Program: 13556
Project: 13556
Buggy source:
@Override public void execute(OperationRequest operation,OperationContext context,ParticipantId participant) throws InvalidRequestException {
  String capabilitiesHash=OperationUtil.getRequiredParameter(operation,ParamsProperty.CAPABILITIES_HASH);
  RobotName robotName=RobotName.fromAddress(participant.getAddress());
  ParticipantId robotAccountId=ParticipantId.ofUnsafe(robotName.toEmailAddress());
  AccountData account;
  try {
    account=accountStore.getAccount(robotAccountId);
  }
 catch (  PersistenceException e) {
    LOG.severe("String_Node_Str" + robotAccountId,e);
    context.constructErrorResponse(operation,"String_Node_Str");
    return;
  }
  if (account == null || !account.isRobot()) {
    throw new InvalidRequestException("String_Node_Str" + robotAccountId);
  }
  RobotAccountData robotAccountData=account.asRobot();
  RobotCapabilities capabilities=robotAccountData.getCapabilities();
  if (capabilities != null && capabilitiesHash.equals(capabilities.getCapabilitiesHash())) {
    context.constructResponse(operation,Maps.<ParamsProperty,Object>newHashMap());
    return;
  }
  try {
    robotAccountData=connector.fetchCapabilities(robotAccountData,"String_Node_Str");
  }
 catch (  CapabilityFetchException e) {
    LOG.fine("String_Node_Str" + account.getId(),e);
    context.constructErrorResponse(operation,"String_Node_Str");
    return;
  }
  try {
    accountStore.putAccount(robotAccountData);
  }
 catch (  PersistenceException e) {
    LOG.severe("String_Node_Str" + robotAccountId,e);
    context.constructErrorResponse(operation,"String_Node_Str");
    return;
  }
  context.constructResponse(operation,Maps.<ParamsProperty,Object>newHashMap());
}

Fixed version (ground truth):
@Override public void execute(OperationRequest operation,OperationContext context,ParticipantId participant) throws InvalidRequestException {
  String capabilitiesHash=OperationUtil.getRequiredParameter(operation,ParamsProperty.CAPABILITIES_HASH);
  ParticipantId robotAccountId=participant;
  AccountData account;
  try {
    account=accountStore.getAccount(robotAccountId);
  }
 catch (  PersistenceException e) {
    LOG.severe("String_Node_Str" + robotAccountId,e);
    context.constructErrorResponse(operation,"String_Node_Str");
    return;
  }
  if (account == null || !account.isRobot()) {
    throw new InvalidRequestException("String_Node_Str" + robotAccountId);
  }
  RobotAccountData robotAccountData=account.asRobot();
  RobotCapabilities capabilities=robotAccountData.getCapabilities();
  if (capabilities != null && capabilitiesHash.equals(capabilities.getCapabilitiesHash())) {
    context.constructResponse(operation,Maps.<ParamsProperty,Object>newHashMap());
    return;
  }
  try {
    robotAccountData=connector.fetchCapabilities(robotAccountData,"String_Node_Str");
  }
 catch (  CapabilityFetchException e) {
    LOG.fine("String_Node_Str" + account.getId(),e);
    context.constructErrorResponse(operation,"String_Node_Str");
    return;
  }
  try {
    accountStore.putAccount(robotAccountData);
  }
 catch (  PersistenceException e) {
    LOG.severe("String_Node_Str" + robotAccountId,e);
    context.constructErrorResponse(operation,"String_Node_Str");
    return;
  }
  context.constructResponse(operation,Maps.<ParamsProperty,Object>newHashMap());
}