SwitchDefault crash in 2.10.0 when handling new-style switch with a default case

[dododge]

Given a switchstatement that uses the newer -> notation but does not yield a value, the presence of a default case seems to trigger an exception in the SwitchDefault rule.

Using error-prone 2.10.0 (and Java 16 since that's what I already had installed).

Sample code:

public class Example
{
    public static void nothing1() { }
    public static void nothing2() { }
    public static void nothing3() { }

    public static void switchDefaultCrash(int i)
    {
        switch(i) {
            case 0 -> nothing1();
            case 1 -> nothing2();
            default -> nothing3();
        }
    }
}

Stack trace from maven:

[ERROR]      error-prone version: 2.10.0
[ERROR]      BugPattern: SwitchDefault
[ERROR]      Stack Trace:
[ERROR]      java.lang.NullPointerException: Cannot invoke "java.util.List.isEmpty()" because the return value of "com.sun.source.tree.CaseTree.getStatements()" is null
[ERROR]   	at com.google.errorprone.bugpatterns.SwitchDefault.matchSwitch(SwitchDefault.java:65)
[ERROR]   	at com.google.errorprone.scanner.ErrorProneScanner.processMatchers(ErrorProneScanner.java:449)
[ERROR]   	at com.google.errorprone.scanner.ErrorProneScanner.visitSwitch(ErrorProneScanner.java:823)
[ERROR]   	at com.google.errorprone.scanner.ErrorProneScanner.visitSwitch(ErrorProneScanner.java:150)
[ERROR]   	at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCSwitch.accept(JCTree.java:1256)
[ERROR]   	at jdk.compiler/com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:86)
[ERROR]   	at com.google.errorprone.scanner.Scanner.scan(Scanner.java:74)
[ERROR]   	at com.google.errorprone.scanner.Scanner.scan(Scanner.java:48)
[ERROR]   	at jdk.compiler/com.sun.source.util.TreeScanner.scan(TreeScanner.java:109)
[ERROR]   	at jdk.compiler/com.sun.source.util.TreeScanner.visitBlock(TreeScanner.java:254)
[ERROR]   	at com.google.errorprone.scanner.ErrorProneScanner.visitBlock(ErrorProneScanner.java:520)
[ERROR]   	at com.google.errorprone.scanner.ErrorProneScanner.visitBlock(ErrorProneScanner.java:150)
[ERROR]   	at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:1059)
[ERROR]   	at jdk.compiler/com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:86)
[ERROR]   	at com.google.errorprone.scanner.Scanner.scan(Scanner.java:74)
[ERROR]   	at com.google.errorprone.scanner.Scanner.scan(Scanner.java:48)
[ERROR]   	at jdk.compiler/com.sun.source.util.TreeScanner.scanAndReduce(TreeScanner.java:94)
[ERROR]   	at jdk.compiler/com.sun.source.util.TreeScanner.visitMethod(TreeScanner.java:212)
[ERROR]   	at com.google.errorprone.scanner.ErrorProneScanner.visitMethod(ErrorProneScanner.java:740)
[ERROR]   	at com.google.errorprone.scanner.ErrorProneScanner.visitMethod(ErrorProneScanner.java:150)
[ERROR]   	at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:925)
[ERROR]   	at jdk.compiler/com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:86)
[ERROR]   	at com.google.errorprone.scanner.Scanner.scan(Scanner.java:74)
[ERROR]   	at com.google.errorprone.scanner.Scanner.scan(Scanner.java:48)
[ERROR]   	at jdk.compiler/com.sun.source.util.TreeScanner.scanAndReduce(TreeScanner.java:94)
[ERROR]   	at jdk.compiler/com.sun.source.util.TreeScanner.scan(TreeScanner.java:109)
[ERROR]   	at jdk.compiler/com.sun.source.util.TreeScanner.scanAndReduce(TreeScanner.java:117)
[ERROR]   	at jdk.compiler/com.sun.source.util.TreeScanner.visitClass(TreeScanner.java:193)
[ERROR]   	at com.google.errorprone.scanner.ErrorProneScanner.visitClass(ErrorProneScanner.java:548)
[ERROR]   	at com.google.errorprone.scanner.ErrorProneScanner.visitClass(ErrorProneScanner.java:150)
[ERROR]   	at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCClassDecl.accept(JCTree.java:832)
[ERROR]   	at jdk.compiler/com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:86)
[ERROR]   	at com.google.errorprone.scanner.Scanner.scan(Scanner.java:74)
[ERROR]   	at com.google.errorprone.scanner.Scanner.scan(Scanner.java:48)
[ERROR]   	at jdk.compiler/com.sun.source.util.TreeScanner.scan(TreeScanner.java:109)
[ERROR]   	at jdk.compiler/com.sun.source.util.TreeScanner.scanAndReduce(TreeScanner.java:117)
[ERROR]   	at jdk.compiler/com.sun.source.util.TreeScanner.visitCompilationUnit(TreeScanner.java:148)
[ERROR]   	at com.google.errorprone.scanner.ErrorProneScanner.visitCompilationUnit(ErrorProneScanner.java:560)
[ERROR]   	at com.google.errorprone.scanner.ErrorProneScanner.visitCompilationUnit(ErrorProneScanner.java:150)
[ERROR]   	at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCCompilationUnit.accept(JCTree.java:603)
[ERROR]   	at jdk.compiler/com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:60)
[ERROR]   	at com.google.errorprone.scanner.Scanner.scan(Scanner.java:58)
[ERROR]   	at com.google.errorprone.scanner.ErrorProneScannerTransformer.apply(ErrorProneScannerTransformer.java:43)
[ERROR]   	at com.google.errorprone.ErrorProneAnalyzer.finished(ErrorProneAnalyzer.java:152)
[ERROR]   	at jdk.compiler/com.sun.tools.javac.api.MultiTaskListener.finished(MultiTaskListener.java:132)
[ERROR]   	at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.flow(JavaCompiler.java:1421)
[ERROR]   	at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.flow(JavaCompiler.java:1368)
[ERROR]   	at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:960)
[ERROR]   	at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:317)
[ERROR]   	at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:176)
[ERROR]   	at jdk.compiler/com.sun.tools.javac.Main.compile(Main.java:64)
[ERROR]   	at jdk.compiler/com.sun.tools.javac.Main.main(Main.java:50)