reverted:
--- b/core/modules/block/src/Plugin/migrate/source/d6/Block.php
+++ a/core/modules/block/src/Plugin/migrate/source/d6/Block.php
@@ -75,7 +75,6 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     $row->setSourceProperty('default_theme', $this->defaultTheme);
     $row->setSourceProperty('admin_theme', $this->adminTheme);
     $module = $row->getSourceProperty('module');
@@ -125,6 +124,7 @@
         break;
     }
     $row->setSourceProperty('settings', $settings);
+    return parent::prepareRow($row);
   }
   /**
    * {@inheritdoc}
reverted:
--- b/core/modules/comment/src/Plugin/migrate/source/d6/Comment.php
+++ a/core/modules/comment/src/Plugin/migrate/source/d6/Comment.php
@@ -38,7 +38,6 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     if ($this->variableGet('comment_subject_field_' . $row->getSourceProperty('type'), 1)) {
       // Comment subject visible.
       $row->setSourceProperty('field_name', 'comment');
@@ -51,6 +50,7 @@
     // In D6, status=0 means published, while in D8 means the opposite.
     // See https://www.drupal.org/node/237636.
     $row->setSourceProperty('status', !$row->getSourceProperty('status'));
+    return parent::prepareRow($row);
   }
 
   /**
diff -u b/core/modules/contact/src/Plugin/migrate/source/d6/ContactCategory.php b/core/modules/contact/src/Plugin/migrate/source/d6/ContactCategory.php
--- b/core/modules/contact/src/Plugin/migrate/source/d6/ContactCategory.php
+++ b/core/modules/contact/src/Plugin/migrate/source/d6/ContactCategory.php
@@ -42,8 +42,8 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     $row->setSourceProperty('recipients', explode(',', $row->getSourceProperty('recipients')));
+    return parent::prepareRow($row);
   }
 
   /**
reverted:
--- b/core/modules/field/src/Plugin/migrate/source/d6/Field.php
+++ a/core/modules/field/src/Plugin/migrate/source/d6/Field.php
@@ -69,7 +69,6 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     // Unserialize data.
     $global_settings = unserialize($row->getSourceProperty('global_settings'));
     $widget_settings = unserialize($row->getSourceProperty('widget_settings'));
@@ -77,6 +76,7 @@
     $row->setSourceProperty('global_settings', $global_settings);
     $row->setSourceProperty('widget_settings', $widget_settings);
     $row->setSourceProperty('db_columns', $db_columns);
+    return parent::prepareRow($row);
   }
 
   /**
reverted:
--- b/core/modules/field/src/Plugin/migrate/source/d6/FieldInstance.php
+++ a/core/modules/field/src/Plugin/migrate/source/d6/FieldInstance.php
@@ -57,7 +57,6 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     // Unserialize data.
     $widget_settings = unserialize($row->getSourceProperty('widget_settings'));
     $display_settings = unserialize($row->getSourceProperty('display_settings'));
@@ -65,6 +64,7 @@
     $row->setSourceProperty('widget_settings', $widget_settings);
     $row->setSourceProperty('display_settings', $display_settings);
     $row->setSourceProperty('global_settings', $global_settings);
+    return parent::prepareRow($row);
   }
 
   /**
reverted:
--- b/core/modules/file/src/Plugin/migrate/source/d6/File.php
+++ a/core/modules/file/src/Plugin/migrate/source/d6/File.php
@@ -75,10 +75,10 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     $row->setSourceProperty('file_directory_path', $this->filePath);
     $row->setSourceProperty('temp_directory_path', $this->tempFilePath);
     $row->setSourceProperty('is_public', $this->isPublic);
+    return parent::prepareRow($row);
   }
 
   /**
diff -u b/core/modules/file/src/Plugin/migrate/source/d6/Upload.php b/core/modules/file/src/Plugin/migrate/source/d6/Upload.php
--- b/core/modules/file/src/Plugin/migrate/source/d6/Upload.php
+++ b/core/modules/file/src/Plugin/migrate/source/d6/Upload.php
@@ -41,13 +41,13 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     $query = $this->select('upload', 'u')
       ->fields('u', array('fid', 'description', 'list'))
       ->condition('u.nid', $row->getSourceProperty('nid'))
       ->orderBy('u.weight');
     $query->innerJoin('node', 'n', static::JOIN);
     $row->setSourceProperty('upload', $query->execute()->fetchAll());
+    return parent::prepareRow($row);
   }
 
   /**
diff -u b/core/modules/file/src/Plugin/migrate/source/d7/File.php b/core/modules/file/src/Plugin/migrate/source/d7/File.php
--- b/core/modules/file/src/Plugin/migrate/source/d7/File.php
+++ b/core/modules/file/src/Plugin/migrate/source/d7/File.php
@@ -63,7 +63,6 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     // Compute the filepath property, which is a physical representation of
     // the URI relative to the Drupal root.
     $path = str_replace(['public:/', 'private:/', 'temporary:/'], [$this->publicPath, $this->privatePath, $this->temporaryPath], $row->getSourceProperty('uri'));
@@ -72,6 +71,7 @@
     // the source_base_path in order to make them all relative.
     $path = str_replace($this->migration->get('destination.source_base_path'), NULL, $path);
     $row->setSourceProperty('filepath', $path);
+    return parent::prepareRow($row);
   }
 
