[jdk19] RFR: JDK-8289894: A NullPointerException thrown from guard expression
Vicente Romero
vromero at openjdk.org
Fri Jul 8 16:27:27 UTC 2022
On Thu, 7 Jul 2022 14:48:09 GMT, Jan Lahoda <jlahoda at openjdk.org> wrote:
> Consider the following code:
>
> public class SwitchGuard {
> public static void main(String... args) {
> test(null);
> }
> private static void test(Object o) {
> switch (o) {
> case null, String s when s.isEmpty() -> System.err.println("OK.");
> default -> {}
> }
> }
> }
>
>
> In the current specification, the guard should not be invoked when `o` is `null`, but javac will invoke it, for historical reasons.
>
> Also, as opposed to JDK 18/JEP 420, `case null, <pattern>` is allowed for parenthesized pattern when the parenthesized pattern encloses (directly or via other parenthesized patterns) a type pattern.
>
> The patch proposed here strives to fix both of these problems.
looks sensible
-------------
Marked as reviewed by vromero (Reviewer).
PR: https://git.openjdk.org/jdk19/pull/120
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