svn merge -c 1463221 FIXES: MAPREDUCE-4974. Optimising the LineRecordReader initialize() method (Gelesh via bobby)


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1463224 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/branch-0.23' into branch-0.23-gd
Merge remote branch 'origin/branch-0.23-gd' into fb-HADOOP-9291-branch-0.23-gd