From e4f7cfe19f9dcc2d552d80ede0e2cb75b3d87456 Mon Sep 17 00:00:00 2001
From: Ankit Agarwal <ankit@moodle.com>
Date: Tue, 29 Aug 2017 10:31:04 +0530
Subject: [PATCH] MDL-59198 lti: Make params LTI2 compatible

LTI2 recommends to include both upper case and lower case of custom params.
This patch makes our implementation confer to that standard.
---
 mod/lti/locallib.php            | 15 +++++++++------
 mod/lti/tests/locallib_test.php | 10 ++++++++--
 2 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/mod/lti/locallib.php b/mod/lti/locallib.php
index 81e4a4452c34b..f1e57625a3b21 100644
--- a/mod/lti/locallib.php
+++ b/mod/lti/locallib.php
@@ -1165,7 +1165,7 @@ function lti_get_enabled_capabilities($tool) {
  * @param string    $customstr      String containing the parameters
  * @param boolean   $islti2         True if an LTI 2 tool is being launched
  *
- * @return Array of custom parameters
+ * @return array of custom parameters
  */
 function lti_split_custom_parameters($toolproxy, $tool, $params, $customstr, $islti2 = false) {
     $customstr = str_replace("\r\n", "\n", $customstr);
@@ -1179,11 +1179,12 @@ function lti_split_custom_parameters($toolproxy, $tool, $params, $customstr, $is
             continue;
         }
         $key = trim(core_text::substr($line, 0, $pos));
+        $key = lti_map_keyname($key, false);
         $val = trim(core_text::substr($line, $pos + 1, strlen($line)));
         $val = lti_parse_custom_parameter($toolproxy, $tool, $params, $val, $islti2);
         $key2 = lti_map_keyname($key);
         $retval['custom_'.$key2] = $val;
-        if ($islti2 && ($key != $key2)) {
+        if ($key != $key2) {
             $retval['custom_'.$key] = $val;
         }
     }
@@ -1269,14 +1270,16 @@ function lti_parse_custom_parameter($toolproxy, $tool, $params, $value, $islti2)
  * Used for building the names of the different custom parameters
  *
  * @param string $key   Parameter name
- *
+ * @param bool $tolower Do we want to convert the key into lower case?
  * @return string       Processed name
  */
-function lti_map_keyname($key) {
+function lti_map_keyname($key, $tolower = true) {
     $newkey = "";
-    $key = core_text::strtolower(trim($key));
+    if ($tolower) {
+        $key = core_text::strtolower(trim($key));
+    }
     foreach (str_split($key) as $ch) {
-        if ( ($ch >= 'a' && $ch <= 'z') || ($ch >= '0' && $ch <= '9') ) {
+        if ( ($ch >= 'a' && $ch <= 'z') || ($ch >= '0' && $ch <= '9') || (!$tolower && ($ch >= 'A' && $ch <= 'Z'))) {
             $newkey .= $ch;
         } else {
             $newkey .= '_';
diff --git a/mod/lti/tests/locallib_test.php b/mod/lti/tests/locallib_test.php
index 5a471c01d478d..cdc3160335556 100644
--- a/mod/lti/tests/locallib_test.php
+++ b/mod/lti/tests/locallib_test.php
@@ -71,14 +71,20 @@ public function test_split_custom_parameters() {
         $this->assertEquals(lti_split_custom_parameters(null, $tool, array(), "x=1\ny=2", false),
             array('custom_x' => '1', 'custom_y' => '2'));
 
+        // Check params with caps.
+        $this->assertEquals(lti_split_custom_parameters(null, $tool, array(), "X=1", false),
+            array('custom_x' => '1', 'custom_X' => '1'));
+
         // Removed repeat of previous test with a semicolon separator.
 
         $this->assertEquals(lti_split_custom_parameters(null, $tool, array(), 'Review:Chapter=1.2.56', false),
-            array('custom_review_chapter' => '1.2.56'));
+            array('custom_review_chapter' => '1.2.56', 'custom_Review_Chapter' => '1.2.56'));
 
         $this->assertEquals(lti_split_custom_parameters(null, $tool, array(),
             'Complex!@#$^*(){}[]KEY=Complex!@#$^*;(){}[]½Value', false),
-            array('custom_complex____________key' => 'Complex!@#$^*;(){}[]½Value'));
+            array(
+                'custom_complex____________key' => 'Complex!@#$^*;(){}[]½Value',
+                'custom_Complex____________KEY' => 'Complex!@#$^*;(){}[]½Value'));
 
         // Test custom parameter that returns $USER property.
         $user = $this->getDataGenerator()->create_user(array('middlename' => 'SOMETHING'));