From 87914aa40720a88b40fddc029c325e7dd2c8e45e Mon Sep 17 00:00:00 2001
From: Frederic Massart <fred@moodle.com>
Date: Thu, 5 Feb 2015 15:06:32 +0800
Subject: [PATCH] MDL-47953 gradereport_grader: Accurate pagination with
 suspended users

Thanks to Zvonko Martinovic for pointing out the source of the bug.
---
 grade/report/grader/lib.php | 53 ++++++++++++++++++++-----------------
 1 file changed, 29 insertions(+), 24 deletions(-)

diff --git a/grade/report/grader/lib.php b/grade/report/grader/lib.php
index d6700dd92f7..fb83a55e23a 100644
--- a/grade/report/grader/lib.php
+++ b/grade/report/grader/lib.php
@@ -415,8 +415,14 @@ class grade_report_grader extends grade_report {
         // Limit to users with a gradeable role.
         list($gradebookrolessql, $gradebookrolesparams) = $DB->get_in_or_equal(explode(',', $this->gradebookroles), SQL_PARAMS_NAMED, 'grbr0');
 
+        // Check the status of showing only active enrolments.
+        $coursecontext = $this->context->get_course_context(true);
+        $defaultgradeshowactiveenrol = !empty($CFG->grade_report_showonlyactiveenrol);
+        $showonlyactiveenrol = get_user_preferences('grade_report_showonlyactiveenrol', $defaultgradeshowactiveenrol);
+        $showonlyactiveenrol = $showonlyactiveenrol || !has_capability('moodle/course:viewsuspendedusers', $coursecontext);
+
         // Limit to users with an active enrollment.
-        list($enrolledsql, $enrolledparams) = get_enrolled_sql($this->context);
+        list($enrolledsql, $enrolledparams) = get_enrolled_sql($this->context, '', 0, $showonlyactiveenrol);
 
         // Fields we need from the user table.
         $userfields = user_picture::fields('u', get_extra_user_fields($this->context));
@@ -479,30 +485,29 @@ class grade_report_grader extends grade_report {
             $this->userselect = "AND g.userid $usql";
             $this->userselect_params = $uparams;
 
-            // Add a flag to each user indicating whether their enrolment is active.
-            $sql = "SELECT ue.userid
-                      FROM {user_enrolments} ue
-                      JOIN {enrol} e ON e.id = ue.enrolid
-                     WHERE ue.userid $usql
-                           AND ue.status = :uestatus
-                           AND e.status = :estatus
-                           AND e.courseid = :courseid
-                           AND ue.timestart < :now1 AND (ue.timeend = 0 OR ue.timeend > :now2)
-                  GROUP BY ue.userid";
-            $coursecontext = $this->context->get_course_context(true);
-            $time = time();
-            $params = array_merge($uparams, array('estatus' => ENROL_INSTANCE_ENABLED, 'uestatus' => ENROL_USER_ACTIVE,
-                    'courseid' => $coursecontext->instanceid, 'now1' => $time, 'now2' => $time));
-            $useractiveenrolments = $DB->get_records_sql($sql, $params);
-
-            $defaultgradeshowactiveenrol = !empty($CFG->grade_report_showonlyactiveenrol);
-            $showonlyactiveenrol = get_user_preferences('grade_report_showonlyactiveenrol', $defaultgradeshowactiveenrol);
-            $showonlyactiveenrol = $showonlyactiveenrol || !has_capability('moodle/course:viewsuspendedusers', $coursecontext);
+            // First flag everyone as not suspended.
             foreach ($this->users as $user) {
-                // If we are showing only active enrolments, then remove suspended users from list.
-                if ($showonlyactiveenrol && !array_key_exists($user->id, $useractiveenrolments)) {
-                    unset($this->users[$user->id]);
-                } else {
+                $this->users[$user->id]->suspendedenrolment = false;
+            }
+
+            // If we want to mix both suspended and not suspended users, let's find out who is suspended.
+            if (!$showonlyactiveenrol) {
+                $sql = "SELECT ue.userid
+                          FROM {user_enrolments} ue
+                          JOIN {enrol} e ON e.id = ue.enrolid
+                         WHERE ue.userid $usql
+                               AND ue.status = :uestatus
+                               AND e.status = :estatus
+                               AND e.courseid = :courseid
+                               AND ue.timestart < :now1 AND (ue.timeend = 0 OR ue.timeend > :now2)
+                      GROUP BY ue.userid";
+
+                $time = time();
+                $params = array_merge($uparams, array('estatus' => ENROL_INSTANCE_ENABLED, 'uestatus' => ENROL_USER_ACTIVE,
+                        'courseid' => $coursecontext->instanceid, 'now1' => $time, 'now2' => $time));
+                $useractiveenrolments = $DB->get_records_sql($sql, $params);
+
+                foreach ($this->users as $user) {
                     $this->users[$user->id]->suspendedenrolment = !array_key_exists($user->id, $useractiveenrolments);
                 }
             }