Update upstream#120

Merged

GulajavaMinistudio merged 3 commits into

GulajavaMinistudio:masterfrom

Aug 1, 2017

Commits on Jul 31, 2017

[MINOR] Minor comment fixes in merge_spark_pr.py script
HyukjinKwon
committed
[SPARK-19839][CORE] release longArray in BytesToBytesMap

Zhan Zhang
authored and
gatorsmile
committed
[SPARK-21575][SPARKR] Eliminate needless synchronization in java-R serialization

SereneAnt
authored and
yanboliang
committed