Major Description
distcp on mr1(branch-1) fails with NPE using a short relative source path.
The failure is at DistCp.java, makeRelative return null at the following code:
The parameters passed to makeRelative are not same format:
root is relative path and child.getPath() is a full path.
final String dst = makeRelative(root, child.getPath());
The solution is
change root to full path to match child.getPath().