RFR: 8347291: Exhaustive switch over a generic sealed abstract class

[Jan Lahoda]

On Fri, 24 Jan 2025 01:08:56 GMT, Liam Miller-Cushon <cushon at openjdk.org> wrote:

> This change avoids javac incorrectly reporting switches like the example in [JDK-8347291](https://bugs.openjdk.org/browse/JDK-8347291) as exhaustive.
> 
> As Jan noted in the bug it seems like the inference behaviour here may not be correct. If it was able to infer a type without crashing that would also avoid the bug.
> 
> However with the current inference behaviour, it's safer to assume that if inference crashes the subtype may need to be handled by the switch, instead of assuming that it doesn't.

FWIW: there was this attempt:
https://github.com/lahodaj/jdk/commit/108e5afa2bca60c5ae9b1270c23865aa615bfe52
but it requires more discussion on what exactly should the inference do.

-------------

PR Comment: https://git.openjdk.org/jdk/pull/23286#issuecomment-2613083536