Ticket #3083: 3083.patch

src/includes/topics/functions.php

@@ -2982 +2982 @@
         delete_post_meta( $topic_id, '_bbp_engagement' );
 
         // Query the DB to get voices in this topic
+        // See: https://bbpress.trac.wordpress.org/ticket/3083
         $bbp_db  = bbp_db();
-        $sql     = "SELECT DISTINCT post_author FROM {$bbp_db->posts} WHERE ( post_parent = %d AND post_status = %s AND post_type = %s ) OR ( ID = %d AND post_type = %s )";
-        $query   = $bbp_db->prepare( $sql, $topic_id, bbp_get_public_status_id(), bbp_get_reply_post_type(), $topic_id, bbp_get_topic_post_type() );
+        $sql     = "SELECT DISTINCT( post_author ) FROM ( 
+                                        SELECT post_author FROM {$bbp_db->posts} 
+                                                WHERE ( ID = %d AND post_type = %s ) 
+                                        UNION 
+                                        SELECT post_author FROM {$bbp_db->posts}  
+                                                WHERE ( post_parent = %d AND post_status = %s AND post_type = %s )
+                                ) as u1";
+        $query   = $bbp_db->prepare( $sql, $topic_id, bbp_get_topic_post_type(), $topic_id, bbp_get_public_status_id(), bbp_get_reply_post_type() );
         $results = $bbp_db->get_col( $query );
 
         // Parse results into voices