HADOOP-14630 adds some contract tests trying to create files or rename files under other files.
On a rename under an existing file (or dir under an existing file), HDFS fails throwing org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.fs.ParentNotDirectoryException).
- is throwing an exception here what people agree is the correct behaviour? If so, it can go into the filesystem spec, tests set up to expect it. object stores tweaked for consistency. If not, HDFS needs a change.
- At the very least, HDFS should be unwrapping the exception.