From 9e734d6726e8c757c762d30f50002bd2ef0e8034 Mon Sep 17 00:00:00 2001
From: Kylea Jackson <kyleajackson4@gmail.com>
Date: Mon, 9 Mar 2015 12:57:58 -0300
Subject: [PATCH] Added recursive derivative check

---
 includes/delete_datastream.form.inc | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/includes/delete_datastream.form.inc b/includes/delete_datastream.form.inc
index b7715657..ce1959df 100644
--- a/includes/delete_datastream.form.inc
+++ b/includes/delete_datastream.form.inc
@@ -53,7 +53,14 @@ function islandora_datastream_to_purge(AbstractObject $object, $dsid) {
   $dsid_map = function ($hook_definition) {
     return $hook_definition['destination_dsid'];
   };
-  $dsids = array_map($dsid_map, $hooks);
+  $dsids = array();
+  $derived_dsids = array_map($dsid_map, $hooks);
+  while ($current = array_pop($derived_dsids)) {
+    $dsids[] = $current;
+    $current_derived = islandora_datastream_to_purge($object, $current);
+    $current_diff = array_diff($current_derived, $derived_dsids, $dsids);
+    $derived_dsids = array_merge($derived_dsids, $current_diff);
+  }
   return $dsids;
 }