From be4f9ceb19001387bd02b4d81ad216fd690d7203 Mon Sep 17 00:00:00 2001
From: David Balch <david@balch.co.uk>
Date: Thu, 19 Oct 2017 09:32:07 +0100
Subject: [PATCH] Make tool_consumer_instance_guid optional

In the specification, tool_consumer_instance_guid is only listed as recommended. https://www.imsglobal.org/specs/ltiv2p0/implementation-guide#toc-42 - however the library was requiring it.
---
 src/ToolProvider/ToolProvider.php | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/src/ToolProvider/ToolProvider.php b/src/ToolProvider/ToolProvider.php
index b78b03e..d79842a 100644
--- a/src/ToolProvider/ToolProvider.php
+++ b/src/ToolProvider/ToolProvider.php
@@ -808,11 +808,6 @@ private function authenticate()
                         if (!$this->ok) {
                             $this->reason = 'Request is from an invalid tool consumer.';
                         }
-                    } else {
-                        $this->ok = isset($_POST['tool_consumer_instance_guid']);
-                        if (!$this->ok) {
-                            $this->reason = 'A tool consumer GUID must be included in the launch request.';
-                        }
                     }
                 }
                 if ($this->ok) {