StackOverflowException when obfuscating pattern matching switch

[boq]

Replicated in Proguard 7.6.0 and JDK 21.0.2.

Reproduction case:

public class SwitchTest {
    public interface Type {
    }

    public enum Types implements Type {A}

    public static String test(final Type type) {
        return switch (type) {
            case Types.A -> "a";
            default -> "?";
        };
    }
}

Repeated stacktrace section looks like this:

	at proguard.classfile.ProgramClass.attributesAccept(ProgramClass.java:613)
	at proguard.classfile.editor.ConstantPoolShrinker.visitDynamicConstant(ConstantPoolShrinker.java:142)
	at proguard.classfile.constant.DynamicConstant.accept(DynamicConstant.java:109)
	at proguard.classfile.ProgramClass.constantPoolEntryAccept(ProgramClass.java:555)
	at proguard.classfile.attribute.BootstrapMethodInfo.methodArgumentsAccept(BootstrapMethodInfo.java:57)
	at proguard.classfile.editor.ConstantPoolShrinker.visitBootstrapMethodInfo(ConstantPoolShrinker.java:403)
	at proguard.classfile.attribute.BootstrapMethodsAttribute.bootstrapMethodEntriesAccept(BootstrapMethodsAttribute.java:58)
	at proguard.classfile.editor.ConstantPoolShrinker.visitBootstrapMethodsAttribute(ConstantPoolShrinker.java:209)
	at proguard.classfile.attribute.BootstrapMethodsAttribute.accept(BootstrapMethodsAttribute.java:49)
	at proguard.classfile.ProgramClass.attributesAccept(ProgramClass.java:613)

It seems to be triggered by Dynamic entry (and probably InvokeDynamic) in any of the arguments in BootstrapMethods attribute. Code in visitDynamicConstant seems to pass visitor back to class, which visits all attributes, eventually running back into BootstrapMethods and repeating whole process.

[rgaschy]

I've encountered the exact same issue.
It can still be reproduced on proguard 7.6.1 and JDK 21.0.2.
Here attached is a simple project that allows to reproduce the issue:

• unzip it
• run gradlew obfuscate --stacktrace
  (Basically, it wraps the class above in a gradle project)

proguard.zip

Would you please have a look at this issue?