diff --git a/mod/forum/discuss.php b/mod/forum/discuss.php
index d5fed0bfd60..0fd6e771a41 100644
--- a/mod/forum/discuss.php
+++ b/mod/forum/discuss.php
@@ -266,7 +266,7 @@ if (!$canreply and $forum->type !== 'news') {
 }
 
 // Output the links to neighbour discussions.
-$neighbours = forum_get_discussion_neighbours($cm, $discussion);
+$neighbours = forum_get_discussion_neighbours($cm, $discussion, $forum);
 $neighbourlinks = $renderer->neighbouring_discussion_navigation($neighbours['prev'], $neighbours['next']);
 echo $neighbourlinks;
 
diff --git a/mod/forum/lib.php b/mod/forum/lib.php
index 42f6db39301..8f1557c8e18 100644
--- a/mod/forum/lib.php
+++ b/mod/forum/lib.php
@@ -2704,20 +2704,24 @@ function forum_get_discussions($cm, $forumsort="d.timemodified DESC", $fullpost=
  * other mean to sort the records, e.g. we cannot use IDs as a greater ID can have a lower
  * timemodified.
  *
+ * For blog-style forums, the calculation is based on the original creation time of the
+ * blog post.
+ *
  * Please note that this does not check whether or not the discussion passed is accessible
  * by the user, it simply uses it as a reference to find the neighbours. On the other hand,
  * the returned neighbours are checked and are accessible to the current user.
  *
  * @param object $cm The CM record.
  * @param object $discussion The discussion record.
+ * @param object $forum The forum instance record.
  * @return array That always contains the keys 'prev' and 'next'. When there is a result
  *               they contain the record with minimal information such as 'id' and 'name'.
  *               When the neighbour is not found the value is false.
  */
-function forum_get_discussion_neighbours($cm, $discussion) {
+function forum_get_discussion_neighbours($cm, $discussion, $forum) {
     global $CFG, $DB, $USER;
 
-    if ($cm->instance != $discussion->forum) {
+    if ($cm->instance != $discussion->forum or $discussion->forum != $forum->id or $forum->id != $cm->instance) {
         throw new coding_exception('Discussion is not part of the same forum.');
     }
 
@@ -2762,25 +2766,54 @@ function forum_get_discussion_neighbours($cm, $discussion) {
         }
     }
 
-    $params['forumid'] = $cm->instance;
-    $params['discid'] = $discussion->id;
-    $params['disctimemodified'] = $discussion->timemodified;
+    if ($forum->type === 'blog') {
+        $params['forumid'] = $cm->instance;
+        $params['discid1'] = $discussion->id;
+        $params['discid2'] = $discussion->id;
 
-    $sql = "SELECT d.id, d.name, d.timemodified, d.groupid, d.timestart, d.timeend
-              FROM {forum_discussions} d
-             WHERE d.forum = :forumid
-               AND d.id <> :discid
-                   $timelimit
-                   $groupselect";
+        $sql = "SELECT d.id, d.name, d.timemodified, d.groupid, d.timestart, d.timeend
+                  FROM {forum_discussions} d
+                  JOIN {forum_posts} p ON d.firstpost = p.id
+                 WHERE d.forum = :forumid
+                   AND d.id <> :discid1
+                       $timelimit
+                       $groupselect";
 
-    $prevsql = $sql . " AND d.timemodified < :disctimemodified
-                   ORDER BY d.timemodified DESC";
+        $sub = "SELECT pp.created
+                  FROM {forum_discussions} dd
+                  JOIN {forum_posts} pp ON dd.firstpost = pp.id
+                 WHERE dd.id = :discid2";
 
-    $nextsql = $sql . " AND d.timemodified > :disctimemodified
-                   ORDER BY d.timemodified ASC";
+        $prevsql = $sql . " AND p.created < ($sub)
+                       ORDER BY p.created DESC";
 
-    $neighbours['prev'] = $DB->get_record_sql($prevsql, $params, IGNORE_MULTIPLE);
-    $neighbours['next'] = $DB->get_record_sql($nextsql, $params, IGNORE_MULTIPLE);
+        $nextsql = $sql . " AND p.created > ($sub)
+                       ORDER BY p.created ASC";
+
+        $neighbours['prev'] = $DB->get_record_sql($prevsql, $params, IGNORE_MULTIPLE);
+        $neighbours['next'] = $DB->get_record_sql($nextsql, $params, IGNORE_MULTIPLE);
+
+    } else {
+        $params['forumid'] = $cm->instance;
+        $params['discid'] = $discussion->id;
+        $params['disctimemodified'] = $discussion->timemodified;
+
+        $sql = "SELECT d.id, d.name, d.timemodified, d.groupid, d.timestart, d.timeend
+                  FROM {forum_discussions} d
+                 WHERE d.forum = :forumid
+                   AND d.id <> :discid
+                       $timelimit
+                       $groupselect";
+
+        $prevsql = $sql . " AND d.timemodified < :disctimemodified
+                       ORDER BY d.timemodified DESC";
+
+        $nextsql = $sql . " AND d.timemodified > :disctimemodified
+                       ORDER BY d.timemodified ASC";
+
+        $neighbours['prev'] = $DB->get_record_sql($prevsql, $params, IGNORE_MULTIPLE);
+        $neighbours['next'] = $DB->get_record_sql($nextsql, $params, IGNORE_MULTIPLE);
+    }
 
