Program: 71280
Project: 71280
Buggy source:
protected boolean performInsert(Object model,PropertyHandle propertyHandle,String type,String position,Map extendData) throws Exception {
  if (type == null) {
    if (propertyHandle == null) {
      DesignElementHandle handle=((CrosstabCellHandle)((ExtendedItemHandle)model).getReportItem()).getModelHandle();
      propertyHandle=((ExtendedItemHandle)model).getPropertyHandle(DEUtil.getDefaultContentName(handle));
    }
    List supportList=UIUtil.getUIElementSupportList(propertyHandle);
    if (supportList.size() == 0) {
      ExceptionHandler.openMessageBox(WARNING_DIALOG_TITLE,WARNING_DIALOG_MESSAGE_EMPTY_LIST,SWT.ICON_WARNING);
      return false;
    }
 else     if (supportList.size() == 1) {
      type=((IElementDefn)supportList.get(0)).getName();
    }
 else {
      NewSectionDialog dialog=new NewSectionDialog(PlatformUI.getWorkbench().getDisplay().getActiveShell(),supportList);
      if (dialog.open() == Dialog.CANCEL) {
        return false;
      }
      type=(String)dialog.getResult()[0];
    }
  }
  PaletteEntryExtension[] entries=EditpartExtensionManager.getPaletteEntries();
  for (int i=0; i < entries.length; i++) {
    if (entries[i].getItemName().equals(type)) {
      extendData.put(IRequestConstants.REQUEST_KEY_RESULT,entries[i].executeCreate());
      return true;
    }
  }
  DesignElementHandle elementHandle=createElement(type);
  if (extendData != null) {
    extendData.put(IRequestConstants.REQUEST_KEY_RESULT,elementHandle);
  }
  if (elementHandle == null) {
    return false;
  }
 else {
    int pos=DNDUtil.calculateNextPosition(model,DNDUtil.handleValidateTargetCanContain(model,elementHandle,true));
    if (pos > 0 && position == InsertAction.ABOVE) {
      pos--;
    }
    if (pos == -1) {
      propertyHandle.add(elementHandle);
    }
 else {
      propertyHandle.add(elementHandle,pos);
    }
  }
  if (elementHandle instanceof ExtendedItemHandle) {
    if (ElementProcessorFactory.createProcessor(elementHandle) != null && !ElementProcessorFactory.createProcessor(elementHandle).editElement(elementHandle)) {
      return false;
    }
  }
  return true;
}

Fixed version (ground truth):
protected boolean performInsert(Object model,PropertyHandle propertyHandle,String type,String position,Map extendData) throws Exception {
  if (type == null) {
    if (propertyHandle == null) {
      DesignElementHandle handle=((CrosstabCellHandle)((ExtendedItemHandle)model).getReportItem()).getModelHandle();
      propertyHandle=((ExtendedItemHandle)model).getPropertyHandle(DEUtil.getDefaultContentName(handle));
    }
    List supportList=UIUtil.getUIElementSupportList(propertyHandle);
    if (supportList.size() == 0) {
      ExceptionUtil.openMessage(WARNING_DIALOG_TITLE,WARNING_DIALOG_MESSAGE_EMPTY_LIST,SWT.ICON_WARNING);
      return false;
    }
 else     if (supportList.size() == 1) {
      type=((IElementDefn)supportList.get(0)).getName();
    }
 else {
      NewSectionDialog dialog=new NewSectionDialog(PlatformUI.getWorkbench().getDisplay().getActiveShell(),supportList);
      if (dialog.open() == Dialog.CANCEL) {
        return false;
      }
      type=(String)dialog.getResult()[0];
    }
  }
  PaletteEntryExtension[] entries=EditpartExtensionManager.getPaletteEntries();
  for (int i=0; i < entries.length; i++) {
    if (entries[i].getItemName().equals(type)) {
      extendData.put(IRequestConstants.REQUEST_KEY_RESULT,entries[i].executeCreate());
      return true;
    }
  }
  DesignElementHandle elementHandle=createElement(type);
  if (extendData != null) {
    extendData.put(IRequestConstants.REQUEST_KEY_RESULT,elementHandle);
  }
  if (elementHandle == null) {
    return false;
  }
 else {
    int pos=DNDUtil.calculateNextPosition(model,DNDUtil.handleValidateTargetCanContain(model,elementHandle,true));
    if (pos > 0 && position == InsertAction.ABOVE) {
      pos--;
    }
    if (pos == -1) {
      propertyHandle.add(elementHandle);
    }
 else {
      propertyHandle.add(elementHandle,pos);
    }
  }
  if (elementHandle instanceof ExtendedItemHandle) {
    if (ElementProcessorFactory.createProcessor(elementHandle) != null && !ElementProcessorFactory.createProcessor(elementHandle).editElement(elementHandle)) {
      return false;
    }
  }
  return true;
}