Map reduce fails when providing an S3N folder as input

Bug is on cdh version 0.20.2+737.

Steps to reproduce:
1. Create an S3 bucket and folder.
2. Upload 1 file to the folder.
3. Run the identity map reduce job on that folder.
4. It will incorrectly say that the number of inputs to process is 2, erroneously counting the folder as an input.
5. In the middle of the map-reduce job, it will fail with a null pointer exception and the job wont complete.

The same map reduce job works perfectly fine on apache hadoop 0.21 (latest release from apache).

java.lang.NullPointerException
at org.apache.hadoop.fs.s3native.NativeS3FileSystem$NativeS3FsInputStream.close(NativeS3FileSystem.java:129)
at java.io.BufferedInputStream.close(BufferedInputStream.java:451)
at java.io.FilterInputStream.close(FilterInputStream.java:155)
at org.apache.hadoop.util.LineReader.close(LineReader.java:83)
at org.apache.hadoop.mapred.LineRecordReader.close(LineRecordReader.java:171)
at org.apache.hadoop.mapred.MapTask$TrackedRecordReader.close(MapTask.java:208)
at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:387)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:317)
at org.apache.hadoop.mapred.Child$4.run(Child.java:217)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:396)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1063)
at org.apache.hadoop.mapred.Child.main(Child.java:211)