     return $neighbours;
 }
diff --git a/mod/forum/tests/behat/posts_ordering_blog.feature b/mod/forum/tests/behat/posts_ordering_blog.feature
new file mode 100644
index 00000000000..8d08a9d4fd0
--- /dev/null
+++ b/mod/forum/tests/behat/posts_ordering_blog.feature
@@ -0,0 +1,87 @@
+@mod @mod_forum
+Feature: Blog posts are always displayed in reverse chronological order
+  In order to use forum as a blog
+  As a user
+  I need to see most recent blog posts first
+
+  Background:
+    Given the following "users" exist:
+      | username  | firstname | lastname  | email                 |
+      | teacher1  | Teacher   | 1         | teacher1@example.com  |
+      | student1  | Student   | 1         | student1@example.com  |
+    And the following "courses" exist:
+      | fullname  | shortname | category  |
+      | Course 1  | C1        | 0         |
+    And the following "course enrolments" exist:
+      | user      | course    | role            |
+      | teacher1  | C1        | editingteacher  |
+      | student1  | C1        | student         |
+    And I log in as "teacher1"
+    And I follow "Course 1"
+    And I turn editing mode on
+    And I add a "Forum" to section "1" and I fill the form with:
+      | Forum name  | Course blog forum                               |
+      | Description | Single discussion forum description             |
+      | Forum type  | Standard forum displayed in a blog-like format  |
+    And I log out
+
+  #
+  # We need javascript/wait to prevent creation of the posts in the same second. The threads
+  # would then ignore each other in the prev/next navigation as the Forum is unable to compute
+  # the correct order.
+  #
+  @javascript
+  Scenario: Replying to a blog post or editing it does not affect its display order
+    Given I log in as "student1"
+    And I follow "Course 1"
+    And I follow "Course blog forum"
+    #
+    # Add three posts into the blog.
+    #
+    When I add a new topic to "Course blog forum" forum with:
+      | Subject | Blog post 1             |
+      | Message | This is the first post  |
+    And I wait "1" seconds
+    And I add a new topic to "Course blog forum" forum with:
+      | Subject | Blog post 2             |
+      | Message | This is the second post |
+    And I wait "1" seconds
+    And I add a new topic to "Course blog forum" forum with:
+      | Subject | Blog post 3             |
+      | Message | This is the third post  |
+    #
+    # Edit one of the blog posts.
+    #
+    And I click on "Edit" "link" in the "//div[@aria-label='Blog post 2 by Student 1']" "xpath_element"
+    And I set the following fields to these values:
+      | Subject | Edited blog post 2      |
+    And I press "Save changes"
+    And I wait to be redirected
+    And I log out
+    #
+    # Reply to another blog post.
+    #
+    And I log in as "teacher1"
+    And I follow "Course 1"
+    And I follow "Course blog forum"
+    And I click on "Discuss this topic" "link" in the "//div[@aria-label='Blog post 1 by Student 1']" "xpath_element"
+    And I click on "Reply" "link" in the "//div[@aria-label='Blog post 1 by Student 1']" "xpath_element"
+    And I set the following fields to these values:
+      | Message | Reply to the first post |
+    And I press "Post to forum"
+    And I wait to be redirected
+    And I am on site homepage
+    And I follow "Course 1"
+    And I follow "Course blog forum"
+    #
+    # Make sure the order of the blog posts is still reverse chronological.
+    #
+    Then I should see "This is the third post" in the "//div[contains(concat(' ', normalize-space(@class), ' '), ' forumpost ')][position()=1]" "xpath_element"
+    And I should see "This is the second post" in the "//div[contains(concat(' ', normalize-space(@class), ' '), ' forumpost ')][position()=2]" "xpath_element"
+    And I should see "This is the first post" in the "//div[contains(concat(' ', normalize-space(@class), ' '), ' forumpost ')][position()=3]" "xpath_element"
+    #
+    # Make sure the next/prev navigation uses the same order of the posts.
+    #
+    And I click on "Discuss this topic" "link" in the "//div[@aria-label='Edited blog post 2 by Student 1']" "xpath_element"
+    And "//a[@aria-label='Next discussion: Blog post 3']" "xpath_element" should exist
+    And "//a[@aria-label='Previous discussion: Blog post 1']" "xpath_element" should exist
diff --git a/mod/forum/tests/behat/posts_ordering_general.feature b/mod/forum/tests/behat/posts_ordering_general.feature
new file mode 100644
index 00000000000..cf5df8aabf7
--- /dev/null
+++ b/mod/forum/tests/behat/posts_ordering_general.feature
@@ -0,0 +1,88 @@
+@mod @mod_forum
+Feature: New discussions and discussions with recently added replies are displayed first
+  In order to use forum as a discussion tool
+  As a user
+  I need to see currently active discussions first
+
+  Background:
+    Given the following "users" exist:
+      | username  | firstname | lastname  | email                 |
+      | teacher1  | Teacher   | 1         | teacher1@example.com  |
+      | student1  | Student   | 1         | student1@example.com  |
+    And the following "courses" exist:
+      | fullname  | shortname | category  |
+      | Course 1  | C1        | 0         |
+    And the following "course enrolments" exist:
+      | user      | course    | role            |
+      | teacher1  | C1        | editingteacher  |
+      | student1  | C1        | student         |
+    And I log in as "teacher1"
+    And I follow "Course 1"
+    And I turn editing mode on
+    And I add a "Forum" to section "1" and I fill the form with:
+      | Forum name  | Course general forum                |
+      | Description | Single discussion forum description |
+      | Forum type  | Standard forum for general use      |
+    And I log out
+
+  #
+  # We need javascript/wait to prevent creation of the posts in the same second. The threads
+  # would then ignore each other in the prev/next navigation as the Forum is unable to compute
+  # the correct order.
+  #
+  @javascript
+  Scenario: Replying to a forum post or editing it puts the discussion to the front
+    Given I log in as "student1"
+    And I follow "Course 1"
+    And I follow "Course general forum"
+    #
+    # Add three posts into the forum.
+    #
+    When I add a new discussion to "Course general forum" forum with:
+      | Subject | Forum post 1            |
+      | Message | This is the first post  |
+    And I wait "1" seconds
+    And I add a new discussion to "Course general forum" forum with:
+      | Subject | Forum post 2            |
+      | Message | This is the second post |
+    And I wait "1" seconds
+    And I add a new discussion to "Course general forum" forum with:
+      | Subject | Forum post 3            |
+      | Message | This is the third post  |
+    #
+    # Edit one of the forum posts.
+    #
+    And I follow "Forum post 2"
+    And I click on "Edit" "link" in the "//div[contains(concat(' ', normalize-space(@class), ' '), ' forumpost ')][contains(., 'Forum post 2')]" "xpath_element"
+    And I set the following fields to these values:
+      | Subject | Edited forum post 2     |
+    And I press "Save changes"
+    And I wait to be redirected
+    And I log out
+    #
+    # Reply to another forum post.
+    #
+    And I log in as "teacher1"
+    And I follow "Course 1"
+    And I follow "Course general forum"
+    And I follow "Forum post 1"
+    And I click on "Reply" "link" in the "//div[@aria-label='Forum post 1 by Student 1']" "xpath_element"
+    And I set the following fields to these values:
+      | Message | Reply to the first post |
+    And I press "Post to forum"
+    And I wait to be redirected
+    And I am on site homepage
+    And I follow "Course 1"
+    And I follow "Course general forum"
+    #
+    # Make sure the order of the forum posts is as expected (most recently participated first).
+    #
+    Then I should see "Forum post 3" in the "//tr[contains(concat(' ', normalize-space(@class), ' '), ' discussion ')][position()=3]" "xpath_element"
+    And I should see "Edited forum post 2" in the "//tr[contains(concat(' ', normalize-space(@class), ' '), ' discussion ')][position()=2]" "xpath_element"
+    And I should see "Forum post 1" in the "//tr[contains(concat(' ', normalize-space(@class), ' '), ' discussion ')][position()=1]" "xpath_element"
+    #
+    # Make sure the next/prev navigation uses the same order of the posts.
+    #
+    And I follow "Edited forum post 2"
+    And "//a[@aria-label='Next discussion: Forum post 1']" "xpath_element" should exist
+    And "//a[@aria-label='Previous discussion: Forum post 3']" "xpath_element" should exist
diff --git a/mod/forum/tests/lib_test.php b/mod/forum/tests/lib_test.php
index bc38397c8e7..d427c85c2da 100644
--- a/mod/forum/tests/lib_test.php
+++ b/mod/forum/tests/lib_test.php
@@ -822,23 +822,23 @@ class mod_forum_lib_testcase extends advanced_testcase {
         $disc5 = $forumgen->create_discussion($record);
 
