MDL-66273 qtype_random: Fix question deletion during course restore

question/type/random/classes/task/remove_unused_questions.php

@@ -25,6 +25,8 @@
 
 namespace qtype_random\task;
 
+use core\task\manager;
+
 defined('MOODLE_INTERNAL') || die();
 
 
@@ -44,6 +46,21 @@ class remove_unused_questions extends \core\task\scheduled_task {
         global $DB, $CFG;
         require_once($CFG->libdir . '/questionlib.php');
 
+        // Confirm, that there is no restore in progress to make sure we do not
+        // clean up questions that have their quiz slots not restored yet.
+        $restoretasks = [
+            '\core\task\asynchronous_copy_task',
+            '\core\task\asynchronous_restore_task',
+        ];
+
+        $running = manager::get_running_tasks();
+        foreach ($running as $task) {
+            if (in_array($task->classname, $restoretasks)) {
+                mtrace('Detected running async restore. Aborting the task.');
+                return;
+            }
+        }
+
         // Find potentially unused random questions (up to 10000).
         // Note, because we call question_delete_question below,
         // the question will not actually be deleted if something else

question/type/random/tests/cleanup_task_test.php

@@ -67,4 +67,37 @@ class qtype_random_cleanup_task_testcase extends advanced_testcase {
         $this->assertTrue($DB->record_exists('question', ['id' => $quizslots[1]->questionid]));
         $this->assertFalse($DB->record_exists('question', ['id' => $quizslots[2]->questionid]));
     }
+
+    /**
+     * Test that remove_unused_questions aborts when there is a course restore in progress.
+     */
+    public function test_cleanup_task_checks_for_active_restores() {
+        $this->resetAfterTest();
+
+        // Get ready the tasks.
+        $cleanuptask = new \qtype_random\task\remove_unused_questions();
+        $restoretask = new \core\task\asynchronous_restore_task();
+        \core\task\manager::queue_adhoc_task($restoretask);
+        $copytask = new \core\task\asynchronous_copy_task();
+        \core\task\manager::queue_adhoc_task($copytask);
+
+        // Start the first adhoc task. This might be either restore or copy adhoc task.
+        $task1 = \core\task\manager::get_next_adhoc_task(time());
+        \core\task\manager::adhoc_task_starting($task1);
+        $cleanuptask->execute();
+
+        // Complete the first task and start the second one.
+        \core\task\manager::adhoc_task_complete($task1);
+        $task2 = \core\task\manager::get_next_adhoc_task(time());
+        \core\task\manager::adhoc_task_starting($task2);
+        $cleanuptask->execute();
+
+        // Complete the second adhoc task.
+        \core\task\manager::adhoc_task_complete($task2);
+        $cleanuptask->execute();
+
+        $aborted = 'Detected running async restore. Aborting the task.';
+        $completed = 'Cleaned up 0 unused random questions.';
+        $this->expectOutputRegex("/.*$aborted.*\s.*$aborted.*\s.*$completed.*/");
+    }
 }