Learnpath: Add sanity checks in the lp-specific user subscription configuration page to avoir null errors - refs BT#17726

main/lp/lp_subscribe_users.php

@@ -94,8 +94,15 @@ $subscribedUsersInLp = $itemRepo->getUsersSubscribedToItem(
 );
 
 $selectedChoices = [];
+if (!empty($subscribedUsersInLp)) {
     foreach ($subscribedUsersInLp as $itemProperty) {
-    $selectedChoices[] = $itemProperty->getToUser()->getId();
+        if (!empty($itemProperty)) {
+            $getToUser = $itemProperty->getToUser();
+            if (!empty($getToUser)) {
+                $selectedChoices[] = $getToUser->getId();
+            }
+        }
+    }
 }
 
 //Building the form for Users
@@ -140,9 +147,16 @@ $subscribedGroupsInLp = $itemRepo->getGroupsSubscribedToItem(
 
 $selectedGroupChoices = [];
 /** @var CItemProperty $itemProperty */
+if (!empty($subscribedGroupsInLp)) {
     foreach ($subscribedGroupsInLp as $itemProperty) {
+        if (!empty($itemProperty)) {
+            $getGroup = $itemProperty->getGroup();
+            if (!empty($getGroup)) {
                 $selectedGroupChoices[] = $itemProperty->getGroup()->getId();
             }
+        }
+    }
+}
 
 $groupMultiSelect = $form->addElement(
     'advmultiselect',