table from directory subtree having no descendent files fails with index error

Trying to use as a table a directory subtree that has no descendent files (but zero or more descendent directories) yields what seems to be a partially handled index out-of-bounds condition.

For example, with /tmp/empty_directory being an empty directory:

0: jdbc:drill:zk=local> SELECT * FROM `dfs`.`tmp`.`empty_directory`;
Error: VALIDATION ERROR: Index: 0, Size: 0


[Error Id: 747425c9-5350-4813-9f0d-ecf580e15101 on dev-linux2:31010] (state=,code=0)
0: jdbc:drill:zk=local> 

Also, with /tmp/no_child_files_subtree having two child directories and a grandchild directory, but not descendent files:

0: jdbc:drill:zk=local> SELECT * FROM `dfs`.`tmp`.`no_child_files_subtree`;
Error: VALIDATION ERROR: Index: 0, Size: 0


[Error Id: abc90424-8434-4403-b44b-0ba69ef43151 on dev-linux2:31010] (state=,code=0)
0: jdbc:drill:zk=local> 

A directory subtree having no files was expected to be taken as a table with no rows (and a null schema).