Tyler Hobbs as a follow up cassandra_src all time

f1662b1479c64213c06ac921631f7e1186619698 | Author: Tyler Hobbs <tylerlhobbs@gmail.com>
 | 2015-05-28 10:37:58-05:00

    Fix check for non-empty slice start
    
    Patch by Dave Brosius; reviewed by Tyler Hobbs as a follow up for
    CASSANDRA-8502