field_sql_storage_field_storage_write does not properly update fields that have additional language values removed

I am currently trying to implement a very light weight system where I make use of the language system in drupal. Currently if you save a node with a field that has multiple language options and then try to update that node by removing one of those languages, the removed language item in the field array is not removed. See below

Brief example
$node = new std Class();
$node->some_field['en'][0]['value'] = 'Something in english';
$node->some_field['fr'][0]['value'] = 'Something in french';
node_save($node);

After the node has been saved you do the following
$node = node_load('nid from above');
$node->some_field = array();
$node->some_field['en'][0]['value'] = 'Something in english';
node_save($node);

If you look in the the database in the field table you will notice that the 'fr' row was not removed.

Looking into this it look like it because of the way field_sql_storage_field_storage_write handles updates

See my comment about 12 lines in:

function field_sql_storage_field_storage_write($entity_type, $entity, $op, $fields) {
  list($id, $vid, $bundle) = entity_extract_ids($entity_type, $entity);
  if (!isset($vid)) {
    $vid = $id;
  }

  foreach ($fields as $field_id) {
    $field = field_info_field_by_id($field_id);
    $field_name = $field['field_name'];
    $table_name = _field_sql_storage_tablename($field);
    $revision_name = _field_sql_storage_revision_tablename($field);

    $all_languages = field_available_languages($entity_type, $field);



   //THIS LINE BELOW is saying only delete languages the are currently defined in the incoming entity. So if 'fr' was removed, it would never know to remove it.

    $field_languages = array_intersect($all_languages, array_keys((array) $entity->$field_name));

    // Delete and insert, rather than update, in case a value was added.
    if ($op == FIELD_STORAGE_UPDATE) {
      // Delete languages present in the incoming $entity->$field_name.
      // Delete all languages if $entity->$field_name is empty.
      $languages = !empty($entity->$field_name) ? $field_languages : $all_languages;
      if ($languages) {
        db_delete($table_name)->condition('entity_type', $entity_type)->condition('entity_id', $id)->condition('language', $languages, 'IN')->execute();
        db_delete($revision_name)->condition('entity_type', $entity_type)->condition('entity_id', $id)->condition('revision_id', $vid)->condition('language', $languages, 'IN')->execute();
      }
    }

    // Prepare the multi-insert query.
    $do_insert = FALSE;
    $columns = array(
      'entity_type',
      'entity_id',
      'revision_id',
      'bundle',
      'delta',
      'language',
    );
    foreach ($field['columns'] as $column => $attributes) {
      $columns[] = _field_sql_storage_columnname($field_name, $column);
    }
    $query = db_insert($table_name)->fields($columns);
    $revision_query = db_insert($revision_name)->fields($columns);

    foreach ($field_languages as $langcode) {
      $items = (array) $entity->{$field_name}[$langcode];
      $delta_count = 0;
      foreach ($items as $delta => $item) {
        // We now know we have someting to insert.
        $do_insert = TRUE;
        $record = array(
          'entity_type' => $entity_type,
          'entity_id' => $id,
          'revision_id' => $vid,
          'bundle' => $bundle,
          'delta' => $delta,
          'language' => $langcode,
        );
        foreach ($field['columns'] as $column => $attributes) {
          $record[_field_sql_storage_columnname($field_name, $column)] = isset($item[$column]) ? $item[$column] : NULL;
        }
        $query->values($record);
        if (isset($vid)) {
          $revision_query->values($record);
        }

        if ($field['cardinality'] != FIELD_CARDINALITY_UNLIMITED && ++$delta_count == $field['cardinality']) {
          break;
        }
      }
    }

    // Execute the query if we have values to insert.
    if ($do_insert) {
      $query->execute();
      $revision_query->execute();
    }
  }
}

See my suggested attached patch