apache/spark — pull request #1357 by ueshin (2014-07-10 16:26:33+00:00)
Title: [SPARK-2431][SQL] Refine StringComparison and related codes.

Refine `StringComparison` and related codes as follows:
- `StringComparison` could be similar to `StringRegexExpression` or `CaseConversionExpression`.
- Nullability of `StringRegexExpression` could depend on children's nullabilities.
- Add a case that the like condition includes no wildcard to `LikeSimplification`.