https://spark-project.atlassian.net/browse/SPARK-1240
It seems that the current implementation does not handle the empty RDD case when run takeSample
In this patch, before calling sample() inside takeSample API, I add a checker for this case and returns an empty Array when it's a empty RDD; also in sample(), I add a checker for the invalid fraction value
In the test case, I also add several lines for this case
Author: CodingCat <zhunansjtu@gmail.com>
Closes#135 from CodingCat/SPARK-1240 and squashes the following commits:
fef57d4 [CodingCat] fix the same problem in PySpark
36db06b [CodingCat] create new test cases for takeSample from an empty red
810948d [CodingCat] further fix
a40e8fb [CodingCat] replace if with require
ad483fd [CodingCat] handle the case with empty RDD when take sample
dc9654638f