MDL-34532 quiz reports: error when showing users without attempts.

We were not checking if attempt state was null before trying to convert it to a string.

diff --git a/mod/quiz/report/attemptsreport_table.php b/mod/quiz/report/attemptsreport_table.php
index 4334256..f119da0 100644 (file)
--- a/mod/quiz/report/attemptsreport_table.php
+++ b/mod/quiz/report/attemptsreport_table.php
@@ -152,7 +152,11 @@ abstract class quiz_attempts_report_table extends table_sql {
      * @return string HTML content to go inside the td.
      */
     public function col_state($attempt) {
-        return quiz_attempt::state_name($attempt->state);
+        if (!is_null($attempt->attempt)) {
+            return quiz_attempt::state_name($attempt->state);
+        } else {
+            return  '-';
+        }
     }
 
     /**