Undefined index in CRM_Core_BAO_SchemaHandler::getMissingIndices()

Since the recent addition of checks for indices, we've begun seeing warnings like:

Notice: Undefined index: civicrm_location_type in CRM_Core_BAO_SchemaHandler::getMissingIndices() (line 747 of /path/to/civicrm/CRM/Core/BAO/SchemaHandler.php).
Warning: Invalid argument supplied for foreach() in CRM_Core_BAO_SchemaHandler::getMissingIndices() (line 747 of /path/to/civicrm/CRM/Core/BAO/SchemaHandler.php).

We're seeing a couple pages worth of these warnings, where the indicated index is one of:

• civicrm_location_type
• civicrm_option_group
• civicrm_relationship_type
• civicrm_contact_type
• civicrm_batch
• civicrm_survey
• civicrm_case_type
• civicrm_custom_group
• civicrm_custom_field
• civicrm_option_value
• civicrm_group
• civicrm_membership_type
• civicrm_price_set
• civicrm_uf_group
• civicrm_uf_field
• civicrm_event

These warnings include multiple instances of some of the above.

The code in question (around line 740 in CRM/Core/BAO/SchemaHandler.php) is:

   // Get missing indices
    $missingIndices = array();
    foreach ($missingSigs as $sig) {
      $sigParts = explode('::', $sig);
      foreach ($requiredIndices[$sigParts[0]] as $index) {
        if ($index['sig'] == $sig) {
          $missingIndices[$sigParts[0]][] = $index;
          continue;
        }
      }
    }

Specifically, the problem is with:

foreach ($requiredIndices[$sigParts[0]] as $index) { 

Some of the indices in $requiredIndices are localized, whereas the signature that's being used as the key (from $missingSigs) is not.

For example, $requiredIndices['civicrm_location_type_en_US'] looks like:

array (
  'UI_name' =>
  array (
    'name' => 'UI_name',
    'field' =>
    array(
      0 => 'name,
    ),
    'localizable' => FALSE,
    'unique' => TRUE,
    'sig' => 'civicrm_location_type::1::name',
  ),
)

Whereas we're iterating over $missingSigs, where the equivalent item that'll be used as a key for $requiredIndices is: civicrm_location_type::1::name.