[SPARK-11594][SQL][REPL] Cannot create UDAF in REPL

[hvanhovell]

This PR enables users to create a UDAF in the REPL without getting a java.lang.InternalError.

[hvanhovell]

I am not catching a java.lang.InternalError here, because I think these shouldn't be caught at all (the error could have different cause). We enable the use to redefine the name to work arround this problem.

[yhuai]

I am wondering if we can catch the error and re-throw it with a more informative error message (we put InternalError as the cause of our new error)? In our error message, we can let the user know he/she potentially hit that Scala issue and the workaround is to override def name.

[SparkQA]

Test build #45364 has finished for PR 9568 at commit 401230c.

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

[yhuai]

So, this is the cause of that InternalError?

[hvanhovell]

The getSimpleName call on the defined class causes the internal error.

[hvanhovell]

This is actually a scala problem:
https://issues.scala-lang.org/browse/SI-9051
https://issues.scala-lang.org/browse/SI-2034

[yhuai]

How about we add the link to the scala issue in our description and in our code comment?

[hvanhovell]

Sounds like a good idea. I'll add this in the morning.

[hvanhovell]

Move to scala 2.10.5 fixed this. Closing PR.