Remove public + static from class definitions in interfaces (#491)

* Remove public + static from class definitions in interfaces

* Fix tests

Author: Owen1212055

src/org/jetbrains/java/decompiler/main/ClassWriter.java

@@ -641,6 +641,15 @@ private void writeClassDefinition(ClassNode node, TextBuffer buffer, int indent)
       }
     }
 
+    // Classes defined inside of interfaces are implicitly public/static (JLS 9.5 Member Type Declarations)
+    if (
+      node.type == ClassNode.Type.MEMBER &&
+      (node.parent.getWrapper().getClassStruct().getAccessFlags() & CodeConstants.ACC_INTERFACE) != 0
+    ) {
+      flags &= ~CodeConstants.ACC_PUBLIC;
+      flags &= ~CodeConstants.ACC_STATIC;
+    }
+
     if (interceptor != null) {
       String oldName = interceptor.getOldName(cl.qualifiedName);
       appendRenameComment(buffer, oldName, MType.CLASS, indent);

testData/results/pkg/MoreAnnotations.dec

@@ -95,11 +95,11 @@ public @interface MoreAnnotations {
 
    Class<? extends CharSequence>[] classArray() default {CharSequence.class, String.class, StringBuilder.class};
 
-   public @interface NestedAnnotation {
+   @interface NestedAnnotation {
       String value() default "MyString";
    }
 
-   public static enum TestEnum {
+   enum TestEnum {
       FirstValue,
       SecondValue;
    }

testData/results/pkg/TestGenericSubclassTypes.dec

@@ -15,14 +15,14 @@ public interface TestGenericSubclassTypes<T> {
       return i -> i;// 27
    }
 
-   public static class Constant<T> implements TestGenericSubclassTypes.Numerical<T> {
+   class Constant<T> implements TestGenericSubclassTypes.Numerical<T> {
       @Override
       public int get(T in) {
          return 1;// 16
       }
    }
 
-   public interface Numerical<T> {
+   interface Numerical<T> {
       int get(T var1);
    }
 }

testData/results/pkg/TestInterfaceSubclass.dec

@@ -5,11 +5,11 @@ public interface TestInterfaceSubclass {
 
    int doOtherThing();
 
-   public abstract static class AbstractClass implements TestInterfaceSubclass {
+   abstract class AbstractClass implements TestInterfaceSubclass {
       public abstract double doDoubleThing();
    }
 
-   public static class Multiple extends TestInterfaceSubclass.AbstractClass implements TestInterfaceSubclass {
+   class Multiple extends TestInterfaceSubclass.AbstractClass implements TestInterfaceSubclass {
       @Override
       public void doThing() {
          System.out.println("Hello");// 29
@@ -26,7 +26,7 @@ public interface TestInterfaceSubclass {
       }
    }
 
-   public static class Subclass implements TestInterfaceSubclass {
+   class Subclass implements TestInterfaceSubclass {
       @Override
       public void doThing() {
          System.out.println("Hi");// 12

testData/results/pkg/TestInterfaceSuper.dec

@@ -4,7 +4,7 @@ public interface TestInterfaceSuper {
    default void defaultMethod() {
    }// 4
 
-   public static class Impl implements TestInterfaceSuper {
+   class Impl implements TestInterfaceSuper {
       @Override
       public void defaultMethod() {
          TestInterfaceSuper.super.defaultMethod();// 8

testData/results/pkg/TestRecordPatterns6.dec

@@ -25,13 +25,13 @@ public class TestRecordPatterns6 {
    }
 
    sealed interface I permits TestRecordPatterns6.I.R1, TestRecordPatterns6.I.R2, TestRecordPatterns6.I.R3 {
-      public record R1(Object o) implements TestRecordPatterns6.I {
+      record R1(Object o) implements TestRecordPatterns6.I {
       }
 
-      public record R2(int i) implements TestRecordPatterns6.I {
+      record R2(int i) implements TestRecordPatterns6.I {
       }
 
-      public record R3(String s) implements TestRecordPatterns6.I {
+      record R3(String s) implements TestRecordPatterns6.I {
       }
    }
 }