apache/spark — pull request #2891 by sarutak (2014-10-22 08:13:40+00:00)
Title: [SPARK-4045][SQL] BinaryArithmetic cannot implicitly cast StringType to DoubleType

If we use StringType for a operand for BinaryArithmetic, the operand is coerced to be DoubleType.
I think, the operand should be coerced to be the type of another operand.