src/share/classes/javax/swing/plaf/basic/BasicScrollBarUI.java

*** 1263,1273 ****
              if (scrollbar.getParent() instanceof JScrollPane) {
                  JScrollPane scrollpane = (JScrollPane)scrollbar.getParent();
                  JViewport viewport = scrollpane.getViewport();
                  Component view = viewport.getView();
                  if (view instanceof JList) {
!                     JList list = (JList)view;
                      if (DefaultLookup.getBoolean(list, list.getUI(),
                                                   "List.lockToPositionOnScroll", false)) {
                          int adjustedValue = value;
                          int mode = list.getLayoutOrientation();
                          int orientation = scrollbar.getOrientation();
--- 1263,1274 ----
              if (scrollbar.getParent() instanceof JScrollPane) {
                  JScrollPane scrollpane = (JScrollPane)scrollbar.getParent();
                  JViewport viewport = scrollpane.getViewport();
                  Component view = viewport.getView();
                  if (view instanceof JList) {
!                     @SuppressWarnings("unchecked")
!                     JList<Object> list = (JList)view;
                      if (DefaultLookup.getBoolean(list, list.getUI(),
                                                   "List.lockToPositionOnScroll", false)) {
                          int adjustedValue = value;
                          int mode = list.getLayoutOrientation();
                          int orientation = scrollbar.getOrientation();