[SPARK-9130][SQL] throw exception when check equality between external and internal row

[cloud-fan]

instead of return false, throw exception when check equality between external and internal row is better.

[cloud-fan]

cc @rxin

[rxin]

LGTM

[rxin]

technically you want .eq instead of == i think, because == actually triggers the equality of the other function

[cloud-fan]

I tried, but eq accepts AnyRef, here o is Any. I googled it, looks like x == null is OK for null check in scala.

[rxin]

alright then lgtm

[rxin]

let's see if we have any places that we mistakenly compare

[SparkQA]

Test build #37599 timed out for PR 7460 at commit 402daa8 after a configured wait of 175m.

[cloud-fan]

finally figure out how to use eq to do null check here...

[SparkQA]

Test build #37632 has finished for PR 7460 at commit 8a20911.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[rxin]

Thanks - merging this in.