s3a doesn't consider blobs with trailing / and content-length >0 as directories

When creating a directory using the AWS Management Console, the content-length is set to 0 and s3a works fine.

When creating a directory using other tools, like S3Browse, the content-length is set to 1 and s3a doesn't work:
S3AFileSystem: Found file (with /): real file? should not happen: dir1