Merge branch 'MDL-63892-36-rework' of git://github.com/mickhawkins/mo…

…odle into MOODLE_36_STABLE

mod/forum/lib.php

@@ -4029,7 +4029,7 @@ function forum_print_discussion_header(&$post, $forum, $group = -1, $datestring
     }
 
     echo '<td class="lastpost">';
-    $usedate = (empty($post->created)) ? $post->timemodified : $post->created;
+    $usedate = (empty($post->timemodified)) ? $post->created : $post->timemodified;
     $parenturl = '';
     $usermodified = new stdClass();
     $usermodified->id = $post->usermodified;
@@ -4662,10 +4662,6 @@ function forum_update_post($newpost, $mform, $unused = null) {
     }
     $post->modified = time();
 
-    // Last post modified tracking.
-    $discussion->timemodified = $post->modified;
-    $discussion->usermodified = $post->userid;
-
     if (!$post->parent) {   // Post is a discussion starter - update discussion title and times too
         $discussion->name      = $post->subject;
         $discussion->timestart = $post->timestart;
@@ -4678,6 +4674,7 @@ function forum_update_post($newpost, $mform, $unused = null) {
     $post->message = file_save_draft_area_files($newpost->itemid, $context->id, 'mod_forum', 'post', $post->id,
             mod_forum_post_form::editor_options($context, $post->id), $post->message);
     $DB->update_record('forum_posts', $post);
+    // Note: Discussion modified time/user are intentionally not updated, to enable them to track the latest new post.
     $DB->update_record('forum_discussions', $discussion);
 
     forum_add_attachment($post, $forum, $cm, $mform);

mod/forum/post.php

@@ -593,7 +593,7 @@
 
 if ($USER->id != $post->userid) {   // Not the original author, so add a message to the end.
     $data = new stdClass();
-    $data->date = userdate($post->modified);
+    $data->date = userdate($post->created);
     if ($post->messageformat == FORMAT_HTML) {
         $data->name = '<a href="'.$CFG->wwwroot.'/user/view.php?id='.$USER->id.'&course='.$post->course.'">'.
             fullname($USER).'</a>';

mod/forum/tests/lib_test.php

@@ -3298,6 +3298,17 @@ public function test_forum_update_post_keeps_discussions_usermodified() {
         // On this freshly created discussion, the teacher is the author of the last post.
         $this->assertEquals($teacher->id, $DB->get_field('forum_discussions', 'usermodified', ['id' => $discussion->id]));
 
+        // Fetch modified timestamp of the discussion.
+        $discussionmodified = $DB->get_field('forum_discussions', 'timemodified', ['id' => $discussion->id]);
+        $pasttime = $discussionmodified - 3600;
+
+        // Adjust the discussion modified timestamp back an hour, so it's in the past.
+        $adjustment = (object)[
+            'id' => $discussion->id,
+            'timemodified' => $pasttime,
+        ];
+        $DB->update_record('forum_discussions', $adjustment);
+
         // Let the student reply to the teacher's post.
         $reply = $generator->create_post((object)[
             'course' => $course->id,
@@ -3310,6 +3321,30 @@ public function test_forum_update_post_keeps_discussions_usermodified() {
         // The student should now be the last post's author.
         $this->assertEquals($student->id, $DB->get_field('forum_discussions', 'usermodified', ['id' => $discussion->id]));
 
+        // Fetch modified timestamp of the discussion and student's post.
+        $discussionmodified = $DB->get_field('forum_discussions', 'timemodified', ['id' => $discussion->id]);
+        $postmodified = $DB->get_field('forum_posts', 'modified', ['id' => $reply->id]);
+
+        // Discussion modified time should be updated to be equal to the newly created post's time.
+        $this->assertEquals($discussionmodified, $postmodified);
+
+        // Adjust the discussion and post timestamps, so they are in the past.
+        $adjustment = (object)[
+            'id' => $discussion->id,
+            'timemodified' => $pasttime,
+        ];
+        $DB->update_record('forum_discussions', $adjustment);
+
+        $adjustment = (object)[
+            'id' => $reply->id,
+            'modified' => $pasttime,
+        ];
+        $DB->update_record('forum_posts', $adjustment);
+
+        // The discussion and student's post time should now be an hour in the past.
+        $this->assertEquals($pasttime, $DB->get_field('forum_discussions', 'timemodified', ['id' => $discussion->id]));
+        $this->assertEquals($pasttime, $DB->get_field('forum_posts', 'modified', ['id' => $reply->id]));
+
         // Let the teacher edit the student's reply.
         $this->setUser($teacher->id);
         $newpost = (object)[
@@ -3319,8 +3354,14 @@ public function test_forum_update_post_keeps_discussions_usermodified() {
         ];
         forum_update_post($newpost, null);
 
-        // The student should be still the last post's author.
+        // The student should still be the last post's author.
         $this->assertEquals($student->id, $DB->get_field('forum_discussions', 'usermodified', ['id' => $discussion->id]));
+
+        // The discussion modified time should not have changed.
+        $this->assertEquals($pasttime, $DB->get_field('forum_discussions', 'timemodified', ['id' => $discussion->id]));
+
+        // The post time should be updated.
+        $this->assertGreaterThan($pasttime, $DB->get_field('forum_posts', 'modified', ['id' => $reply->id]));
     }
 
     public function test_forum_core_calendar_provide_event_action() {