From 19f2b2a41f5b603c5d996855830d00ff76dbf0da Mon Sep 17 00:00:00 2001
From: Damyon Wiese <damyon@moodle.com>
Date: Thu, 18 Jul 2013 16:45:44 +0800
Subject: [PATCH] MDL-35851 lesson: Handle importing questions into an empty
 lesson.

Also - make sure the page we are updating belongs to the lesson.
---
 mod/lesson/format.php | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/mod/lesson/format.php b/mod/lesson/format.php
index f2f4979c6a7..a6a5dc4f1fd 100644
--- a/mod/lesson/format.php
+++ b/mod/lesson/format.php
@@ -328,7 +328,7 @@ class qformat_default {
             $addquestionontop = true;
             $updatelessonpage = $DB->get_record('lesson_pages', array('lessonid' => $lesson->id, 'prevpageid' => 0));
         } else {
-            $updatelessonpage = $DB->get_record('lesson_pages', array('id' => $pageid));
+            $updatelessonpage = $DB->get_record('lesson_pages', array('lessonid' => $lesson->id, 'id' => $pageid));
         }
 
         $unsupportedquestions = 0;
@@ -432,11 +432,13 @@ class qformat_default {
                     break;
             }
         }
-        // update the prev links
-        if ($addquestionontop) {
-            $DB->set_field("lesson_pages", "prevpageid", $pageid, array("id" => $updatelessonpage->id));
-        } else {
-            $DB->set_field("lesson_pages", "prevpageid", $pageid, array("id" => $updatelessonpage->nextpageid));
+        // Update the prev links if there were existing pages.
+        if (!empty($updatelessonpage)) {
+            if ($addquestionontop) {
+                $DB->set_field("lesson_pages", "prevpageid", $pageid, array("id" => $updatelessonpage->id));
+            } else {
+                $DB->set_field("lesson_pages", "prevpageid", $pageid, array("id" => $updatelessonpage->nextpageid));
+            }
         }
         if ($unsupportedquestions) {
             echo $OUTPUT->notification(get_string('unknownqtypesnotimported', 'lesson', $unsupportedquestions));