field_sql_storage_schema() does not remove the field_config_entity_type table

I'm guessing because field_sql_storage_schema() does a check for db_table_exists('field_config') during field_sql_storage_uninstall(), the field_config tables have already been removed, so that part of the schema does not get removed.

The field_config_entity_type is currently owned by field_sql_storage.module. I don't know why it wouldn't be dropped when that module is uninstalled.

I can't decide if that table and the function that populates it (_field_sql_storage_etid()) should be part of field.module or not. Other storage engines may not have any need to map entity types to ids, suggesting it belongs in field_sql_storage. However, any storage engine that uses the SQL database will need it, so not having it in field.module potentially causes duplicate code.

Comments welcome.

So...I can't believe it was this obvious:

/**
 * Implementation of hook_schema().
 */
function field_sql_storage_schema() {
  $schema = array();

  // Static (meta-data) tables.
  $schema['field_config_entity_type'] = array(
    'fields' => array(
      'etid' => array(
        'type' => 'serial',
        'unsigned' => TRUE,
        'not null' => TRUE,
        'description' => 'The unique id for this entity type',
      ),
      'type' => array(
        'type' => 'varchar',
        'length' => 255,
        'not null' => TRUE,
        'description' => 'An entity type',
      ),
    ),
    'primary key' => array('etid'),
    'unique keys' => array('type' => array('type')),
  );

  // Dynamic (data) tables.
  if (db_table_exists('field_config')) {
    $fields = field_read_fields();
    drupal_load('module', 'field_sql_storage');
>>>>  $schema = array(); <<<< THIS RESETS THE ARRAY AND AFFECTS THE UNINSTALL!!! ARG!
    foreach ($fields as $field) {
      $schema += _field_sql_storage_schema($field);
    }
  }
  return $schema;
}

For some reason now I'm getting just two tables left over after running the field tests:
simpletest792411field_data_revision_test_field_name
simpletest792411field_data_test_field_name

Investigating further to see why those aren't being removed now.

Managed to find what was going on. The two tables that were being left over was caused by the test FieldTestCase->testDeleteField where a field is marked as 'deleted' but the FieldAPI does not actually remove the tables. Then, in field_sql_storage_schema(), the function field_read_fields() is called to get all the field tables, but that function, by default does not include 'deleted' or 'inactive' fields. Luckily, there's an easy parameter change and all the tables uninstall cleanly now!

Both changes look good. The first is an obvious bug, and for the second: deleted fields are supposed to be invisible to Field API callers but the tables do in fact still exist and so ought to be reported in the schema. RTBC.

Actually, #10 contains the change in #6, so only #10 is needed.

Committed to HEAD. Thanks!