Can be private: don't report when object or subclass calls the function

Questionable
So #KT-22030 Fixed

idea/src/org/jetbrains/kotlin/idea/inspections/MemberVisibilityCanBePrivateInspection.kt

@@ -28,23 +28,26 @@ import com.intellij.psi.search.GlobalSearchScope
 import com.intellij.psi.search.PsiSearchHelper
 import com.intellij.psi.search.searches.ReferencesSearch
 import com.intellij.util.Processor
+import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptorWithVisibility
 import org.jetbrains.kotlin.descriptors.EffectiveVisibility
 import org.jetbrains.kotlin.descriptors.effectiveVisibility
 import org.jetbrains.kotlin.idea.core.isInheritable
 import org.jetbrains.kotlin.idea.core.isOverridable
 import org.jetbrains.kotlin.idea.core.toDescriptor
+import org.jetbrains.kotlin.idea.intentions.getCallableDescriptor
 import org.jetbrains.kotlin.idea.quickfix.AddModifierFix
 import org.jetbrains.kotlin.idea.refactoring.isConstructorDeclaredProperty
+import org.jetbrains.kotlin.idea.references.mainReference
 import org.jetbrains.kotlin.idea.search.isCheapEnoughToSearchConsideringOperators
 import org.jetbrains.kotlin.idea.search.usagesSearch.dataClassComponentFunction
+import org.jetbrains.kotlin.idea.search.usagesSearch.descriptor
 import org.jetbrains.kotlin.idea.stubindex.KotlinSourceFilterScope
-import org.jetbrains.kotlin.idea.util.isEffectivelyActual
 import org.jetbrains.kotlin.idea.util.isExpectDeclaration
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.*
-import org.jetbrains.kotlin.resolve.jvm.annotations.hasJvmFieldAnnotation
+import org.jetbrains.kotlin.resolve.DescriptorUtils
 
 class MemberVisibilityCanBePrivateInspection : AbstractKotlinInspection() {
 
@@ -118,20 +121,27 @@ class MemberVisibilityCanBePrivateInspection : AbstractKotlinInspection() {
         ReferencesSearch.search(declaration, restrictedScope).forEach(Processor<PsiReference> {
             val usage = it.element
             if (classOrObject != usage.getParentOfType<KtClassOrObject>(false)) {
+                otherUsageFound = true
+                return@Processor false
+            }
+            val classOrObjectDescriptor = classOrObject.descriptor as? ClassDescriptor
+            if (classOrObjectDescriptor != null) {
+                val receiver = usage.getStrictParentOfType<KtQualifiedExpression>()?.receiverExpression
+                val receiverDescriptor = (receiver?.getCallableDescriptor()?.returnType?.constructor?.declarationDescriptor
+                        ?: (receiver?.mainReference?.resolve() as? KtClassOrObject)?.descriptor) as? ClassDescriptor
+                if (receiverDescriptor != null && DescriptorUtils.isSubclass(receiverDescriptor, classOrObjectDescriptor)) {
+                    otherUsageFound = true
+                    return@Processor false
+                }
+            }
+            val function = usage.getParentOfType<KtCallableDeclaration>(false)
+            val insideInlineFun = function?.modifierList?.let { it.hasModifier(KtTokens.INLINE_KEYWORD) && !function.isPrivate() } ?: false
+            if (insideInlineFun) {
                 otherUsageFound = true
                 false
             } else {
-                val function = usage.getParentOfType<KtCallableDeclaration>(false)
-                val insideInlineFun = function?.modifierList?.let {
-                    it.hasModifier(KtTokens.INLINE_KEYWORD) && !function.isPrivate()
-                } ?: false
-                if (insideInlineFun) {
-                    otherUsageFound = true
-                    false
-                } else {
-                    inClassUsageFound = true
-                    true
-                }
+                inClassUsageFound = true
+                true
             }
         })
         return inClassUsageFound && !otherUsageFound

idea/testData/inspectionsLocal/memberVisibilityCanBePrivate/subClassFunctionCall.kt

@@ -0,0 +1,10 @@
+// PROBLEM: none
+open class A {
+    <caret>internal fun foo() {}
+
+    fun bar(c: C) {
+        c.foo()
+    }
+}
+
+class C : A()

idea/testData/inspectionsLocal/memberVisibilityCanBePrivate/subObjectFunctionCall.kt

@@ -0,0 +1,10 @@
+// PROBLEM: none
+open class A {
+    <caret>internal fun foo() {}
+
+    fun bar() {
+        O.foo()
+    }
+}
+
+object O : A()

idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java

@@ -2548,6 +2548,16 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
         public void testJvmFieldOnProperty() throws Exception {
             runTest("idea/testData/inspectionsLocal/memberVisibilityCanBePrivate/JvmFieldOnProperty.kt");
         }
+
+        @TestMetadata("subClassFunctionCall.kt")
+        public void testSubClassFunctionCall() throws Exception {
+            runTest("idea/testData/inspectionsLocal/memberVisibilityCanBePrivate/subClassFunctionCall.kt");
+        }
+
+        @TestMetadata("subObjectFunctionCall.kt")
+        public void testSubObjectFunctionCall() throws Exception {
+            runTest("idea/testData/inspectionsLocal/memberVisibilityCanBePrivate/subObjectFunctionCall.kt");
+        }
     }
 
     @TestMetadata("idea/testData/inspectionsLocal/migrateDiagnosticSuppression")