Running Stat on GetObject before reading discards range

[klauspost]

Running the code:

		gopts := minio.GetObjectOptions{}
		err = gopts.SetRange(100, 1000)
		if err != nil {
			panic(err)
		}
		fmt.Println("HDR:", gopts.Header())
		c.TraceOn(os.Stdout)
		r, err := c.GetObject(context.Background(), bucketName, objectName, gopts)
		if err != nil {
			panic(err)
		}
		
		if false { // enable to get correct size
			_, err := io.ReadAll(r)
			if err != nil {
				panic(err)
			}
		}
		
		st, err := r.Stat()
		if err != nil {
			panic(err)
		}
		fmt.Println("Size:", st.Size)

This discards the range and the reported size is the full object. Enabling the read gives the expected size (901 bytes).

Without reading:

HEAD /minio-go-test-viijedtgbwiqglb3/ugmagqw0xesk0cckvwprlghclgj4fp HTTP/1.1
Host: 127.0.0.1:9001
User-Agent: MinIO (windows; amd64) minio-go/v7.0.53 MinIO-go-FunctionalTest/0.1.0
Authorization: AWS4-HMAC-SHA256 Credential=minio/20230428/us-east-1/s3/aws4_request, SignedHeaders=host;x-amz-checksum-mode;x-amz-content-sha256;x-amz-date, Signature=**REDACTED**
X-Amz-Content-Sha256: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
X-Amz-Date: 20230428T082415Z

When reading:

GET /minio-go-test-6sekkdglutgfh2b3/406ojw4qjhtfhz04bzktyeof153e3b HTTP/1.1
Host: 127.0.0.1:9001
User-Agent: MinIO (windows; amd64) minio-go/v7.0.53 MinIO-go-FunctionalTest/0.1.0
Authorization: AWS4-HMAC-SHA256 Credential=minio/20230428/us-east-1/s3/aws4_request, SignedHeaders=host;range;x-amz-checksum-mode;x-amz-content-sha256;x-amz-date, Signature=**REDACTED**
Range: bytes=100-1000
X-Amz-Content-Sha256: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
X-Amz-Date: 20230428T082515Z

Doing the read after the Stat still discards the Range:

GET /minio-go-test-nku3o02lbjak9g00/pk0a9aomse5lwbm4oaxzsicki5pt1q HTTP/1.1
Host: 127.0.0.1:9001
User-Agent: MinIO (windows; amd64) minio-go/v7.0.53 MinIO-go-FunctionalTest/0.1.0
Authorization: AWS4-HMAC-SHA256 Credential=minio/20230428/us-east-1/s3/aws4_request, SignedHeaders=host;if-match;x-amz-checksum-mode;x-amz-content-sha256;x-amz-date, Signature=**REDACTED**
If-Match: "f7234306c5f424246875f826ceae3e19"
X-Amz-Content-Sha256: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
X-Amz-Date: 20230428T082858Z

... and the full object is returned.