         // Getting the neighbours.
-        $neighbours = forum_get_discussion_neighbours($cm, $disc1);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc1, $forum);
         $this->assertEmpty($neighbours['prev']);
         $this->assertEquals($disc2->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm, $disc2);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc2, $forum);
         $this->assertEquals($disc1->id, $neighbours['prev']->id);
         $this->assertEquals($disc3->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm, $disc3);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc3, $forum);
         $this->assertEquals($disc2->id, $neighbours['prev']->id);
         $this->assertEquals($disc4->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm, $disc4);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc4, $forum);
         $this->assertEquals($disc3->id, $neighbours['prev']->id);
         $this->assertEquals($disc5->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm, $disc5);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc5, $forum);
         $this->assertEquals($disc4->id, $neighbours['prev']->id);
         $this->assertEmpty($neighbours['next']);
 
@@ -848,28 +848,28 @@ class mod_forum_lib_testcase extends advanced_testcase {
         $disc1->timemodified = time();
         $DB->update_record('forum_discussions', $disc1);
 
-        $neighbours = forum_get_discussion_neighbours($cm, $disc5);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc5, $forum);
         $this->assertEquals($disc4->id, $neighbours['prev']->id);
         $this->assertEquals($disc1->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm, $disc2);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc2, $forum);
         $this->assertEmpty($neighbours['prev']);
         $this->assertEquals($disc3->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm, $disc1);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc1, $forum);
         $this->assertEquals($disc5->id, $neighbours['prev']->id);
         $this->assertEmpty($neighbours['next']);
 
         // After some discussions were created.
         sleep(1);
         $disc6 = $forumgen->create_discussion($record);
-        $neighbours = forum_get_discussion_neighbours($cm, $disc6);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc6, $forum);
         $this->assertEquals($disc1->id, $neighbours['prev']->id);
         $this->assertEmpty($neighbours['next']);
 
         sleep(1);
         $disc7 = $forumgen->create_discussion($record);
-        $neighbours = forum_get_discussion_neighbours($cm, $disc7);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc7, $forum);
         $this->assertEquals($disc6->id, $neighbours['prev']->id);
         $this->assertEmpty($neighbours['next']);
 
