Duplicate entries in in forum_index table

Edited forum posts showing up twice in forum list is still an issue in 7.x-1.x-dev release from 2012-Aug-10.

Forum posts are displayed twice in the list of forum posts, after they are edited. In the forum_index table the post appears twice, with identical content, which is why it is shown twice.

To reproduce:

1. Install Drupal Core forum and File (Field) Paths
2. Create a forum post
3. Edit it
4. View the forum, the edited post is displayed twice

Not a fix, but a quick workaround.

function HOOK_entity_update($entity, $type) {
  if ($type == 'node' && function_exists('_forum_node_check_node_type')) {
    if (_forum_node_check_node_type($entity)) {
      $query = db_select('forum_index', 'f')
        ->condition('nid', $entity->nid)
        ->fields('f');
      $query->addExpression('count(*)', 'count');
      $query->addExpression("concat( nid, '_', tid)", 'concat_id');
      $query->groupBy('concat_id');
      $query->havingCondition('count', 1, '>');
      $result = $query->execute();
      foreach ($result as $row) {
        db_delete('forum_index')->condition('nid', $row->nid)->condition('tid', $row->tid)->execute();
        drupal_write_record('forum_index', $row);
      }
    }
  }
}

This is a duplicate of #1464404: field_attach_update() causes OG memberships to be deleted upon user signup

Confirmed as still an active issue.

Fix committed.