--- /dev/null
+<?php
+
+namespace Drupal\taxonomy\Plugin\migrate\source\d6;
+
+use Drupal\migrate\Row;
+use Drupal\migrate_drupal\Plugin\migrate\source\DrupalSqlBase;
+
+/**
+ * Source returning tids from the term_node table for the current revision.
+ *
+ * @MigrateSource(
+ * id = "d6_term_node",
+ * source_provider = "taxonomy"
+ * )
+ */
+class TermNode extends DrupalSqlBase {
+
+ /**
+ * The join options between the node and the term node table.
+ */
+ const JOIN = 'tn.vid = n.vid';
+
+ /**
+ * {@inheritdoc}
+ */
+ public function query() {
+ $query = $this->select('term_node', 'tn')
+ ->distinct()
+ ->fields('tn', ['nid', 'vid'])
+ ->fields('n', ['type']);
+ // Because this is an inner join it enforces the current revision.
+ $query->innerJoin('term_data', 'td', 'td.tid = tn.tid AND td.vid = :vid', [':vid' => $this->configuration['vid']]);
+ $query->innerJoin('node', 'n', static::JOIN);
+ return $query;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function fields() {
+ return [
+ 'nid' => $this->t('The node revision ID.'),
+ 'vid' => $this->t('The node revision ID.'),
+ 'tid' => $this->t('The term ID.'),
+ ];
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function prepareRow(Row $row) {
+ // Select the terms belonging to the revision selected.
+ $query = $this->select('term_node', 'tn')
+ ->fields('tn', ['tid'])
+ ->condition('n.nid', $row->getSourceProperty('nid'));
+ $query->join('node', 'n', static::JOIN);
+ $query->innerJoin('term_data', 'td', 'td.tid = tn.tid AND td.vid = :vid', [':vid' => $this->configuration['vid']]);
+ $row->setSourceProperty('tid', $query->execute()->fetchCol());
+ return parent::prepareRow($row);
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getIds() {
+ $ids['vid']['type'] = 'integer';
+ $ids['vid']['alias'] = 'tn';
+ return $ids;
+ }
+
+}