Don't consider filtered out tasks siblings when sorting in new tasks

Summary: BUG:396792

Reviewers: davidedmundson, broulik

Reviewed By: broulik

Subscribers: broulik, plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D14392

libtaskmanager/tasksmodel.cpp

@@ -552,8 +552,15 @@ void TasksModel::Private::updateManualSortMap()
                      const QModelIndex &concatProxyIndex = concatProxyModel->index(sortedPreFilterRows.at(i), 0);
 
                      if (appsMatch(concatProxyIndex, idx)) {
-                         sortedPreFilterRows.move(row, i + 1);
-                         moved = true;
+                         // Our sort map contains row indices prior to any filtering, but we don't
+                         // want to sort new tasks in next to siblings we're filtering out higher up
+                         // in the proxy chain, so check in with the filter model.
+                         const QModelIndex &filterProxyIndex = filterProxyModel->mapFromSource(concatProxyIndex);
+
+                         if (filterProxyIndex.isValid()) {
+                            sortedPreFilterRows.move(row, i + 1);
+                            moved = true;
+                         }
 
                          break;
                      }