BucketExistsAsync throwing NullReferenceException when Bucket doesn't exist

[renatokenji]

Hi,

I'm having the exact same issue described in #714 but my client is instantiated correctly calling the .Build() at the end. I've already tested other operations and everything is running fine, I can upload/download and list objects but I decided to implement the bucket verification just in case and i'm getting this error.

Code for the client

private const string Bucket = "BucketTestName";
private const string ContentType = "application/pdf";
private readonly MinioClient _client = new MinioClient().WithEndpoint(Url)
            .WithCredentials(AccessKey, SecretKey)
            .WithSSL().Build();

Code for putting an object in the bucket

        public async Task Add(ArquivoMinio arquivo)
        {
            try
            {
                var argss = new BucketExistsArgs().WithBucket(Bucket);
                var bucketExists = await _client.BucketExistsAsync(argss); //this line throws the exception
                if (!bucketExists)
                {
                    await CreateBucket();
                }

                using var dados = new MemoryStream(arquivo.Base64);
                var args = new PutObjectArgs().WithBucket(Bucket).WithObject($"{arquivo.Caminho}")
                    .WithStreamData(dados).WithObjectSize(arquivo.Base64.Length)
                    .WithContentType(ContentType);
                await _client.PutObjectAsync(args);
            }
            catch (MinioException e)
            {
                //ommited for brevity
            }
        }

Everything is running and working. Its just that BucketExistsAsync verification that throws the same error from the issue mentioned

System.NullReferenceException: Object reference not set to an instance of an object.
   at Minio.MinioClient.ParseErrorFromContent(ResponseResult response) in /_/Minio/MinioClient.cs:line 608
   at Minio.MinioClient.ParseError(ResponseResult response) in /_/Minio/MinioClient.cs:line 477
   at Minio.MinioClient.<>c.<.ctor>b__94_0(ResponseResult response) in /_/Minio/MinioClient.cs:line 47
   at Minio.MinioClient.HandleIfErrorResponse(ResponseResult response, IEnumerable`1 handlers, DateTime startTime) in /_/Minio/MinioClient.cs:line 670
   at Minio.MinioClient.ExecuteTaskCoreAsync(IEnumerable`1 errorHandlers, HttpRequestMessageBuilder requestMessageBuilder, Boolean isSts, CancellationToken cancellationToken) in /_/Minio/MinioClient.cs:line 451
   at Minio.BucketRegionCache.Update(MinioClient client, String bucketName) in /_/Minio/BucketRegionCache.cs:line 99
   at Minio.MinioClient.GetRegion(String bucketName) in /_/Minio/MinioClient.cs:line 202
   at Minio.MinioClient.CreateRequest(HttpMethod method, String bucketName, String objectName, IDictionary`2 headerMap, String contentType, ReadOnlyMemory`1 body, String resourcePath, Boolean isBucketCreationRequest) in /_/Minio/MinioClient.cs:line 291
   at Minio.MinioClient.CreateRequest[T](BucketArgs`1 args) in /_/Minio/MinioClient.cs:line 232
   at Minio.MinioClient.BucketExistsAsync(BucketExistsArgs args, CancellationToken cancellationToken) in /_/Minio/ApiEndpoints/BucketOperations.cs:line 67

This happens only when the Bucket doesn't exist. I tried running the code with the name of a existing bucket and it also runs fine and proceeds to put the object successfully.

I'm using MinIO version 5.0.0 and the server version is 2023-06-29T05:12:28Z

[criedsky]

I have the same issue when trying to create a new bucket.
Working fine for put/get file from an exist bucket.

[xiangxiren]

Minio server version is low.

[ebozduman]

@renatokenji , @criedsky

I believe this issue is fixed in PR #844

Could you please test it and close this issue if it passes your test?

[renatokenji]

@ebozduman fixed. Updated to 6.0.0 with same server version. Thank you, closing this issue.