Protected in final inspection: protected modifier is effectively private in final classes #KT-6674 Fixed

idea/testData/inspections/protectedInFinal/inspectionData/expected.xml

@@ -0,0 +1,26 @@
+<problems>
+    <problem>
+        <file>protectedInFinal.kt</file>
+        <line>2</line>
+        <module>light_idea_test_case</module>
+        <entry_point TYPE="file" FQNAME="temp:///src/protectedInFinal.kt" />
+        <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">'protected' visibility is effectively 'private' in a final class</problem_class>
+        <description>'protected' visibility is effectively 'private' in a final class</description>
+    </problem>
+    <problem>
+        <file>protectedInFinal.kt</file>
+        <line>4</line>
+        <module>light_idea_test_case</module>
+        <entry_point TYPE="file" FQNAME="temp:///src/protectedInFinal.kt" />
+        <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">'protected' visibility is effectively 'private' in a final class</problem_class>
+        <description>'protected' visibility is effectively 'private' in a final class</description>
+    </problem>
+    <problem>
+        <file>protectedInFinal.kt</file>
+        <line>6</line>
+        <module>light_idea_test_case</module>
+        <entry_point TYPE="file" FQNAME="temp:///src/protectedInFinal.kt" />
+        <problem_class severity="WARNING" attribute_key="WARNING_ATTRIBUTES">'protected' visibility is effectively 'private' in a final class</problem_class>
+        <description>'protected' visibility is effectively 'private' in a final class</description>
+    </problem>
+</problems>

idea/testData/inspections/protectedInFinal/inspectionData/inspections.test

@@ -0,0 +1 @@
+// INSPECTION_CLASS: org.jetbrains.kotlin.idea.inspections.ProtectedInFinalInspection

idea/testData/inspections/protectedInFinal/protectedInFinal.kt

@@ -0,0 +1,37 @@
+class F {
+    protected val foo: Int = 0
+
+    protected fun bar() {}
+
+    protected class Nested
+}
+
+class G {
+    interface H {
+        protected val foo: Int = 0
+
+        protected fun bar() {}
+
+        protected class Nested
+    }
+}
+
+sealed class S {
+    protected val foo: Int = 0
+
+    protected fun bar() {}
+
+    protected class Nested : S()
+
+    protected object Obj : S()
+}
+
+enum class E {
+    SINGLE {
+        override val x = foo()
+    };
+
+    abstract val x: Int
+
+    protected fun foo() = 42
+}