allow `|` in cloze_exercise, re #138

exercises/cloze_exercise.php

@@ -369,7 +369,7 @@ class cloze_exercise extends Exercise
                 foreach ($this->task['answers'][$blank] as $answer) {
                     $answer_text = $answer['text'];
 
-                    if (preg_match('/^([":*~]|$)/', $answer_text)) {
+                    if (preg_match('/^([":*~]|$|.*\|)/', $answer_text)) {
                         $answer_text = '"' . $answer_text . '"';
                     }
 
@@ -424,7 +424,9 @@ class cloze_exercise extends Exercise
                 }
 
                 if ($part !== '') {
-                    foreach (explode('|', $part) as $answer) {
+                    preg_match_all('/( *[*~]?".*?" *|[^|]*)\|/', $part . '|', $matches);
+
+                    foreach ($matches[1] as $answer) {
                         $answer = trim($answer);
                         $points = 1;