From 4fddeb50953d0842f7b16c0298b346ddbe9f2c57 Mon Sep 17 00:00:00 2001
From: Angel Fernando Quiroz Campos <angelfqc.18@gmail.com>
Date: Thu, 29 Oct 2015 09:39:17 -0500
Subject: [PATCH] Fix survey already answered by anonymous users - res BT#10490

---
 main/survey/fillsurvey.php | 12 ++++++++--
 main/survey/survey.lib.php | 47 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/main/survey/fillsurvey.php b/main/survey/fillsurvey.php
index 10ca6b92e4..eb301be6c8 100755
--- a/main/survey/fillsurvey.php
+++ b/main/survey/fillsurvey.php
@@ -141,8 +141,13 @@ if (Database::num_rows($result) < 1) {
 $survey_invitation = Database::fetch_array($result, 'ASSOC');
 
 // Now we check if the user already filled the survey
-if ( !isset($_POST['finish_survey']) &&
-    ($isAnonymous && isset($_SESSION['surveyuser'])) ||
+if (
+    !isset($_POST['finish_survey']) &&
+    (
+        $isAnonymous &&
+        isset($_SESSION['surveyuser']) &&
+        SurveyUtil::isSurveyAnsweredFlagged($survey_invitation['survey_code'], $survey_invitation['c_id'])
+    ) ||
     ($survey_invitation['answered'] == 1 && !isset($_GET['user_id']))
 ) {
     Display :: display_error_message(get_lang('YouAlreadyFilledThisSurvey'), false);
@@ -523,6 +528,9 @@ if (isset($_POST['finish_survey'])) {
         $survey_invitation['user'],
         $survey_invitation['survey_code']
     );
+
+    SurveyUtil::flagSurveyAsAnswered($survey_invitation['survey_code'], $survey_invitation['c_id']);
+
     unset($_SESSION['paged_questions']);
     unset($_SESSION['page_questions_sec']);
     Display :: display_footer();
diff --git a/main/survey/survey.lib.php b/main/survey/survey.lib.php
index 35003193d4..6863a8581d 100755
--- a/main/survey/survey.lib.php
+++ b/main/survey/survey.lib.php
@@ -5190,4 +5190,51 @@ class SurveyUtil
             return false;
         }
     }
+
+    /**
+     * Set a flag to the current survey as answered by the current user
+     * @param string $surveyCode The survey code
+     * @param int $courseId The course ID
+     */
+    public static function flagSurveyAsAnswered($surveyCode, $courseId)
+    {
+        $currenUserId = api_get_user_id();
+        $flag = sprintf("%s-%s-%d", $courseId, $surveyCode, $currenUserId);
+
+        if (!isset($_SESSION['filled_surveys'])) {
+            $_SESSION['filled_surveys'] = array();
+        }
+
+        $_SESSION['filled_surveys'][] = $flag;
+    }
+
+    /**
+     * Check whether a survey was answered by the current user
+     * @param string $surveyCode The survey code
+     * @param int $courseId The course ID
+     * @return boolean
+     */
+    public static function isSurveyAnsweredFlagged($surveyCode, $courseId)
+    {
+        $currenUserId = api_get_user_id();
+        $flagToCheck = sprintf("%s-%s-%d", $courseId, $surveyCode, $currenUserId);
+
+        if (!isset($_SESSION['filled_surveys'])) {
+            return false;
+        }
+
+        if (!is_array($_SESSION['filled_surveys'])) {
+            return false;
+        }
+
+        foreach ($_SESSION['filled_surveys'] as $flag) {
+            if ($flagToCheck != $flag) {
+                continue;
+            }
+
+            return true;
+        }
+
+        return false;
+    }
 }