@@ -906,59 +906,59 @@ class mod_forum_lib_testcase extends advanced_testcase {
 
         // Admin user ignores the timed settings of discussions.
         $this->setAdminUser();
-        $neighbours = forum_get_discussion_neighbours($cm, $disc8);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc8, $forum);
         $this->assertEquals($disc7->id, $neighbours['prev']->id);
         $this->assertEquals($disc9->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm, $disc9);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc9, $forum);
         $this->assertEquals($disc8->id, $neighbours['prev']->id);
         $this->assertEquals($disc10->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm, $disc10);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc10, $forum);
         $this->assertEquals($disc9->id, $neighbours['prev']->id);
         $this->assertEquals($disc11->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm, $disc11);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc11, $forum);
         $this->assertEquals($disc10->id, $neighbours['prev']->id);
         $this->assertEquals($disc12->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm, $disc12);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc12, $forum);
         $this->assertEquals($disc11->id, $neighbours['prev']->id);
         $this->assertEmpty($neighbours['next']);
 
         // Normal user can see their own timed discussions.
         $this->setUser($user);
-        $neighbours = forum_get_discussion_neighbours($cm, $disc8);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc8, $forum);
         $this->assertEquals($disc7->id, $neighbours['prev']->id);
         $this->assertEquals($disc9->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm, $disc9);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc9, $forum);
         $this->assertEquals($disc8->id, $neighbours['prev']->id);
         $this->assertEquals($disc10->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm, $disc10);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc10, $forum);
         $this->assertEquals($disc9->id, $neighbours['prev']->id);
         $this->assertEquals($disc11->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm, $disc11);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc11, $forum);
         $this->assertEquals($disc10->id, $neighbours['prev']->id);
         $this->assertEquals($disc12->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm, $disc12);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc12, $forum);
         $this->assertEquals($disc11->id, $neighbours['prev']->id);
         $this->assertEmpty($neighbours['next']);
 
         // Normal user does not ignore timed settings.
         $this->setUser($user2);
-        $neighbours = forum_get_discussion_neighbours($cm, $disc8);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc8, $forum);
         $this->assertEquals($disc7->id, $neighbours['prev']->id);
         $this->assertEquals($disc10->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm, $disc10);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc10, $forum);
         $this->assertEquals($disc8->id, $neighbours['prev']->id);
         $this->assertEquals($disc12->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm, $disc12);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc12, $forum);
         $this->assertEquals($disc10->id, $neighbours['prev']->id);
         $this->assertEmpty($neighbours['next']);
 
@@ -974,11 +974,197 @@ class mod_forum_lib_testcase extends advanced_testcase {
         $disc2 = $DB->get_record('forum_discussions', array('id' => $disc2->id));
         $disc3 = $DB->get_record('forum_discussions', array('id' => $disc3->id));
 
-        $neighbours = forum_get_discussion_neighbours($cm, $disc2);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc2, $forum);
         $this->assertEquals($disc12->id, $neighbours['prev']->id);
         $this->assertEmpty($neighbours['next']);
 
