Attached is a couple extra tests which run filecmp on two files with different content but the same length and relevant stat() info. This appears to successfully check if the shallow options works correctly. 

It uses time.sleep(1) to ensure the files start out with different creation times, checks that filecmp returns false, then sets the creation time with os.utime to ensure filecmp is true.

These tests currently run successfully on 3.5, so if there was an issue, it has been resolved.