Effective visibility: fix for internal & protected vs protected comparison #KT-9582 Fixed

compiler/testData/diagnostics/tests/exposed/internalAndProtected.kt

@@ -0,0 +1,10 @@
+public open class A {
+    protected open class B
+}
+
+public open class C : A() {
+    protected open class D {
+        // internal & protected(in C) <= protected(in A): Ok
+        internal open class E : A.B() 
+    }
+}

compiler/testData/diagnostics/tests/exposed/internalAndProtected.txt

@@ -0,0 +1,36 @@
+package
+
+public open class A {
+    public constructor A()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+    protected open class B {
+        public constructor B()
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+}
+
+public open class C : A {
+    public constructor C()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+    protected open class D {
+        public constructor D()
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+        internal open class E : A.B {
+            public constructor E()
+            public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+            public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+            public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+        }
+    }
+}

compiler/tests/org/jetbrains/kotlin/checkers/JetDiagnosticsTestGenerated.java

@@ -5802,6 +5802,12 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("internalAndProtected.kt")
+            public void testInternalAndProtected() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/exposed/internalAndProtected.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("local.kt")
             public void testLocal() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/exposed/local.kt");

core/descriptors/src/org/jetbrains/kotlin/descriptors/EffectiveVisibility.kt

@@ -75,8 +75,9 @@ sealed class EffectiveVisibility(val name: String) {
             Private, ProtectedBound, InternalProtectedBound -> Permissiveness.MORE
             is Protected -> containerRelation(container, other.container)
             is InternalProtected -> when (containerRelation(container, other.container)) {
-                    Permissiveness.SAME, Permissiveness.LESS -> Permissiveness.LESS
+                // Protected never can be less permissive than internal & protected
-                    Permissiveness.UNKNOWN, Permissiveness.MORE -> Permissiveness.UNKNOWN
+                Permissiveness.SAME, Permissiveness.MORE -> Permissiveness.MORE
+                Permissiveness.UNKNOWN, Permissiveness.LESS -> Permissiveness.UNKNOWN
             }
             Internal -> Permissiveness.UNKNOWN
         }
@@ -127,8 +128,9 @@ sealed class EffectiveVisibility(val name: String) {
             Private, InternalProtectedBound -> Permissiveness.MORE
             is InternalProtected -> containerRelation(container, other.container)
             is Protected -> when (containerRelation(container, other.container)) {
-                Permissiveness.SAME, Permissiveness.MORE -> Permissiveness.MORE
+                // Internal & protected never can be more permissive than just protected
-                Permissiveness.UNKNOWN, Permissiveness.LESS -> Permissiveness.UNKNOWN
+                Permissiveness.SAME, Permissiveness.LESS -> Permissiveness.LESS
+                Permissiveness.UNKNOWN, Permissiveness.MORE -> Permissiveness.UNKNOWN
             }
             ProtectedBound -> Permissiveness.UNKNOWN
         }