-        $neighbours = forum_get_discussion_neighbours($cm, $disc3);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc3, $forum);
+        $this->assertEquals($disc12->id, $neighbours['prev']->id);
+        $this->assertEmpty($neighbours['next']);
+    }
+
+    /**
+     * Test getting the neighbour threads of a blog-like forum.
+     */
+    public function test_forum_get_neighbours_blog() {
+        global $CFG, $DB;
+        $this->resetAfterTest();
+
+        // Setup test data.
+        $forumgen = $this->getDataGenerator()->get_plugin_generator('mod_forum');
+        $course = $this->getDataGenerator()->create_course();
+        $user = $this->getDataGenerator()->create_user();
+        $user2 = $this->getDataGenerator()->create_user();
+
+        $forum = $this->getDataGenerator()->create_module('forum', array('course' => $course->id, 'type' => 'blog'));
+        $cm = get_coursemodule_from_instance('forum', $forum->id);
+        $context = context_module::instance($cm->id);
+
+        $record = new stdClass();
+        $record->course = $course->id;
+        $record->userid = $user->id;
+        $record->forum = $forum->id;
+        $disc1 = $forumgen->create_discussion($record);
+        sleep(1);
+        $disc2 = $forumgen->create_discussion($record);
+        sleep(1);
+        $disc3 = $forumgen->create_discussion($record);
+        sleep(1);
+        $disc4 = $forumgen->create_discussion($record);
+        sleep(1);
+        $disc5 = $forumgen->create_discussion($record);
+
+        // Getting the neighbours.
+        $neighbours = forum_get_discussion_neighbours($cm, $disc1, $forum);
+        $this->assertEmpty($neighbours['prev']);
+        $this->assertEquals($disc2->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm, $disc2, $forum);
+        $this->assertEquals($disc1->id, $neighbours['prev']->id);
+        $this->assertEquals($disc3->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm, $disc3, $forum);
+        $this->assertEquals($disc2->id, $neighbours['prev']->id);
+        $this->assertEquals($disc4->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm, $disc4, $forum);
+        $this->assertEquals($disc3->id, $neighbours['prev']->id);
+        $this->assertEquals($disc5->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm, $disc5, $forum);
+        $this->assertEquals($disc4->id, $neighbours['prev']->id);
+        $this->assertEmpty($neighbours['next']);
+
+        // Make sure that the thread's timemodified does not affect the order.
+        sleep(1);
+        $disc1->timemodified = time();
+        $DB->update_record('forum_discussions', $disc1);
+
+        $neighbours = forum_get_discussion_neighbours($cm, $disc1, $forum);
+        $this->assertEmpty($neighbours['prev']);
+        $this->assertEquals($disc2->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm, $disc2, $forum);
+        $this->assertEquals($disc1->id, $neighbours['prev']->id);
+        $this->assertEquals($disc3->id, $neighbours['next']->id);
+
+        // Add another blog post.
+        sleep(1);
+        $disc6 = $forumgen->create_discussion($record);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc6, $forum);
+        $this->assertEquals($disc5->id, $neighbours['prev']->id);
+        $this->assertEmpty($neighbours['next']);
+
+        sleep(1);
+        $disc7 = $forumgen->create_discussion($record);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc7, $forum);
+        $this->assertEquals($disc6->id, $neighbours['prev']->id);
+        $this->assertEmpty($neighbours['next']);
+
+        // Adding timed discussions.
+        $CFG->forum_enabletimedposts = true;
+        $now = time();
+        $past = $now - 60;
+        $future = $now + 60;
+
+        $record = new stdClass();
+        $record->course = $course->id;
+        $record->userid = $user->id;
+        $record->forum = $forum->id;
+        $record->timestart = $past;
+        $record->timeend = $future;
+        sleep(1);
+        $disc8 = $forumgen->create_discussion($record);
+        sleep(1);
+        $record->timestart = $future;
+        $record->timeend = 0;
+        $disc9 = $forumgen->create_discussion($record);
+        sleep(1);
+        $record->timestart = 0;
+        $record->timeend = 0;
+        $disc10 = $forumgen->create_discussion($record);
+        sleep(1);
+        $record->timestart = 0;
+        $record->timeend = $past;
+        $disc11 = $forumgen->create_discussion($record);
+        sleep(1);
+        $record->timestart = $past;
+        $record->timeend = $future;
+        $disc12 = $forumgen->create_discussion($record);
+
+        // Admin user ignores the timed settings of discussions.
+        $this->setAdminUser();
+        $neighbours = forum_get_discussion_neighbours($cm, $disc8, $forum);
+        $this->assertEquals($disc7->id, $neighbours['prev']->id);
+        $this->assertEquals($disc9->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm, $disc9, $forum);
+        $this->assertEquals($disc8->id, $neighbours['prev']->id);
+        $this->assertEquals($disc10->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm, $disc10, $forum);
+        $this->assertEquals($disc9->id, $neighbours['prev']->id);
+        $this->assertEquals($disc11->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm, $disc11, $forum);
+        $this->assertEquals($disc10->id, $neighbours['prev']->id);
+        $this->assertEquals($disc12->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm, $disc12, $forum);
+        $this->assertEquals($disc11->id, $neighbours['prev']->id);
+        $this->assertEmpty($neighbours['next']);
+
+        // Normal user can see their own timed discussions.
+        $this->setUser($user);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc8, $forum);
+        $this->assertEquals($disc7->id, $neighbours['prev']->id);
+        $this->assertEquals($disc9->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm, $disc9, $forum);
+        $this->assertEquals($disc8->id, $neighbours['prev']->id);
+        $this->assertEquals($disc10->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm, $disc10, $forum);
+        $this->assertEquals($disc9->id, $neighbours['prev']->id);
+        $this->assertEquals($disc11->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm, $disc11, $forum);
+        $this->assertEquals($disc10->id, $neighbours['prev']->id);
+        $this->assertEquals($disc12->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm, $disc12, $forum);
+        $this->assertEquals($disc11->id, $neighbours['prev']->id);
+        $this->assertEmpty($neighbours['next']);
+
+        // Normal user does not ignore timed settings.
+        $this->setUser($user2);
+        $neighbours = forum_get_discussion_neighbours($cm, $disc8, $forum);
+        $this->assertEquals($disc7->id, $neighbours['prev']->id);
+        $this->assertEquals($disc10->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm, $disc10, $forum);
+        $this->assertEquals($disc8->id, $neighbours['prev']->id);
+        $this->assertEquals($disc12->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm, $disc12, $forum);
+        $this->assertEquals($disc10->id, $neighbours['prev']->id);
+        $this->assertEmpty($neighbours['next']);
+
+        // Reset to normal mode.
+        $CFG->forum_enabletimedposts = false;
+        $this->setAdminUser();
+
+        // Two blog posts with identical creation time ignore each other.
+        sleep(1);
+        $now = time();
+        $DB->update_record('forum_posts', (object) array('id' => $disc2->firstpost, 'created' => $now));
+        $DB->update_record('forum_posts', (object) array('id' => $disc3->firstpost, 'created' => $now));
+
+        $neighbours = forum_get_discussion_neighbours($cm, $disc2, $forum);
+        $this->assertEquals($disc12->id, $neighbours['prev']->id);
+        $this->assertEmpty($neighbours['next']);
+
+        $neighbours = forum_get_discussion_neighbours($cm, $disc3, $forum);
         $this->assertEquals($disc12->id, $neighbours['prev']->id);
         $this->assertEmpty($neighbours['next']);
     }
@@ -1051,38 +1237,38 @@ class mod_forum_lib_testcase extends advanced_testcase {
 
