Program: 62420
Project: 62420
Buggy source:
/** 
 * Performs any validation on the user input.
 * @return  <code>true</code> if the input is valid, <code>false</code> otherwise
 */
private boolean validateUserInput(){
  boolean isValid=true;
  if (!operatorDescriptor.isHandlingOutputName()) {
    File productDir=null;
    Object value=form.getPropertyValue(ToolAdapterConstants.TOOL_TARGET_PRODUCT_FILE);
    if (value != null && value instanceof File) {
      productDir=((File)value).getParentFile();
      appContext.getPreferences().setPropertyString(SaveProductAsAction.PREFERENCES_KEY_LAST_PRODUCT_DIR,((File)value).getAbsolutePath());
    }
    isValid=(productDir != null) && productDir.exists();
    if (!isValid) {
      warnings.add("String_Node_Str");
    }
  }
  List<ToolParameterDescriptor> mandatoryParams=operatorDescriptor.getToolParameterDescriptors().stream().filter(d -> d.isNotEmpty() || d.isNotNull()).collect(Collectors.toList());
  Map<String,Object> parameterMap=parameterSupport.getParameterMap();
  for (  ToolParameterDescriptor mandatoryParam : mandatoryParams) {
    String name=mandatoryParam.getName();
    if (!parameterMap.containsKey(name) || parameterMap.get(name) == null || parameterMap.get(name).toString().isEmpty()) {
      isValid=false;
      warnings.add(String.format("String_Node_Str",name));
    }
  }
  if (operatorDescriptor.getSourceProductCount() > 0) {
    Product[] sourceProducts=form.getSourceProducts();
    isValid&=(sourceProducts != null) && sourceProducts.length > 0 && Arrays.stream(sourceProducts).filter(sp -> sp == null).count() == 0;
    if (!isValid) {
      warnings.add("String_Node_Str");
    }
  }
  return isValid;
}

Fixed version (ground truth):
/** 
 * Performs any validation on the user input.
 * @return  <code>true</code> if the input is valid, <code>false</code> otherwise
 */
private boolean validateUserInput(){
  boolean isValid=true;
  if (!operatorDescriptor.isHandlingOutputName()) {
    File productDir=null;
    Object value=form.getPropertyValue(ToolAdapterConstants.TOOL_TARGET_PRODUCT_FILE);
    if (value != null && value instanceof File) {
      productDir=((File)value).getParentFile();
      appContext.getPreferences().setPropertyString(SaveProductAsAction.PREFERENCES_KEY_LAST_PRODUCT_DIR,((File)value).getAbsolutePath());
    }
    isValid=(productDir != null) && productDir.exists();
    if (!isValid) {
      warnings.add("String_Node_Str");
    }
  }
  List<ToolParameterDescriptor> mandatoryParams=operatorDescriptor.getToolParameterDescriptors().stream().filter(d -> d.isNotEmpty() || d.isNotNull()).collect(Collectors.toList());
  Map<String,Object> parameterMap=parameterSupport.getParameterMap();
  for (  ToolParameterDescriptor mandatoryParam : mandatoryParams) {
    String name=mandatoryParam.getName();
    if (!parameterMap.containsKey(name) || parameterMap.get(name) == null || parameterMap.get(name).toString().isEmpty()) {
      isValid=false;
      warnings.add(String.format("String_Node_Str",name));
    }
  }
  if (operatorDescriptor.getSourceProductCount() > 0) {
    Product[] sourceProducts=form.getSourceProducts();
    boolean isProdValid=(sourceProducts != null) && sourceProducts.length > 0 && Arrays.stream(sourceProducts).filter(sp -> sp == null).count() == 0;
    if (!isProdValid) {
      warnings.add("String_Node_Str");
    }
    isValid&=isProdValid;
  }
  return isValid;
}