Fixed bug with isInitialized for fake overridden properties + test

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/LateinitLowering.kt

@@ -19,6 +19,7 @@ package org.jetbrains.kotlin.backend.konan.lower
 import org.jetbrains.kotlin.backend.common.CommonBackendContext
 import org.jetbrains.kotlin.backend.common.FileLoweringPass
 import org.jetbrains.kotlin.backend.common.lower.*
+import org.jetbrains.kotlin.backend.konan.descriptors.resolveFakeOverride
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.descriptors.VariableDescriptor
 import org.jetbrains.kotlin.ir.IrStatement
@@ -98,7 +99,7 @@ internal class LateinitLowering(
                 val propertyReference = expression.extensionReceiver!! as IrPropertyReference
                 assert(propertyReference.extensionReceiver == null, { "'lateinit' modifier is not allowed on extension properties" })
                 // TODO: Take propertyReference.fieldSymbol as soon as it will show up in IR.
-                val propertyDescriptor = propertyReference.descriptor
+                val propertyDescriptor = propertyReference.descriptor.resolveFakeOverride().original
 
                 val type = propertyDescriptor.type
                 assert(!KotlinBuiltIns.isPrimitiveType(type), { "'lateinit' modifier is not allowed on primitive types" })

backend.native/tests/build.gradle

@@ -1092,6 +1092,11 @@ task lateinit_globalIsInitialized(type: RunKonanTest) {
     source = "codegen/lateinit/globalIsInitialized.kt"
 }
 
+task lateinit_innerIsInitialized(type: RunKonanTest) {
+    goldValue = "OK\n"
+    source = "codegen/lateinit/innerIsInitialized.kt"
+}
+
 task kclass0(type: RunKonanTest) {
     source = "codegen/kclass/kclass0.kt"
 }

backend.native/tests/codegen/lateinit/innerIsInitialized.kt

@@ -0,0 +1,23 @@
+package codegen.lateinit.innerIsInitialized
+
+import kotlin.test.*
+
+open class Foo {
+    lateinit var bar: String
+
+    fun test(): String {
+        return InnerSubclass().testInner()
+    }
+
+    inner class InnerSubclass : Foo() {
+        fun testInner(): String {
+            // This is access to InnerSubclass.bar which is inherited from Foo.bar
+            if (this::bar.isInitialized) return "Fail"
+            return "OK"
+        }
+    }
+}
+
+@Test fun runTest() {
+    println(Foo().test())
+}