         // Admin user can see all groups.
         $this->setAdminUser();
-        $neighbours = forum_get_discussion_neighbours($cm1, $disc11);
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc11, $forum1);
         $this->assertEmpty($neighbours['prev']);
         $this->assertEquals($disc12->id, $neighbours['next']->id);
-        $neighbours = forum_get_discussion_neighbours($cm2, $disc21);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc21, $forum2);
         $this->assertEmpty($neighbours['prev']);
         $this->assertEquals($disc22->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm1, $disc12);
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc12, $forum1);
         $this->assertEquals($disc11->id, $neighbours['prev']->id);
         $this->assertEquals($disc13->id, $neighbours['next']->id);
-        $neighbours = forum_get_discussion_neighbours($cm2, $disc22);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc22, $forum2);
         $this->assertEquals($disc21->id, $neighbours['prev']->id);
         $this->assertEquals($disc23->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm1, $disc13);
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc13, $forum1);
         $this->assertEquals($disc12->id, $neighbours['prev']->id);
         $this->assertEquals($disc14->id, $neighbours['next']->id);
-        $neighbours = forum_get_discussion_neighbours($cm2, $disc23);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc23, $forum2);
         $this->assertEquals($disc22->id, $neighbours['prev']->id);
         $this->assertEquals($disc24->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm1, $disc14);
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc14, $forum1);
         $this->assertEquals($disc13->id, $neighbours['prev']->id);
         $this->assertEquals($disc15->id, $neighbours['next']->id);
-        $neighbours = forum_get_discussion_neighbours($cm2, $disc24);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc24, $forum2);
         $this->assertEquals($disc23->id, $neighbours['prev']->id);
         $this->assertEquals($disc25->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm1, $disc15);
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc15, $forum1);
         $this->assertEquals($disc14->id, $neighbours['prev']->id);
         $this->assertEmpty($neighbours['next']);
-        $neighbours = forum_get_discussion_neighbours($cm2, $disc25);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc25, $forum2);
         $this->assertEquals($disc24->id, $neighbours['prev']->id);
         $this->assertEmpty($neighbours['next']);
 
@@ -1091,24 +1277,24 @@ class mod_forum_lib_testcase extends advanced_testcase {
         $this->assertEquals($group1->id, groups_get_activity_group($cm1, true));
         $this->assertEquals($group1->id, groups_get_activity_group($cm2, true));
 
-        $neighbours = forum_get_discussion_neighbours($cm1, $disc11);
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc11, $forum1);
         $this->assertEmpty($neighbours['prev']);
         $this->assertEquals($disc13->id, $neighbours['next']->id);
-        $neighbours = forum_get_discussion_neighbours($cm2, $disc21);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc21, $forum2);
         $this->assertEmpty($neighbours['prev']);
         $this->assertEquals($disc23->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm1, $disc13);
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc13, $forum1);
         $this->assertEquals($disc11->id, $neighbours['prev']->id);
         $this->assertEquals($disc15->id, $neighbours['next']->id);
-        $neighbours = forum_get_discussion_neighbours($cm2, $disc23);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc23, $forum2);
         $this->assertEquals($disc21->id, $neighbours['prev']->id);
         $this->assertEquals($disc25->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm1, $disc15);
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc15, $forum1);
         $this->assertEquals($disc13->id, $neighbours['prev']->id);
         $this->assertEmpty($neighbours['next']);
-        $neighbours = forum_get_discussion_neighbours($cm2, $disc25);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc25, $forum2);
         $this->assertEquals($disc23->id, $neighbours['prev']->id);
         $this->assertEmpty($neighbours['next']);
 
@@ -1118,10 +1304,10 @@ class mod_forum_lib_testcase extends advanced_testcase {
         $this->assertEquals(0, groups_get_activity_group($cm1, true));
 
         // They can see anything in visible groups.
-        $neighbours = forum_get_discussion_neighbours($cm1, $disc12);
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc12, $forum1);
         $this->assertEquals($disc11->id, $neighbours['prev']->id);
         $this->assertEquals($disc13->id, $neighbours['next']->id);
-        $neighbours = forum_get_discussion_neighbours($cm1, $disc13);
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc13, $forum1);
         $this->assertEquals($disc12->id, $neighbours['prev']->id);
         $this->assertEquals($disc14->id, $neighbours['next']->id);
 
@@ -1130,15 +1316,15 @@ class mod_forum_lib_testcase extends advanced_testcase {
         $_POST['group'] = 0;
         $this->assertEquals(0, groups_get_activity_group($cm2, true));
 
-        $neighbours = forum_get_discussion_neighbours($cm2, $disc23);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc23, $forum2);
         $this->assertEmpty($neighbours['prev']);
         $this->assertEmpty($neighbours['next']);
 
-        $neighbours = forum_get_discussion_neighbours($cm2, $disc22);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc22, $forum2);
         $this->assertEmpty($neighbours['prev']);
         $this->assertEquals($disc23->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm2, $disc24);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc24, $forum2);
         $this->assertEquals($disc23->id, $neighbours['prev']->id);
         $this->assertEmpty($neighbours['next']);
 
@@ -1149,30 +1335,224 @@ class mod_forum_lib_testcase extends advanced_testcase {
         $this->assertEquals($group1->id, groups_get_activity_group($cm2, true));
 