   /**
reverted:
--- b/core/modules/filter/src/Plugin/migrate/source/d6/FilterFormat.php
+++ a/core/modules/filter/src/Plugin/migrate/source/d6/FilterFormat.php
@@ -45,7 +45,6 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     $filters = array();
     $roles = $row->getSourceProperty('roles');
     $row->setSourceProperty('roles', array_values(array_filter(explode(',', $roles))));
@@ -87,6 +86,7 @@
     }
 
     $row->setSourceProperty('filters', $filters);
+    return parent::prepareRow($row);
   }
 
   /**
reverted:
--- b/core/modules/menu_link_content/src/Plugin/migrate/source/d6/MenuLink.php
+++ a/core/modules/menu_link_content/src/Plugin/migrate/source/d6/MenuLink.php
@@ -93,9 +93,10 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     $row->setSourceProperty('options', unserialize($row->getSourceProperty('options')));
     $row->setSourceProperty('enabled', !$row->getSourceProperty('hidden'));
+
+    return parent::prepareRow($row);
   }
 
   /**
reverted:
--- b/core/modules/migrate_drupal/src/Plugin/migrate/source/VariableMultiRow.php
+++ a/core/modules/migrate_drupal/src/Plugin/migrate/source/VariableMultiRow.php
@@ -45,10 +45,10 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     if ($value = $row->getSourceProperty('value')) {
       $row->setSourceProperty('value', unserialize($value));
     }
+    return parent::prepareRow($row);
   }
 
   /**
diff -u b/core/modules/migrate_drupal/src/Plugin/migrate/source/d6/CckFieldValues.php b/core/modules/migrate_drupal/src/Plugin/migrate/source/d6/CckFieldValues.php
--- b/core/modules/migrate_drupal/src/Plugin/migrate/source/d6/CckFieldValues.php
+++ b/core/modules/migrate_drupal/src/Plugin/migrate/source/d6/CckFieldValues.php
@@ -71,7 +71,6 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     $bundle = $row->getSourceProperty('type');
     // Pick up simple CCK fields.
     $cck_table = "content_type_$bundle";
@@ -172,6 +171,7 @@
         }
       }
     }
+    return parent::prepareRow($row);
   }
 
   /**
reverted:
--- b/core/modules/node/src/Plugin/migrate/source/d6/Node.php
+++ a/core/modules/node/src/Plugin/migrate/source/d6/Node.php
@@ -110,12 +110,12 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     // format = 0 can happen when the body field is hidden. Set the format to 1
     // to avoid migration map issues (since the body field isn't used anyway).
     if ($row->getSourceProperty('format') === '0') {
       $row->setSourceProperty('format', $this->filterDefaultFormat);
     }
+    return parent::prepareRow($row);
   }
 
   /**
reverted:
--- b/core/modules/node/src/Plugin/migrate/source/d6/NodeType.php
+++ a/core/modules/node/src/Plugin/migrate/source/d6/NodeType.php
@@ -99,7 +99,6 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     $row->setSourceProperty('teaser_length', $this->teaserLength);
     $row->setSourceProperty('node_preview', $this->nodePreview);
 
@@ -112,6 +111,8 @@
     $row->setSourceProperty('options', $options);
     $submitted = isset($this->themeSettings['toggle_node_info_' . $type]) ? $this->themeSettings['toggle_node_info_' . $type] : FALSE;
     $row->setSourceProperty('display_submitted', $submitted);
+
+    return parent::prepareRow($row);
   }
 
   /**
reverted:
--- b/core/modules/taxonomy/src/Plugin/migrate/source/d6/Term.php
+++ a/core/modules/taxonomy/src/Plugin/migrate/source/d6/Term.php
@@ -58,7 +58,6 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     // Find parents for this row.
     $parents = $this->select('term_hierarchy', 'th')
       ->fields('th', array('parent', 'tid'))
@@ -66,6 +65,7 @@
       ->execute()
       ->fetchCol();
     $row->setSourceProperty('parent', $parents);
+    return parent::prepareRow($row);
   }
 
   /**
reverted:
--- b/core/modules/taxonomy/src/Plugin/migrate/source/d6/TermNode.php
+++ a/core/modules/taxonomy/src/Plugin/migrate/source/d6/TermNode.php
@@ -57,7 +57,6 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     // Select the terms belonging to the revision selected.
     $query = $this->select('term_node', 'tn')
       ->fields('tn', array('tid'))
@@ -65,6 +64,7 @@
     $query->join('node', 'n', static::JOIN);
     $query->innerJoin('term_data', 'td', 'td.tid = tn.tid AND td.vid = :vid', array(':vid' => $this->configuration['vid']));
     $row->setSourceProperty('tid', $query->execute()->fetchCol());
+    return parent::prepareRow($row);
   }
 
