal\Tests\migrate\Unit\process;
+
+use Drupal\migrate\MigrateSkipRowException;
+use Drupal\migrate\Plugin\migrate\process\SkipRowIfNotSet;
+
+/**
+ * Tests the skip row if not set process plugin.
+ *
+ * @group migrate
+ * @coversDefaultClass \Drupal\migrate\Plugin\migrate\process\SkipRowIfNotSet
+ */
+class SkipRowIfNotSetTest extends MigrateProcessTestCase {
+
+  /**
+   * Tests that a skip row exception without a message is raised.
+   *
+   * @covers ::transform
+   */
+  public function testRowSkipWithoutMessage() {
+    $configuration = [
+      'index' => 'some_key',
+    ];
+    $process = new SkipRowIfNotSet($configuration, 'skip_row_if_not_set', []);
+    $this->setExpectedException(MigrateSkipRowException::class);
+    $process->transform('', $this->migrateExecutable, $this->row, 'destinationproperty');
+  }
+
+  /**
+   * Tests that a skip row exception with a message is raised.
+   *
+   * @covers ::transform
+   */
+  public function testRowSkipWithMessage() {
+    $configuration = [
+      'index' => 'some_key',
+      'message' => "The 'some_key' key is not set",
+    ];
+    $process = new SkipRowIfNotSet($configuration, 'skip_row_if_not_set', []);
+    $this->setExpectedException(MigrateSkipRowException::class, "The 'some_key' key is not set");
+    $process->transform('', $this->migrateExecutable, $this->row, 'destinationproperty');
+  }
+
+}