Fix inner classes

accesstransformers/src/main/java/net/neoforged/jst/accesstransformers/ApplyATsVisitor.java

@@ -254,7 +254,7 @@ private void checkImplicitConstructor(PsiClass psiClass, String className, @Null
         } else if (psiClass.getClassKind() == JvmClassKind.CLASS) {
             // When widening the access of a class, we must take into consideration the fact that implicit constructors follow the access level of their owner
             if (psiClass.getConstructors().length == 0) {
-                var constructorTarget = new Target.MethodTarget(className, "<init>", "()V");
+                var constructorTarget = new Target.MethodTarget(className, "<init>", PsiHelper.getImplicitConstructorSignature(psiClass));
                 var constructorAt = pendingATs.remove(constructorTarget);
 
                 if (classAt != null && detectModifier(psiClass.getModifierList(), null).ordinal() > classAt.modifier().ordinal()) {

api/src/main/java/net/neoforged/jst/api/PsiHelper.java

@@ -80,6 +80,20 @@ public String next() {
         };
     }
 
+    public static String getImplicitConstructorSignature(PsiClass psiClass) {
+        StringBuilder signature = new StringBuilder();
+        signature.append("(");
+        // Non-Static inner class constructors have the enclosing class as their first argument
+        if (isNonStaticInnerClass(psiClass)) {
+            var parent = Objects.requireNonNull(Objects.requireNonNull(psiClass.getContainingClass()));
+            signature.append("L");
+            getBinaryClassName(parent, signature);
+            signature.append(";");
+        }
+        signature.append(")V");
+        return signature.toString();
+    }
+
     public static String getBinaryMethodSignature(PsiMethod method) {
         StringBuilder signature = new StringBuilder();
         signature.append("(");
@@ -165,13 +179,15 @@ private static boolean isEnumConstructor(PsiMethod method) {
     private static boolean isNonStaticInnerClassConstructor(PsiMethod method) {
         if (method.isConstructor()) {
             var containingClass = method.getContainingClass();
-            return containingClass != null
-                    && containingClass.getContainingClass() != null
-                    && !containingClass.hasModifierProperty(PsiModifier.STATIC);
+            return containingClass != null && isNonStaticInnerClass(containingClass);
         }
         return false;
     }
 
+    private static boolean isNonStaticInnerClass(PsiClass psiClass) {
+        return psiClass.getContainingClass() != null && !psiClass.hasModifierProperty(PsiModifier.STATIC);
+    }
+
     /**
      * Gets the local variable table indices of the parameters for the given method
      * or lambda expression

tests/data/accesstransformer/implicit_constructors/accesstransformer.cfg

@@ -10,3 +10,6 @@ public PrivateRecord # Error because the ctor needs to be AT'd too
 
 public PrivateRecord$Nested
 public PrivateRecord$Nested <init>(I)V
+
+protected PrivateClass$Inner # Make the class itself protected
+public PrivateClass$Inner <init>(LPrivateClass;)V # and the constructor public

tests/data/accesstransformer/implicit_constructors/expected/PrivateClass.java

@@ -8,4 +8,9 @@ protected static class NestedProtected {
     public static class Both {
 
     }
+
+    protected class Inner {
+        public Inner() {}
+
+    }
 }

tests/data/accesstransformer/implicit_constructors/source/PrivateClass.java

@@ -7,4 +7,8 @@ protected static class NestedProtected {
     protected static class Both {
 
     }
+
+    private class Inner {
+
+    }
 }