Removing passing in the object to prevent any possible confusion and just using the datastream->parent.

includes/datastream.inc

@@ -296,7 +296,7 @@ function islandora_datastream_get_url(AbstractDatastream $datastream, $type = 'd
 function islandora_edit_datastream(AbstractDatastream $datastream) {
   module_load_include('inc', 'islandora', 'includes/utilities');
 
-  $edit_registry = islandora_build_datastream_edit_registry($datastream->parent, $datastream);
+  $edit_registry = islandora_build_datastream_edit_registry($datastream);
   $edit_count = count($edit_registry);
   switch ($edit_count) {
     case 0:

includes/utilities.inc

@@ -950,18 +950,16 @@ function islandora_deployed_on_windows() {
 /**
  * Build the edit registry for a given datastream.
  *
- * @param AbstractObject $object
- *   The object being edited.
  * @param AbstractDatastream $datastream
  *   The datastream being edited.
  *
  * @return array
  *   The built edit registry array.
  */
-function islandora_build_datastream_edit_registry($object, $datastream) {
-  $edit_registry = module_invoke_all(ISLANDORA_EDIT_DATASTREAM_REGISTRY_HOOK, $object, $datastream);
+function islandora_build_datastream_edit_registry(AbstractDatastream $datastream) {
+  $edit_registry = module_invoke_all(ISLANDORA_EDIT_DATASTREAM_REGISTRY_HOOK, $datastream->parent, $datastream);
   $context = array(
-    'object' => $object,
+    'object' => $datastream->parent,
     'datastream' => $datastream,
     'original_edit_registry' => $edit_registry,
   );

theme/theme.inc

@@ -535,7 +535,7 @@ function theme_islandora_datastream_edit_link(array $vars) {
   $datastream = $vars['datastream'];
   module_load_include('inc', 'islandora', 'includes/utilities');
 
-  $edit_registry = islandora_build_datastream_edit_registry($datastream->parent, $datastream);
+  $edit_registry = islandora_build_datastream_edit_registry($datastream);
 
   $can_edit = count($edit_registry) > 0 && islandora_datastream_access(ISLANDORA_METADATA_EDIT, $datastream);