Program: 63983
Project: 63983
Buggy source:
@Override public void accept(Event<StackDeleteRequest> stackDeleteRequest){
  final StackDeleteRequest data=stackDeleteRequest.getData();
  retryingStackUpdater.updateStackStatus(data.getStackId(),Status.DELETE_IN_PROGRESS,"String_Node_Str");
  final Stack stack=stackRepository.findOneWithLists(data.getStackId());
  MDCBuilder.buildMdcContext(stack);
  LOGGER.info("String_Node_Str",ReactorConfig.DELETE_REQUEST_EVENT);
  try {
    if (!data.getCloudPlatform().isWithTemplate()) {
      ResourceBuilderInit resourceBuilderInit=resourceBuilderInits.get(data.getCloudPlatform());
      final DeleteContextObject dCO=resourceBuilderInit.deleteInit(stack);
      List<Future<ResourceRequestResult>> futures=new ArrayList<>();
      for (int i=instanceResourceBuilders.get(data.getCloudPlatform()).size() - 1; i >= 0; i--) {
        final int index=i;
        List<Resource> resourceByType=stack.getResourcesByType(instanceResourceBuilders.get(data.getCloudPlatform()).get(i).resourceType());
        for (        final Resource resource : resourceByType) {
          Future<ResourceRequestResult> submit=resourceBuilderExecutor.submit(new Callable<ResourceRequestResult>(){
            @Override public ResourceRequestResult call() throws Exception {
              try {
                instanceResourceBuilders.get(data.getCloudPlatform()).get(index).delete(resource,dCO,stack.getRegion());
                retryingStackUpdater.removeStackResources(stack.getId(),Arrays.asList(resource));
                return ResourceRequestResult.ResourceRequestResultBuilder.builder().withFutureResult(FutureResult.SUCCESS).withInstanceGroup(stack.getInstanceGroupByInstanceGroupName(resource.getInstanceGroup())).build();
              }
 catch (              Exception ex) {
                return ResourceRequestResult.ResourceRequestResultBuilder.builder().withException(ex).withFutureResult(FutureResult.FAILED).withInstanceGroup(stack.getInstanceGroupByInstanceGroupName(resource.getInstanceGroup())).build();
              }
            }
          }
);
          futures.add(submit);
          if (provisionUtil.isRequestFull(stack,futures.size() + 1)) {
            Map<FutureResult,List<ResourceRequestResult>> result=provisionUtil.waitForRequestToFinish(stack.getId(),futures);
            provisionUtil.checkErrorOccurred(result);
            futures=new ArrayList<>();
          }
        }
      }
      Map<FutureResult,List<ResourceRequestResult>> result=provisionUtil.waitForRequestToFinish(stack.getId(),futures);
      provisionUtil.checkErrorOccurred(result);
      for (int i=networkResourceBuilders.get(data.getCloudPlatform()).size() - 1; i >= 0; i--) {
        for (        Resource resource : stack.getResourcesByType(networkResourceBuilders.get(data.getCloudPlatform()).get(i).resourceType())) {
          networkResourceBuilders.get(data.getCloudPlatform()).get(i).delete(resource,dCO,stack.getRegion());
        }
      }
      reactor.notify(ReactorConfig.DELETE_COMPLETE_EVENT,Event.wrap(new StackDeleteComplete(dCO.getStackId())));
    }
 else {
      cloudPlatformConnectors.get(data.getCloudPlatform()).deleteStack(stack,stack.getCredential());
    }
  }
 catch (  Exception ex) {
    LOGGER.error(String.format("String_Node_Str",stack.getId()),ex);
    retryingStackUpdater.updateStackStatus(data.getStackId(),Status.DELETE_FAILED,"String_Node_Str" + ex.getMessage());
  }
}

Fixed version (ground truth):
@Override public void accept(Event<StackDeleteRequest> stackDeleteRequest){
  final StackDeleteRequest data=stackDeleteRequest.getData();
  retryingStackUpdater.updateStackStatus(data.getStackId(),Status.DELETE_IN_PROGRESS,"String_Node_Str");
  final Stack stack=stackRepository.findOneWithLists(data.getStackId());
  MDCBuilder.buildMdcContext(stack);
  LOGGER.info("String_Node_Str",ReactorConfig.DELETE_REQUEST_EVENT);
  try {
    if (!data.getCloudPlatform().isWithTemplate()) {
      ResourceBuilderInit resourceBuilderInit=resourceBuilderInits.get(data.getCloudPlatform());
      final DeleteContextObject dCO=resourceBuilderInit.deleteInit(stack);
      List<Future<ResourceRequestResult>> futures=new ArrayList<>();
      for (int i=instanceResourceBuilders.get(data.getCloudPlatform()).size() - 1; i >= 0; i--) {
        final int index=i;
        List<Resource> resourceByType=stack.getResourcesByType(instanceResourceBuilders.get(data.getCloudPlatform()).get(i).resourceType());
        for (        final Resource resource : resourceByType) {
          Future<ResourceRequestResult> submit=resourceBuilderExecutor.submit(new Callable<ResourceRequestResult>(){
            @Override public ResourceRequestResult call() throws Exception {
              try {
                instanceResourceBuilders.get(data.getCloudPlatform()).get(index).delete(resource,dCO,stack.getRegion());
                retryingStackUpdater.removeStackResources(stack.getId(),Arrays.asList(resource));
                return ResourceRequestResult.ResourceRequestResultBuilder.builder().withFutureResult(FutureResult.SUCCESS).withInstanceGroup(stack.getInstanceGroupByInstanceGroupName(resource.getInstanceGroup())).build();
              }
 catch (              Exception ex) {
                return ResourceRequestResult.ResourceRequestResultBuilder.builder().withException(ex).withFutureResult(FutureResult.FAILED).withInstanceGroup(stack.getInstanceGroupByInstanceGroupName(resource.getInstanceGroup())).build();
              }
            }
          }
);
          futures.add(submit);
          if (provisionUtil.isRequestFull(stack,futures.size() + 1)) {
            Map<FutureResult,List<ResourceRequestResult>> result=provisionUtil.waitForRequestToFinish(stack.getId(),futures);
            checkErrorOccurred(result);
            futures=new ArrayList<>();
          }
        }
      }
      Map<FutureResult,List<ResourceRequestResult>> result=provisionUtil.waitForRequestToFinish(stack.getId(),futures);
      checkErrorOccurred(result);
      for (int i=networkResourceBuilders.get(data.getCloudPlatform()).size() - 1; i >= 0; i--) {
        for (        Resource resource : stack.getResourcesByType(networkResourceBuilders.get(data.getCloudPlatform()).get(i).resourceType())) {
          networkResourceBuilders.get(data.getCloudPlatform()).get(i).delete(resource,dCO,stack.getRegion());
        }
      }
      reactor.notify(ReactorConfig.DELETE_COMPLETE_EVENT,Event.wrap(new StackDeleteComplete(dCO.getStackId())));
    }
 else {
      cloudPlatformConnectors.get(data.getCloudPlatform()).deleteStack(stack,stack.getCredential());
    }
  }
 catch (  Exception ex) {
    LOGGER.error(String.format("String_Node_Str",stack.getId()),ex);
    retryingStackUpdater.updateStackStatus(data.getStackId(),Status.DELETE_FAILED,"String_Node_Str" + ex.getMessage());
  }
}