         // They can see non-grouped or same group.
-        $neighbours = forum_get_discussion_neighbours($cm1, $disc11);
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc11, $forum1);
         $this->assertEmpty($neighbours['prev']);
         $this->assertEquals($disc13->id, $neighbours['next']->id);
-        $neighbours = forum_get_discussion_neighbours($cm2, $disc21);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc21, $forum2);
         $this->assertEmpty($neighbours['prev']);
         $this->assertEquals($disc23->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm1, $disc13);
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc13, $forum1);
         $this->assertEquals($disc11->id, $neighbours['prev']->id);
         $this->assertEquals($disc15->id, $neighbours['next']->id);
-        $neighbours = forum_get_discussion_neighbours($cm2, $disc23);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc23, $forum2);
         $this->assertEquals($disc21->id, $neighbours['prev']->id);
         $this->assertEquals($disc25->id, $neighbours['next']->id);
 
-        $neighbours = forum_get_discussion_neighbours($cm1, $disc15);
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc15, $forum1);
         $this->assertEquals($disc13->id, $neighbours['prev']->id);
         $this->assertEmpty($neighbours['next']);
-        $neighbours = forum_get_discussion_neighbours($cm2, $disc25);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc25, $forum2);
         $this->assertEquals($disc23->id, $neighbours['prev']->id);
         $this->assertEmpty($neighbours['next']);
 
