From c34e48187168301d2b00f2be2c603854dcc87d4a Mon Sep 17 00:00:00 2001
From: Julio Montoya <gugli100@gmail.com>
Date: Fri, 30 Nov 2018 11:52:50 +0100
Subject: [PATCH] Fix session course redirection

Checking the visibility and visibility priority:

SESSION_AVAILABLE,
SESSION_VISIBLE
SESSION_VISIBLE_READ_ONLY

If the user is subscribed in different sessions with the same course

See BT#12083 BT#15106
---
 main/inc/local.inc.php | 71 ++++++++++++++++++++++++++++++------------
 1 file changed, 51 insertions(+), 20 deletions(-)

diff --git a/main/inc/local.inc.php b/main/inc/local.inc.php
index cec8fbfa49..5836aa0245 100755
--- a/main/inc/local.inc.php
+++ b/main/inc/local.inc.php
@@ -1358,29 +1358,60 @@ if ((isset($uidReset) && $uidReset) || $cidReset) {
                     $_course['real_id']
                 );
 
-                if (!empty($courseSession) && isset($courseSession[0])) {
-                    $courseSessionItem = $courseSession[0];
-                    if (isset($courseSessionItem['session_id'])) {
-                        $customSessionId = $courseSessionItem['session_id'];
-                        $currentUrl = htmlentities($_SERVER['REQUEST_URI']);
-                        $currentUrl = str_replace('id_session=0', '', $currentUrl);
-                        $currentUrl = str_replace('&amp;', '&', $currentUrl);
-
-                        if (strpos($currentUrl, '?') !== false) {
-                            $currentUrl = rtrim($currentUrl, '&');
-                            $url = $currentUrl.'&id_session='.$customSessionId;
-                        } else {
-                            $url = $currentUrl.'?id_session='.$customSessionId;
+
+                $priorityList = [];
+                if (!empty($courseSession)) {
+                    foreach ($courseSession as $courseSessionItem) {
+                        if (isset($courseSessionItem['session_id'])) {
+                            $customSessionId = $courseSessionItem['session_id'];
+                            $visibility = api_get_session_visibility($customSessionId, $_course['real_id']);
+
+                            if ($visibility == SESSION_INVISIBLE) {
+                                continue;
+                            }
+
+                            switch ($visibility) {
+                                case SESSION_AVAILABLE:
+                                    $priorityList[1][] = $customSessionId;
+                                    break;
+                                case SESSION_VISIBLE:
+                                    $priorityList[2][] = $customSessionId;
+                                    break;
+                                case SESSION_VISIBLE_READ_ONLY:
+                                    $priorityList[3][] = $customSessionId;
+                                    break;
+                            }
                         }
-                        $url = str_replace('&&', '&', $url);
-                        //$url = $_course['course_public_url'].'?id_session='.$customSessionId;
+                    }
+                }
 
-                        Session::erase('_real_cid');
-                        Session::erase('_cid');
-                        Session::erase('_course');
+                if (!empty($priorityList)) {
+                    ksort($priorityList);
+                    foreach ($priorityList as $sessionList) {
+                        if (empty($sessionList)) {
+                            continue;
+                        }
+                        foreach ($sessionList as $customSessionId) {
+                            $currentUrl = htmlentities($_SERVER['REQUEST_URI']);
+                            $currentUrl = str_replace('id_session=0', '', $currentUrl);
+                            $currentUrl = str_replace('&amp;', '&', $currentUrl);
+
+                            if (strpos($currentUrl, '?') !== false) {
+                                $currentUrl = rtrim($currentUrl, '&');
+                                $url = $currentUrl.'&id_session='.$customSessionId;
+                            } else {
+                                $url = $currentUrl.'?id_session='.$customSessionId;
+                            }
+                            $url = str_replace('&&', '&', $url);
+                            //$url = $_course['course_public_url'].'?id_session='.$customSessionId;
 
-                        header('Location: '.$url);
-                        exit;
+                            Session::erase('_real_cid');
+                            Session::erase('_cid');
+                            Session::erase('_course');
+
+                            header('Location: '.$url);
+                            exit;
+                        }
                     }
                 }
             }