Program: 51901
Project: 51901
Buggy source:
/** 
 * Process a node in the metadata registry XML file. The node must be a "dc-type" node.  If the type already exists, then it will not be reimported
 * @param context DSpace context object
 * @param node the node in the DOM tree
 * @throws NonUniqueMetadataException
 */
private static void loadType(Context context,Node node) throws SQLException, IOException, TransformerException, AuthorizeException, NonUniqueMetadataException, RegistryImportException {
  String schema=RegistryImporter.getElementData(node,"String_Node_Str");
  String element=RegistryImporter.getElementData(node,"String_Node_Str");
  String qualifier=RegistryImporter.getElementData(node,"String_Node_Str");
  String scopeNote=RegistryImporter.getElementData(node,"String_Node_Str");
  if (schema == null) {
    schema=MetadataSchema.DC_SCHEMA;
  }
  MetadataSchema schemaObj=metadataSchemaService.find(context,schema);
  if (schemaObj == null) {
    throw new RegistryImportException("String_Node_Str" + schema + "String_Node_Str");
  }
  MetadataField mf=metadataFieldService.findByElement(context,schemaObj,element,qualifier);
  if (mf != null) {
    return;
  }
  String fieldName=schema + "String_Node_Str" + element+ "String_Node_Str"+ qualifier;
  if (qualifier == null)   fieldName=schema + "String_Node_Str" + element;
  log.info("String_Node_Str" + fieldName);
  MetadataField field=metadataFieldService.create(context,schemaObj,element,qualifier,scopeNote);
  metadataFieldService.update(context,field);
}

Fixed version (ground truth):
/** 
 * Process a node in the metadata registry XML file. The node must be a "dc-type" node.  If the type already exists, then it will not be reimported
 * @param context DSpace context object
 * @param node the node in the DOM tree
 * @throws SQLException if database error
 * @throws IOException if IO error
 * @throws TransformerException if transformer error
 * @throws AuthorizeException if authorization error
 * @throws NonUniqueMetadataException if duplicate metadata
 * @throws RegistryImportException if import fails
 */
private static void loadType(Context context,Node node) throws SQLException, IOException, TransformerException, AuthorizeException, NonUniqueMetadataException, RegistryImportException {
  String schema=RegistryImporter.getElementData(node,"String_Node_Str");
  String element=RegistryImporter.getElementData(node,"String_Node_Str");
  String qualifier=RegistryImporter.getElementData(node,"String_Node_Str");
  String scopeNote=RegistryImporter.getElementData(node,"String_Node_Str");
  if (schema == null) {
    schema=MetadataSchema.DC_SCHEMA;
  }
  MetadataSchema schemaObj=metadataSchemaService.find(context,schema);
  if (schemaObj == null) {
    throw new RegistryImportException("String_Node_Str" + schema + "String_Node_Str");
  }
  MetadataField mf=metadataFieldService.findByElement(context,schemaObj,element,qualifier);
  if (mf != null) {
    return;
  }
  String fieldName=schema + "String_Node_Str" + element+ "String_Node_Str"+ qualifier;
  if (qualifier == null)   fieldName=schema + "String_Node_Str" + element;
  log.info("String_Node_Str" + fieldName);
  MetadataField field=metadataFieldService.create(context,schemaObj,element,qualifier,scopeNote);
  metadataFieldService.update(context,field);
}