Program: 53618
Project: 53618
Buggy source:
/** 
 * Preview the   {@link NativePreviewEvent}.
 * @param event the {@link NativePreviewEvent}
 */
private void previewNativeEvent(NativePreviewEvent event){
  if (event.isCanceled() || (!previewAllNativeEvents && event.isConsumed())) {
    if (modal) {
      event.cancel();
    }
    return;
  }
  onPreviewNativeEvent(event);
  if (event.isCanceled()) {
    return;
  }
  Event nativeEvent=Event.as(event.getNativeEvent());
  boolean eventTargetsPopupOrPartner=eventTargetsPopup(nativeEvent) || eventTargetsPartner(nativeEvent);
  if (eventTargetsPopupOrPartner) {
    event.consume();
  }
  if (modal) {
    event.cancel();
  }
  int type=nativeEvent.getTypeInt();
switch (type) {
case Event.ONKEYDOWN:
{
      if (!onKeyDownPreview((char)nativeEvent.getKeyCode(),KeyboardListenerCollection.getKeyboardModifiers(nativeEvent))) {
        event.cancel();
      }
      return;
    }
case Event.ONKEYUP:
{
    if (!onKeyUpPreview((char)nativeEvent.getKeyCode(),KeyboardListenerCollection.getKeyboardModifiers(nativeEvent))) {
      event.cancel();
    }
    return;
  }
case Event.ONKEYPRESS:
{
  if (!onKeyPressPreview((char)nativeEvent.getKeyCode(),KeyboardListenerCollection.getKeyboardModifiers(nativeEvent))) {
    event.cancel();
  }
  return;
}
case Event.ONMOUSEDOWN:
if (DOM.getCaptureElement() != null) {
event.consume();
return;
}
if (!eventTargetsPopupOrPartner && autoHide) {
hide(true);
return;
}
break;
case Event.ONMOUSEUP:
case Event.ONMOUSEMOVE:
case Event.ONCLICK:
case Event.ONDBLCLICK:
{
if (DOM.getCaptureElement() != null) {
event.consume();
return;
}
break;
}
case Event.ONFOCUS:
{
Element target=nativeEvent.getTarget();
if (modal && !eventTargetsPopupOrPartner && (target != null)) {
blur(target);
event.cancel();
return;
}
break;
}
}
}

Fixed version (ground truth):
/** 
 * Preview the   {@link NativePreviewEvent}.
 * @param event the {@link NativePreviewEvent}
 */
private void previewNativeEvent(NativePreviewEvent event){
  if (event.isCanceled() || (!previewAllNativeEvents && event.isConsumed())) {
    if (modal) {
      event.cancel();
    }
    return;
  }
  onPreviewNativeEvent(event);
  if (event.isCanceled()) {
    return;
  }
  Event nativeEvent=Event.as(event.getNativeEvent());
  boolean eventTargetsPopupOrPartner=eventTargetsPopup(nativeEvent) || eventTargetsPartner(nativeEvent);
  if (eventTargetsPopupOrPartner) {
    event.consume();
  }
  if (modal) {
    event.cancel();
  }
  int type=nativeEvent.getTypeInt();
switch (type) {
case Event.ONKEYDOWN:
{
      if (!onKeyDownPreview((char)nativeEvent.getKeyCode(),KeyboardListenerCollection.getKeyboardModifiers(nativeEvent))) {
        event.cancel();
      }
      return;
    }
case Event.ONKEYUP:
{
    if (!onKeyUpPreview((char)nativeEvent.getKeyCode(),KeyboardListenerCollection.getKeyboardModifiers(nativeEvent))) {
      event.cancel();
    }
    return;
  }
case Event.ONKEYPRESS:
{
  if (!onKeyPressPreview((char)nativeEvent.getKeyCode(),KeyboardListenerCollection.getKeyboardModifiers(nativeEvent))) {
    event.cancel();
  }
  return;
}
case Event.ONMOUSEDOWN:
case Event.ONTOUCHSTART:
if (DOM.getCaptureElement() != null) {
event.consume();
return;
}
if (!eventTargetsPopupOrPartner && autoHide) {
hide(true);
return;
}
break;
case Event.ONMOUSEUP:
case Event.ONMOUSEMOVE:
case Event.ONCLICK:
case Event.ONDBLCLICK:
case Event.ONTOUCHEND:
{
if (DOM.getCaptureElement() != null) {
event.consume();
return;
}
break;
}
case Event.ONFOCUS:
{
Element target=nativeEvent.getTarget();
if (modal && !eventTargetsPopupOrPartner && (target != null)) {
blur(target);
event.cancel();
return;
}
break;
}
}
}