Merge -r 1640170:1640171 from trunk to branch. Fixes: AVRO-1596. Java: Cannot read past corrupted block in Avro data file.

git-svn-id: https://svn.apache.org/repos/asf/avro/branches/branch-1.7@1640173 13f79535-47bb-0310-9956-ffa450edef68