From 5c0b5ba57506c6f78ff6021b31c67ee698099624 Mon Sep 17 00:00:00 2001
From: Tim Hunt <T.J.Hunt@open.ac.uk>
Date: Wed, 22 Jan 2014 12:45:08 +0000
Subject: [PATCH] MDL-43809 qformat_xml messes up $s in multianswer questions.

---
 question/format/xml/format.php               |  2 +-
 question/format/xml/tests/xmlformat_test.php | 25 +++++++++
 question/type/multianswer/tests/helper.php   | 59 +++++++++++++++++++-
 3 files changed, 84 insertions(+), 2 deletions(-)

diff --git a/question/format/xml/format.php b/question/format/xml/format.php
index 43c17e03df6..df9e6094bbe 100644
--- a/question/format/xml/format.php
+++ b/question/format/xml/format.php
@@ -1270,7 +1270,7 @@ class qformat_xml extends qformat_default {
 
             case 'multianswer':
                 foreach ($question->options->questions as $index => $subq) {
-                    $expout = preg_replace('~{#' . $index . '}~', $subq->questiontext, $expout);
+                    $expout = str_replace('{#' . $index . '}', $subq->questiontext, $expout);
                 }
                 break;
 
diff --git a/question/format/xml/tests/xmlformat_test.php b/question/format/xml/tests/xmlformat_test.php
index 448cc279370..8396838b0d4 100644
--- a/question/format/xml/tests/xmlformat_test.php
+++ b/question/format/xml/tests/xmlformat_test.php
@@ -1423,6 +1423,31 @@ END;
         $this->assert_same_xml($expectedxml, $xml);
     }
 
+    public function test_export_multianswer_withdollars() {
+        $qdata = test_question_maker::get_question_data('multianswer', 'dollarsigns');
+
+        $exporter = new qformat_xml();
+        $xml = $exporter->writequestion($qdata);
+
+        $expectedxml = '<!-- question: 0  -->
+  <question type="cloze">
+    <name>
+      <text>Multianswer with $s</text>
+    </name>
+    <questiontext format="html">
+      <text>Which is the right order? {1:MULTICHOICE:=y,y,$3~$3,y,y}</text>
+    </questiontext>
+    <generalfeedback format="html">
+      <text></text>
+    </generalfeedback>
+    <penalty>0.3333333</penalty>
+    <hidden>0</hidden>
+  </question>
+';
+
+        $this->assert_same_xml($expectedxml, $xml);
+    }
+
     public function test_import_files_as_draft() {
         $this->resetAfterTest();
         $this->setAdminUser();
diff --git a/question/type/multianswer/tests/helper.php b/question/type/multianswer/tests/helper.php
index 92a51e489be..7c40776ee01 100644
--- a/question/type/multianswer/tests/helper.php
+++ b/question/type/multianswer/tests/helper.php
@@ -37,7 +37,7 @@ require_once($CFG->dirroot . '/question/type/multianswer/question.php');
  */
 class qtype_multianswer_test_helper extends question_test_helper {
     public function get_test_questions() {
-        return array('twosubq', 'fourmc', 'numericalzero');
+        return array('twosubq', 'fourmc', 'numericalzero', 'dollarsigns');
     }
 
     /**
@@ -196,6 +196,63 @@ class qtype_multianswer_test_helper extends question_test_helper {
         return $qdata;
     }
 
+    /**
+     * Makes a multianswer question onetaining one blank in some text.
+     * This question has no hints.
+     *
+     * @return object the question definition data, as it might be returned from
+     * get_question_options.
+     */
+    public function get_multianswer_question_data_dollarsigns() {
+        $qdata = new stdClass();
+        test_question_maker::initialise_question_data($qdata);
+
+        $qdata->name = 'Multianswer with $s';
+        $qdata->questiontext =
+                        'Which is the right order? {#1}';
+        $qdata->generalfeedback = '';
+
+        $qdata->defaultmark = 1.0;
+        $qdata->qtype = 'multianswer';
+
+        $mc = new stdClass();
+        test_question_maker::initialise_question_data($mc);
+
+        $mc->name = 'Multianswer with $s';
+        $mc->questiontext = '{1:MULTICHOICE:=y,y,$3~$3,y,y}';
+        $mc->generalfeedback = '';
+        $mc->penalty = 0.0;
+        $mc->qtype = 'multichoice';
+
+        $mc->options = new stdClass();
+        $mc->options->layout = 0;
+        $mc->options->single = 1;
+        $mc->options->shuffleanswers = 1;
+        $mc->options->correctfeedback = '';
+        $mc->options->correctfeedbackformat = 1;
+        $mc->options->partiallycorrectfeedback = '';
+        $mc->options->partiallycorrectfeedbackformat = 1;
+        $mc->options->incorrectfeedback = '';
+        $mc->options->incorrectfeedbackformat = 1;
+        $mc->options->answernumbering = 0;
+        $mc->options->shownumcorrect = 0;
+
+        $mc->options->answers = array(
+            23 => new question_answer(23, 'y,y,$3', 0, '', FORMAT_HTML),
+            24 => new question_answer(24, '$3,y,y', 0, '', FORMAT_HTML),
+        );
+
+        $qdata->options = new stdClass();
+        $qdata->options->questions = array(
+            1 => $mc,
+        );
+
+        $qdata->hints = array(
+        );
+
+        return $qdata;
+    }
+
     /**
      * Makes a multianswer question about completing two blanks in some text.
      * @return object the question definition data, as it might be returned from