YARN-618. Modified RM_INVALID_IDENTIFIER to be -1 instead of zero. Contributed by Jian He.
svn merge --ignore-ancestry -c 1478230 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1478235 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5193. A few MR tests use block sizes which are smaller than the default minimum block size. Contributed by Andrew Wang.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1478251 13f79535-47bb-0310-9956-ffa450edef68