         // Querying the neighbours of a discussion passing the wrong CM.
         $this->setExpectedException('coding_exception');
-        forum_get_discussion_neighbours($cm2, $disc11);
+        forum_get_discussion_neighbours($cm2, $disc11, $forum2);
+    }
+
+    /**
+     * Test getting the neighbour threads of a blog-like forum with groups involved.
+     */
+    public function test_forum_get_neighbours_with_groups_blog() {
+        $this->resetAfterTest();
+
+        // Setup test data.
+        $forumgen = $this->getDataGenerator()->get_plugin_generator('mod_forum');
+        $course = $this->getDataGenerator()->create_course();
+        $group1 = $this->getDataGenerator()->create_group(array('courseid' => $course->id));
+        $group2 = $this->getDataGenerator()->create_group(array('courseid' => $course->id));
+        $user1 = $this->getDataGenerator()->create_user();
+        $user2 = $this->getDataGenerator()->create_user();
+        $this->getDataGenerator()->enrol_user($user1->id, $course->id);
+        $this->getDataGenerator()->enrol_user($user2->id, $course->id);
+        $this->getDataGenerator()->create_group_member(array('userid' => $user1->id, 'groupid' => $group1->id));
+
+        $forum1 = $this->getDataGenerator()->create_module('forum', array('course' => $course->id, 'type' => 'blog',
+                'groupmode' => VISIBLEGROUPS));
+        $forum2 = $this->getDataGenerator()->create_module('forum', array('course' => $course->id, 'type' => 'blog',
+                'groupmode' => SEPARATEGROUPS));
+        $cm1 = get_coursemodule_from_instance('forum', $forum1->id);
+        $cm2 = get_coursemodule_from_instance('forum', $forum2->id);
+        $context1 = context_module::instance($cm1->id);
+        $context2 = context_module::instance($cm2->id);
+
+        // Creating blog posts in both forums.
+        $record = new stdClass();
+        $record->course = $course->id;
+        $record->userid = $user1->id;
+        $record->forum = $forum1->id;
+        $record->groupid = $group1->id;
+        $disc11 = $forumgen->create_discussion($record);
+        $record->forum = $forum2->id;
+        $disc21 = $forumgen->create_discussion($record);
+
+        sleep(1);
+        $record->userid = $user2->id;
+        $record->forum = $forum1->id;
+        $record->groupid = $group2->id;
+        $disc12 = $forumgen->create_discussion($record);
+        $record->forum = $forum2->id;
+        $disc22 = $forumgen->create_discussion($record);
+
+        sleep(1);
+        $record->userid = $user1->id;
+        $record->forum = $forum1->id;
+        $record->groupid = null;
+        $disc13 = $forumgen->create_discussion($record);
+        $record->forum = $forum2->id;
+        $disc23 = $forumgen->create_discussion($record);
+
+        sleep(1);
+        $record->userid = $user2->id;
+        $record->forum = $forum1->id;
+        $record->groupid = $group2->id;
+        $disc14 = $forumgen->create_discussion($record);
+        $record->forum = $forum2->id;
+        $disc24 = $forumgen->create_discussion($record);
+
+        sleep(1);
+        $record->userid = $user1->id;
+        $record->forum = $forum1->id;
+        $record->groupid = $group1->id;
+        $disc15 = $forumgen->create_discussion($record);
+        $record->forum = $forum2->id;
+        $disc25 = $forumgen->create_discussion($record);
+
+        // Admin user can see all groups.
+        $this->setAdminUser();
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc11, $forum1);
+        $this->assertEmpty($neighbours['prev']);
+        $this->assertEquals($disc12->id, $neighbours['next']->id);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc21, $forum2);
+        $this->assertEmpty($neighbours['prev']);
+        $this->assertEquals($disc22->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc12, $forum1);
+        $this->assertEquals($disc11->id, $neighbours['prev']->id);
+        $this->assertEquals($disc13->id, $neighbours['next']->id);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc22, $forum2);
+        $this->assertEquals($disc21->id, $neighbours['prev']->id);
+        $this->assertEquals($disc23->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc13, $forum1);
+        $this->assertEquals($disc12->id, $neighbours['prev']->id);
+        $this->assertEquals($disc14->id, $neighbours['next']->id);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc23, $forum2);
+        $this->assertEquals($disc22->id, $neighbours['prev']->id);
+        $this->assertEquals($disc24->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc14, $forum1);
+        $this->assertEquals($disc13->id, $neighbours['prev']->id);
+        $this->assertEquals($disc15->id, $neighbours['next']->id);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc24, $forum2);
+        $this->assertEquals($disc23->id, $neighbours['prev']->id);
+        $this->assertEquals($disc25->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc15, $forum1);
+        $this->assertEquals($disc14->id, $neighbours['prev']->id);
+        $this->assertEmpty($neighbours['next']);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc25, $forum2);
+        $this->assertEquals($disc24->id, $neighbours['prev']->id);
+        $this->assertEmpty($neighbours['next']);
+
+        // Admin user is only viewing group 1.
+        $_POST['group'] = $group1->id;
+        $this->assertEquals($group1->id, groups_get_activity_group($cm1, true));
+        $this->assertEquals($group1->id, groups_get_activity_group($cm2, true));
+
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc11, $forum1);
+        $this->assertEmpty($neighbours['prev']);
+        $this->assertEquals($disc13->id, $neighbours['next']->id);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc21, $forum2);
+        $this->assertEmpty($neighbours['prev']);
+        $this->assertEquals($disc23->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc13, $forum1);
+        $this->assertEquals($disc11->id, $neighbours['prev']->id);
+        $this->assertEquals($disc15->id, $neighbours['next']->id);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc23, $forum2);
+        $this->assertEquals($disc21->id, $neighbours['prev']->id);
+        $this->assertEquals($disc25->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc15, $forum1);
+        $this->assertEquals($disc13->id, $neighbours['prev']->id);
+        $this->assertEmpty($neighbours['next']);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc25, $forum2);
+        $this->assertEquals($disc23->id, $neighbours['prev']->id);
+        $this->assertEmpty($neighbours['next']);
+
+        // Normal user viewing non-grouped posts (this is only possible in visible groups).
+        $this->setUser($user1);
+        $_POST['group'] = 0;
+        $this->assertEquals(0, groups_get_activity_group($cm1, true));
+
+        // They can see anything in visible groups.
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc12, $forum1);
+        $this->assertEquals($disc11->id, $neighbours['prev']->id);
+        $this->assertEquals($disc13->id, $neighbours['next']->id);
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc13, $forum1);
+        $this->assertEquals($disc12->id, $neighbours['prev']->id);
+        $this->assertEquals($disc14->id, $neighbours['next']->id);
+
+        // Normal user, orphan of groups, can only see non-grouped posts in separate groups.
+        $this->setUser($user2);
+        $_POST['group'] = 0;
+        $this->assertEquals(0, groups_get_activity_group($cm2, true));
+
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc23, $forum2);
+        $this->assertEmpty($neighbours['prev']);
+        $this->assertEmpty($neighbours['next']);
+
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc22, $forum2);
+        $this->assertEmpty($neighbours['prev']);
+        $this->assertEquals($disc23->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc24, $forum2);
+        $this->assertEquals($disc23->id, $neighbours['prev']->id);
+        $this->assertEmpty($neighbours['next']);
+
+        // Switching to viewing group 1.
+        $this->setUser($user1);
+        $_POST['group'] = $group1->id;
+        $this->assertEquals($group1->id, groups_get_activity_group($cm1, true));
+        $this->assertEquals($group1->id, groups_get_activity_group($cm2, true));
+
+        // They can see non-grouped or same group.
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc11, $forum1);
+        $this->assertEmpty($neighbours['prev']);
+        $this->assertEquals($disc13->id, $neighbours['next']->id);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc21, $forum2);
+        $this->assertEmpty($neighbours['prev']);
+        $this->assertEquals($disc23->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc13, $forum1);
+        $this->assertEquals($disc11->id, $neighbours['prev']->id);
+        $this->assertEquals($disc15->id, $neighbours['next']->id);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc23, $forum2);
+        $this->assertEquals($disc21->id, $neighbours['prev']->id);
+        $this->assertEquals($disc25->id, $neighbours['next']->id);
+
+        $neighbours = forum_get_discussion_neighbours($cm1, $disc15, $forum1);
+        $this->assertEquals($disc13->id, $neighbours['prev']->id);
+        $this->assertEmpty($neighbours['next']);
+        $neighbours = forum_get_discussion_neighbours($cm2, $disc25, $forum2);
+        $this->assertEquals($disc23->id, $neighbours['prev']->id);
+        $this->assertEmpty($neighbours['next']);
+
+        // Querying the neighbours of a discussion passing the wrong CM.
+        $this->setExpectedException('coding_exception');
+        forum_get_discussion_neighbours($cm2, $disc11, $forum2);
     }
 
     public function test_count_discussion_replies_basic() {
diff --git a/mod/forum/view.php b/mod/forum/view.php
index af2c8d7ffb0..483fed79ce9 100644
--- a/mod/forum/view.php
+++ b/mod/forum/view.php
@@ -207,9 +207,10 @@
         case 'blog':
             echo '<br />';
             if (!empty($showall)) {
-                forum_print_latest_discussions($course, $forum, 0, 'plain', '', -1, -1, -1, 0, $cm);
+                forum_print_latest_discussions($course, $forum, 0, 'plain', 'p.created DESC', -1, -1, -1, 0, $cm);
             } else {
-                forum_print_latest_discussions($course, $forum, -1, 'plain', '', -1, -1, $page, $CFG->forum_manydiscussions, $cm);
+                forum_print_latest_discussions($course, $forum, -1, 'plain', 'p.created DESC', -1, -1, $page,
+                    $CFG->forum_manydiscussions, $cm);
             }
             break;