From 3632537b5b11f4dca3ca063678e9d1d0ad1fa17f Mon Sep 17 00:00:00 2001
From: Daniel Neis Araujo <danielneis@gmail.com>
Date: Wed, 15 Dec 2021 18:38:06 -0300
Subject: [PATCH] MDL-73378 gradebook: Category grade null when all subgrades
 are null

---
 lib/grade/grade_category.php | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/lib/grade/grade_category.php b/lib/grade/grade_category.php
index 88b4028f2a7..6dfb3fa5818 100644
--- a/lib/grade/grade_category.php
+++ b/lib/grade/grade_category.php
@@ -722,6 +722,16 @@ class grade_category extends grade_object {
 
         }
 
+        // First, check if all grades are null, because the final grade will be null
+        // even when aggreateonlygraded is true.
+        $allnull = true;
+        foreach ($grade_values as $v) {
+            if (!is_null($v)) {
+                $allnull = false;
+                break;
+            }
+        }
+
         // For items with no value, and not excluded - either set their grade to 0 or exclude them.
         foreach ($items as $itemid=>$value) {
             if (!isset($grade_values[$itemid]) and !in_array($itemid, $excluded)) {
@@ -789,9 +799,13 @@ class grade_category extends grade_object {
             $result['grademin'] = 0;
         }
 
-        // Recalculate the grade back to requested range.
-        $finalgrade = grade_grade::standardise_score($agg_grade, 0, 1, $result['grademin'], $result['grademax']);
-        $grade->finalgrade = $this->grade_item->bounded_grade($finalgrade);
+        if ($allnull) {
+            $grade->finalgrade = null;
+        } else {
+            // Recalculate the grade back to requested range.
+            $finalgrade = grade_grade::standardise_score($agg_grade, 0, 1, $result['grademin'], $result['grademax']);
+            $grade->finalgrade = $this->grade_item->bounded_grade($finalgrade);
+        }
 
         $oldrawgrademin = $grade->rawgrademin;
         $oldrawgrademax = $grade->rawgrademax;