HADOOP-11618 fixed a bug with DelegateToFileSystem using the wrong default port. As a side effect of this patch, file path URLs that previously had no port now insert :0 for the port, as per the default implementation of FileSystem#getDefaultPort. At runtime, this can cause an application to erroneously try contacting port 0 for a remote blob store service. The connection fails. Ultimately, this renders wasb, s3, and probably custom file system implementations outside the Hadoop source tree completely unusable as the default file system.