datalist-for-backlinks.patch

diff --git a/code/Model/SiteTree.php b/code/Model/SiteTree.php
index 85be8e33..859f41de 100755
--- a/code/Model/SiteTree.php
+++ b/code/Model/SiteTree.php
@@ -1727,10 +1727,11 @@ class SiteTree extends DataObject implements PermissionProvider, i18nEntityProvi
     /**
      * Get the back-link tracking objects that link to this page
      *
-     * @retun ArrayList|DataObject[]
+     * @return DataList|DataObject[]
      */
     public function BackLinkTracking()
     {
+        return $this->BackLinks();
         // @todo - Implement PolymorphicManyManyList to replace this
         $list = ArrayList::create();
         foreach ($this->BackLinks() as $link) {
@@ -1747,7 +1748,7 @@ class SiteTree extends DataObject implements PermissionProvider, i18nEntityProvi
      * Returns the pages that depend on this page. This includes virtual pages, pages that link to it, etc.
      *
      * @param bool $includeVirtuals Set to false to exlcude virtual pages.
-     * @return ArrayList|SiteTree[]
+     * @return DataList|SiteTree[]
      */
     public function DependentPages($includeVirtuals = true)
     {
@@ -1757,43 +1758,30 @@ class SiteTree extends DataObject implements PermissionProvider, i18nEntityProvi
         }
 
         // Content links
-        $items = new ArrayList();
+        $items = DataList::create(SiteTree::class);
+        $filterByIds = [];
 
-        // We merge all into a regular SS_List, because DataList doesn't support merge
         if ($contentLinks = $this->BackLinkTracking()) {
-            $linkList = new ArrayList();
-            foreach ($contentLinks as $item) {
-                $item->DependentLinkType = 'Content link';
-                $linkList->push($item);
-            }
-            $items->merge($linkList);
+            $filterByIds = array_merge($filterByIds, $contentLinks->column('ID'));
         }
 
         // Virtual pages
         if ($includeVirtuals) {
             $virtuals = $this->VirtualPages();
-            if ($virtuals) {
-                $virtualList = new ArrayList();
-                foreach ($virtuals as $item) {
-                    $item->DependentLinkType = 'Virtual page';
-                    $virtualList->push($item);
-                }
-                $items->merge($virtualList);
-            }
+            $filterByIds = array_merge($filterByIds, $virtuals->column('ID'));
         }
 
         // Redirector pages
-        $redirectors = RedirectorPage::get()->where(array(
+        $redirectors = RedirectorPage::get()->where([
             '"RedirectorPage"."RedirectionType"' => 'Internal',
             '"RedirectorPage"."LinkToID"' => $this->ID
-        ));
+        ]);
         if ($redirectors) {
-            $redirectorList = new ArrayList();
-            foreach ($redirectors as $item) {
-                $item->DependentLinkType = 'Redirector page';
-                $redirectorList->push($item);
-            }
-            $items->merge($redirectorList);
+            $filterByIds = array_merge($filterByIds, $redirectors->column('ID'));
+        }
+
+        if (count($filterByIds)) {
+            $items = $items->filter(['ID' => $filterByIds]);
         }
 
         if (class_exists('Subsite')) {