Fix AsyncRequestBody.fromByteBuffers() never completes when no buffers are given

[Fred1155]

Motivation and Context

AsyncRequestBody.fromByteBuffers() takes a varargs of ByteBuffer:

static AsyncRequestBody fromByteBuffers(ByteBuffer... byteBuffers) {
    ...
}

if byteBuffers is empty, the Subscriber's onComplete() is never called. In this example, the future never completes:

public class FromByteBuffers {
    public static void main(String[] args) {
        S3AsyncClient s3 = S3AsyncClient.builder()
                .region(Region.US_WEST_2)
                .build();

        AsyncRequestBody noBuffers = AsyncRequestBody.fromByteBuffers();

        s3.putObject(r -> r.bucket("test").key("empty"), noBuffers).join();
    }
}

This issue exists for all the variants that takes varargs of ByteBuffer:

fromByteBuffers
fromByteBuffersUnsafe
fromRemainingByteBuffers
fromRemainingByteBuffersUnsafe

Modifications

Added code in ByteBuffersAsyncRequestBody to handle the case when i >= buffers.length. In this case, we need to consider the subscription completed.

Testing

Added unit test for no ByteBuffersAsyncRequestBody when no buffer is given

Screenshots (if appropriate)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Checklist

• I have read the CONTRIBUTING document
• Local run of mvn install succeeds
• My code follows the code style of this project
• My change requires a change to the Javadoc documentation
• I have updated the Javadoc documentation accordingly
• I have added tests to cover my changes
• All new and existing tests passed
• I have added a changelog entry. Adding a new entry must be accomplished by running the scripts/new-change script and following the instructions. Commit the new file created by the script in .changes/next-release with your changes.
• My change is to implement 1.11 parity feature and I have updated LaunchChangelog

License

• I confirm that this pull request can be released under the Apache 2 license

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

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