From 0219831af44abb64f1902e92b88b1e5e1c107523 Mon Sep 17 00:00:00 2001
From: Ilya Tregubov <ilya.a.tregubov@gmail.com>
Date: Mon, 6 May 2024 12:14:32 +0800
Subject: [PATCH 1/2] MDL-51360 mod_quiz: Don't do full course recalculation.

It seems it was never needed. We only need to know if just one
grade is overridden and its value.
---
 mod/quiz/view.php | 36 ++++++++++++++++++++++++------------
 1 file changed, 24 insertions(+), 12 deletions(-)

diff --git a/mod/quiz/view.php b/mod/quiz/view.php
index 53d9bc79fec..7da171c8d3d 100644
--- a/mod/quiz/view.php
+++ b/mod/quiz/view.php
@@ -126,21 +126,33 @@ if (!$canpreview) {
 $mygradeoverridden = false;
 $gradebookfeedback = '';
 
-$item = null;
-
-$gradinginfo = grade_get_grades($course->id, 'mod', 'quiz', $quiz->id, $USER->id);
-if (!empty($gradinginfo->items)) {
-    $item = $gradinginfo->items[0];
-    if (isset($item->grades[$USER->id])) {
-        $grade = $item->grades[$USER->id];
+$gradeitem = grade_item::fetch([
+    'itemtype' => 'mod',
+    'itemmodule' => 'quiz',
+    'iteminstance' => $quiz->id,
+    'itemnumber' => 0,
+    'courseid' => $course->id,
+]);
 
+if ($gradeitem) {
+    if ($gradeitem->refresh_grades($USER->id)) {
+        $grade = $gradeitem->get_grade($USER->id, false);
         if ($grade->overridden) {
-            $mygrade = $grade->grade + 0; // Convert to number.
+            if ($gradeitem->needsupdate) {
+                // It is Error, but let's be consistent with the old code.
+                $mygrade = 0;
+            } else {
+                $mygrade = $grade->finalgrade;
+            }
             $mygradeoverridden = true;
         }
-        if (!empty($grade->str_feedback)) {
-            $gradebookfeedback = $grade->str_feedback;
+
+        if (!empty($grade->feedback)) {
+            $gradebookfeedback = $grade->feedback;
         }
+    } else {
+        // It is Error, but let's be consistent with the old code.
+        $mygrade = 0;
     }
 }
 
@@ -197,9 +209,9 @@ if ($quiz->attempts != 1) {
 }
 
 // Inform user of the grade to pass if non-zero.
-if ($item && grade_floats_different($item->gradepass, 0)) {
+if ($gradeitem && grade_floats_different($gradeitem->gradepass, 0)) {
     $a = new stdClass();
-    $a->grade = quiz_format_grade($quiz, $item->gradepass);
+    $a->grade = quiz_format_grade($quiz, $gradeitem->gradepass);
     $a->maxgrade = quiz_format_grade($quiz, $quiz->grade);
     $viewobj->infomessages[] = get_string('gradetopassoutof', 'quiz', $a);
 }

From 7fc818ebb8a8c23f804a85c40f3c58a92ae873af Mon Sep 17 00:00:00 2001
From: Ilya Tregubov <ilya.a.tregubov@gmail.com>
Date: Thu, 9 May 2024 14:57:05 +0800
Subject: [PATCH 2/2] MDL-51360 core_grades: Improve documentation of
 grade_get_grades().

---
 lib/gradelib.php | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/lib/gradelib.php b/lib/gradelib.php
index 770a233ab83..a0e444744d1 100644
--- a/lib/gradelib.php
+++ b/lib/gradelib.php
@@ -430,10 +430,14 @@ function grade_regrade_final_grades_if_required($course, callable $callback = nu
 }
 
 /**
- * Returns grading information for given activity, optionally with user grades
+ * Returns grading information for given activity, optionally with user grades.
  * Manual, course or category items can not be queried.
  *
- * @category grade
+ * This function can be VERY costly - it is doing full course grades recalculation if needsupdate = 1
+ * for course grade item. So be sure you really need it.
+ * If you need just certain grades consider using grade_item::refresh_grades()
+ * together with grade_item::get_grade() instead.
+ *
  * @param int    $courseid ID of course
  * @param string $itemtype Type of grade item. For example, 'mod' or 'block'
  * @param string $itemmodule More specific then $itemtype. For example, 'forum' or 'quiz'. May be NULL for some item types
@@ -441,6 +445,7 @@ function grade_regrade_final_grades_if_required($course, callable $callback = nu
  * @param mixed  $userid_or_ids Either a single user ID, an array of user IDs or null. If user ID or IDs are not supplied returns information about grade_item
  * @return stdClass Object with keys {items, outcomes, errors}, where 'items' is an array of grade
  *               information objects (scaleid, name, grade and locked status, etc.) indexed with itemnumbers
+ * @category grade
  */
 function grade_get_grades($courseid, $itemtype, $itemmodule, $iteminstance, $userid_or_ids=null) {
     global $CFG;