Because the call to the constructor of HiveClientImpl crosses class loader
boundaries, different versions of the same class (Configuration in this
case) were loaded, and that caused a runtime error when instantiating the
client. By using a safer type in the signature of the constructor, it's
possible to avoid the problem.
I considered removing 'sharesHadoopClasses', but it may still be desired
(even though there are 0 users of it since it was not working). When Spark
starts to support Hadoop 3, it may be necessary to use that option to
load clients for older Hive metastore versions that don't know about
Hadoop 3.
Tested with added unit test.
Author: Marcelo Vanzin <vanzin@cloudera.com>
Closes#20169 from vanzin/SPARK-17088.
dc4761fd8f