MDL-15390 improved subscribe me option when posting to forum - see tracker for more info; merged from MOODLE_19_STABLE

mod/forum/lib.php

@@ -4275,7 +4275,17 @@ function forum_discussions_user_has_posted_in($forumid, $userid) {
  */
 function forum_user_has_posted($forumid, $did, $userid) {
     global $DB;
-    return $DB->record_exists('forum_posts', array('discussion'=>$did,'userid'=>$userid));
+
+    if (empty($did)) {
+        // posted in any forum discussion?
+        $sql = "SELECT 'x'
+                  FROM {forum_posts} p
+                  JOIN {forum_discussions} d ON d.id = p.discussion
+                 WHERE p.userid = :userid AND d.forum = :forumid";
+        return $DB->record_exists_sql($sql, array('forumid'=>$forumid,'userid'=>$userid));
+    } else {
+        return $DB->record_exists('forum_posts', array('discussion'=>$did,'userid'=>$userid));
+    }
 }
 
 /**

mod/forum/post.php

@@ -729,9 +729,17 @@
     }
 
     //load data into form
-    $subscribe=(isset($post->forum)&&forum_is_subscribed($USER->id, $post->forum)) ||
-                    (!empty($USER->autosubscribe));
 
+    if (forum_is_subscribed($USER->id, $forum->id)) {
+        $subscribe = true;
+
+    } else if (forum_user_has_posted($forum->id, 0, $USER->id)) {
+        $subscribe = false;
+        
+    } else {
+        // user not posted yet - use subscription default specified in profile
+        $subscribe = !empty($USER->autosubscribe);
+    }
 
     // HACK ALERT: this is very wrong, the defaults should be always initialized before calling $mform->get_data() !!!
     $mform_post->set_data(array(    'general'=>$heading,