MDL-61870 mod_assign: Fix/clean up imported group override duedates

- Prevent group override duedate events from being imported when groups are excluded
- Clean up any existing group override duedate events when editing assignment in upgradelib.php
- Updated lib.php unit tests

mod/assign/db/upgrade.php

@@ -171,5 +171,15 @@ function xmldb_assign_upgrade($oldversion) {
     // Automatically generated Moodle v3.5.0 release upgrade line.
     // Put any upgrade step following this.
 
+    if ($oldversion < 2018061100) {
+        require_once($CFG->dirroot.'/mod/assign/upgradelib.php');
+
+        // Clean up duplicate event records that may have been generated from MDL-61870.
+        delete_assignment_duplicate_group_events();
+
+        // Main savepoint reached.
+        upgrade_mod_savepoint(true, 2018061100, 'assign');
+    }
+
     return true;
 }

mod/assign/lib.php

@@ -258,7 +258,7 @@ function assign_update_events($assign, $override = null) {
         // Only load events for this override.
         if (isset($override->userid)) {
             $conds['userid'] = $override->userid;
-        } else {
+        } else if (isset($override->groupid)) {
             $conds['groupid'] = $override->groupid;
         }
     }

mod/assign/tests/lib_test.php

@@ -362,14 +362,23 @@ class mod_assign_lib_testcase extends advanced_testcase {
             ]);
 
         $instance = $assign->get_instance();
-        $eventparams = ['modulename' => 'assign', 'instance' => $instance->id];
+        $eventparams = [
+            'modulename' => 'assign',
+            'instance' => $instance->id,
+            'eventtype' => ASSIGN_EVENT_TYPE_DUE,
+            'groupid' => 0
+        ];
 
         // Make sure the calendar event for assignment 1 matches the initial due date.
         $eventtime = $DB->get_field('event', 'timestart', $eventparams, MUST_EXIST);
         $this->assertEquals($eventtime, $duedate);
 
         // Manually update assignment 1's due date.
-        $DB->update_record('assign', (object) ['id' => $instance->id, 'duedate' => $newduedate]);
+        $DB->update_record('assign', (object) [
+            'id' => $instance->id,
+            'duedate' => $newduedate,
+            'course' => $course->id
+        ]);
 
         // Then refresh the assignment events of assignment 1's course.
         $this->assertTrue(assign_refresh_events($course->id));
@@ -380,15 +389,25 @@ class mod_assign_lib_testcase extends advanced_testcase {
 
         // Create a second course and assignment.
         $othercourse = $this->getDataGenerator()->create_course();;
-        $otherassign = $this->create_instance($othercourse, ['duedate' => $duedate, 'course' => $othercourse->id]);
+        $otherassign = $this->create_instance($othercourse, [
+            'duedate' => $duedate,
+        ]);
         $otherinstance = $otherassign->get_instance();
 
         // Manually update assignment 1 and 2's due dates.
         $newduedate += DAYSECS;
-        $DB->update_record('assign', (object)['id' => $instance->id, 'duedate' => $newduedate]);
-        $DB->update_record('assign', (object)['id' => $otherinstance->id, 'duedate' => $newduedate]);
+        $DB->update_record('assign', (object)[
+            'id' => $instance->id,
+            'duedate' => $newduedate,
+            'course' => $course->id
+        ]);
+        $DB->update_record('assign', (object)[
+            'id' => $otherinstance->id,
+            'duedate' => $newduedate,
+            'course' => $othercourse->id
+        ]);
 
-        // Refresh events of all courses.
+        // Refresh events of all courses and check the calendar events matches the new date.
         $this->assertTrue(assign_refresh_events());
 
         // Check the due date calendar event for assignment 1.

mod/assign/upgradelib.php

@@ -438,3 +438,78 @@ function get_assignments_with_rescaled_null_grades() {
 
     return $assignments;
 }
+
+/**
+ * Determined if the assignment has any duplicate group events generated from
+ * restoring Course backup without groups, and deletes any records found.
+ *
+ * Bug fix data clean up for MDL-61870.
+ */
+function delete_assignment_duplicate_group_events() {
+    global $DB;
+
+    // Get all Course's assign course modules to check for any duplicate group events to remove.
+    list($coursesinsql, $coursesinparams) = $DB->get_in_or_equal(array_keys(get_courses()), SQL_PARAMS_NAMED);
+
+    $query = "SELECT cm.id AS id,
+                     cm.course AS courseid,
+                     cm.instance AS instanceid
+                FROM {course_modules} cm
+                JOIN {modules} m ON m.id = cm.module
+               WHERE m.name = :modulename
+                 AND (cm.course $coursesinsql)";
+    $params = ['modulename' => 'assign'];
+    $params += $coursesinparams;
+
+    foreach ($DB->get_records_sql($query, $params) as $cm) {
+        $selectgroupevents = "courseid = :courseid
+                              AND modulename = :modulename
+                              AND eventtype = :eventtype
+                              AND instance = :instance
+                              AND groupid <> :groupid
+                              AND priority <> :priority";
+        $paramsgroupevents = [
+            'courseid' => $cm->courseid,
+            'modulename' => 'assign',
+            'eventtype' => 'due',
+            'instance' => $cm->instanceid,
+            'groupid' => 0,
+            'priority' => 0
+        ];
+
+        // Retrieve all the Course's assign events associated with group overrides,
+        // which will be use to look for duplicate records that need to be deleted.
+        foreach ($DB->get_records_select('event', $selectgroupevents, $paramsgroupevents) as $groupevent) {
+            // Delete any duplicates that match the details of the current groupevent but the id does not
+            // match the current groupevent id and course id, groupid is 0, and priority is NULL.
+            $selectduplicates = "id != :eventid
+                                 AND courseid != :courseid
+                                 AND groupid = 0
+                                 AND userid = :userid
+                                 AND repeatid = :repeatid
+                                 AND modulename = :modulename
+                                 AND type = :type
+                                 AND eventtype = :eventtype
+                                 AND timestart = :timestart
+                                 AND timeduration = :timeduration
+                                 AND timesort = :timesort
+                                 AND sequence = :sequence
+                                 AND priority IS NULL";
+            $paramsduplicates = [
+                'eventid' => $groupevent->id,
+                'courseid' => $groupevent->courseid,
+                'groupid' => 0,
+                'userid' => $groupevent->userid,
+                'repeatid' => $groupevent->repeatid,
+                'modulename' => $groupevent->modulename,
+                'type' => $groupevent->type,
+                'eventtype' => $groupevent->eventtype,
+                'timestart' => $groupevent->timestart,
+                'timeduration' => $groupevent->timeduration,
+                'timesort' => $groupevent->timesort,
+                'sequence' => $groupevent->sequence
+            ];
+            $DB->delete_records_select('event', $selectduplicates, $paramsduplicates);
+        }
+    }
+}

mod/assign/version.php

@@ -25,6 +25,6 @@
 defined('MOODLE_INTERNAL') || die();
 
 $plugin->component = 'mod_assign'; // Full name of the plugin (used for diagnostics).
-$plugin->version  = 2018051400;    // The current module version (Date: YYYYMMDDXX).
+$plugin->version  = 2018061100;    // The current module version (Date: YYYYMMDDXX).
 $plugin->requires = 2018050800;    // Requires this Moodle version.
 $plugin->cron     = 60;