   /**
reverted:
--- b/core/modules/taxonomy/src/Plugin/migrate/source/d6/Vocabulary.php
+++ a/core/modules/taxonomy/src/Plugin/migrate/source/d6/Vocabulary.php
@@ -23,7 +23,6 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     // Find node types for this row.
     $node_types = $this->select('vocabulary_node_types', 'nt')
       ->fields('nt', array('type', 'vid'))
@@ -31,6 +30,7 @@
       ->execute()
       ->fetchCol();
     $row->setSourceProperty('node_types', $node_types);
+    return parent::prepareRow($row);
   }
 
   /**
reverted:
--- b/core/modules/user/src/Plugin/migrate/source/d6/ProfileField.php
+++ a/core/modules/user/src/Plugin/migrate/source/d6/ProfileField.php
@@ -48,7 +48,6 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     if ($row->getSourceProperty('type') == 'selection') {
       // Get the current options.
       $current_options = preg_split("/[\r\n]+/", $row->getSourceProperty('options'));
@@ -66,6 +65,8 @@
       // keys.
       $row->setSourceProperty('options', array(NULL, NULL));
     }
+
+    return parent::prepareRow($row);
   }
 
   /**
reverted:
--- b/core/modules/user/src/Plugin/migrate/source/d6/ProfileFieldValues.php
+++ a/core/modules/user/src/Plugin/migrate/source/d6/ProfileFieldValues.php
@@ -36,7 +36,6 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     // Find profile values for this row.
     $query = $this->select('profile_values', 'pv')
       ->fields('pv', array('fid', 'value'));
@@ -60,6 +59,8 @@
         $row->setSourceProperty($profile_value['name'], array($profile_value['value']));
       }
     }
+
+    return parent::prepareRow($row);
   }
 
   /**
reverted:
--- b/core/modules/user/src/Plugin/migrate/source/d6/Role.php
+++ a/core/modules/user/src/Plugin/migrate/source/d6/Role.php
@@ -68,7 +68,6 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     $rid = $row->getSourceProperty('rid');
     $permissions = $this->select('permission', 'p')
       ->fields('p', array('perm'))
@@ -79,6 +78,7 @@
     if (isset($this->filterPermissions[$rid])) {
       $row->setSourceProperty("filter_permissions:$rid", $this->filterPermissions[$rid]);
     }
+    return parent::prepareRow($row);
   }
 
   /**
reverted:
--- b/core/modules/user/src/Plugin/migrate/source/d6/User.php
+++ a/core/modules/user/src/Plugin/migrate/source/d6/User.php
@@ -53,7 +53,6 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     // User roles.
     $roles = $this->select('users_roles', 'ur')
       ->fields('ur', array('rid'))
@@ -79,6 +78,8 @@
 
     // Unserialize Data.
     $row->setSourceProperty('data', unserialize($row->getSourceProperty('data')));
+
+    return parent::prepareRow($row);
   }
 
   /**
reverted:
--- b/core/modules/user/src/Plugin/migrate/source/d6/UserPictureFile.php
+++ a/core/modules/user/src/Plugin/migrate/source/d6/UserPictureFile.php
@@ -57,10 +57,10 @@
    * {@inheritdoc}
    */
   public function prepareRow(Row $row) {
-    parent::prepareRow($row);
     $row->setSourceProperty('filename', basename($row->getSourceProperty('picture')));
     $row->setSourceProperty('file_directory_path', $this->filePath);
     $row->setSourceProperty('temp_directory_path', $this->tempFilePath);
+    return parent::prepareRow($row);
   }
 
   /**
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/migrate/tests/migrate_prepare_row_test/migrate_prepare_row_test.info.yml
@@ -0,0 +1,6 @@
+name: 'Migrate module prepareRow tests'
+type: module
+description: 'Support module for source plugin prepareRow testing.'
+package: Testing
+version: VERSION
+core: 8.x
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/migrate/tests/migrate_prepare_row_test/migrate_prepare_row_test.module
@@ -0,0 +1,29 @@
+<?php
+
+/**
+ * @file
+ * Test module for testing the migration source plugin prepareRow() exception
+ * handling.
+ *
+ * @see \Drupal\migrate\Tests\NodeQueryAlterTest
+ * @see \Drupal\migrate\Tests\NodeAccessBaseTableTest
+ */
+
+use Drupal\migrate\Entity\MigrationInterface;
+use Drupal\migrate\MigrateSkipRowException;
+use Drupal\migrate\Plugin\MigrateSourceInterface;
+use Drupal\migrate\Row;
+
+/**
+ * Implements hook_migrate_prepare_row().
+ */
+function migrate_prepare_row_test_migrate_prepare_row(Row $row, MigrateSourceInterface $source, MigrationInterface $migration) {
+  // Test both options for record_in_map.
+  $instruction = $row->getSourceProperty('instruction');
+  if ($instruction == 'skip_and_record') {
+    throw new MigrateSkipRowException('', TRUE);
+  }
+  elseif ($instruction == 'skip_and_dont_record') {
+    throw new MigrateSkipRowException('', FALSE);
+  }
+}