FIR2IR: correct base symbols of fake overrides for delegated member

#KT-43984 Fixed

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/FakeOverrideGenerator.kt

@@ -10,11 +10,9 @@ import org.jetbrains.kotlin.fir.*
 import org.jetbrains.kotlin.fir.backend.*
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.resolve.defaultType
-import org.jetbrains.kotlin.fir.scopes.FirTypeScope
-import org.jetbrains.kotlin.fir.scopes.getDirectOverriddenFunctions
-import org.jetbrains.kotlin.fir.scopes.getDirectOverriddenProperties
+import org.jetbrains.kotlin.fir.scopes.*
 import org.jetbrains.kotlin.fir.scopes.impl.FirFakeOverrideGenerator
-import org.jetbrains.kotlin.fir.scopes.unsubstitutedScope
+import org.jetbrains.kotlin.fir.scopes.impl.delegatedWrapperData
 import org.jetbrains.kotlin.fir.symbols.AbstractFirBasedSymbol
 import org.jetbrains.kotlin.fir.symbols.ConeClassLikeLookupTag
 import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
@@ -194,11 +192,13 @@ class FakeOverrideGenerator(
     ): List<S> {
         if (symbol.fir.origin != FirDeclarationOrigin.IntersectionOverride) return listOf(basedSymbol)
         return scope.directOverridden(symbol).map {
-            @Suppress("UNCHECKED_CAST")
-            if (it.fir.isSubstitutionOverride && it.dispatchReceiverClassOrNull() == containingClass)
-                it.originalForSubstitutionOverride!!
-            else
-                it
+            when {
+                it.fir.isSubstitutionOverride && it.dispatchReceiverClassOrNull() == containingClass ->
+                    it.originalForSubstitutionOverride!!
+                it.fir.origin == FirDeclarationOrigin.Delegated ->
+                    it.fir.delegatedWrapperData?.wrapped?.symbol!! as S
+                else -> it
+            }
         }
     }
 

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/codegen/ir/FirBlackBoxAgainstJavaCodegenTestGenerated.java

@@ -425,6 +425,11 @@ public class FirBlackBoxAgainstJavaCodegenTestGenerated extends AbstractFirBlack
             KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/boxAgainstJava/interfaces"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
         }
 
+        @TestMetadata("defaultMethod.kt")
+        public void testDefaultMethod() throws Exception {
+            runTest("compiler/testData/codegen/boxAgainstJava/interfaces/defaultMethod.kt");
+        }
+
         @TestMetadata("inheritJavaInterface.kt")
         public void testInheritJavaInterface() throws Exception {
             runTest("compiler/testData/codegen/boxAgainstJava/interfaces/inheritJavaInterface.kt");

compiler/testData/codegen/boxAgainstJava/interfaces/defaultMethod.kt

@@ -0,0 +1,22 @@
+// JVM_TARGET: 1.8
+
+// FILE: A.java
+
+public interface A {
+    default String getMessage() {
+        return "OK";
+    }
+}
+
+// FILE: 1.kt
+
+interface I : A
+
+class B : A
+
+open class C(a : A) : I, A by a
+
+fun box(): String {
+    val a = B()
+    return C(a).message
+}

compiler/tests-gen/org/jetbrains/kotlin/codegen/BlackBoxAgainstJavaCodegenTestGenerated.java

@@ -424,6 +424,11 @@ public class BlackBoxAgainstJavaCodegenTestGenerated extends AbstractBlackBoxAga
             KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/boxAgainstJava/interfaces"), Pattern.compile("^(.+)\\.kt$"), null, true);
         }
 
+        @TestMetadata("defaultMethod.kt")
+        public void testDefaultMethod() throws Exception {
+            runTest("compiler/testData/codegen/boxAgainstJava/interfaces/defaultMethod.kt");
+        }
+
         @TestMetadata("inheritJavaInterface.kt")
         public void testInheritJavaInterface() throws Exception {
             runTest("compiler/testData/codegen/boxAgainstJava/interfaces/inheritJavaInterface.kt");

compiler/tests-gen/org/jetbrains/kotlin/codegen/ir/IrBlackBoxAgainstJavaCodegenTestGenerated.java

@@ -425,6 +425,11 @@ public class IrBlackBoxAgainstJavaCodegenTestGenerated extends AbstractIrBlackBo
             KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/boxAgainstJava/interfaces"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
         }
 
+        @TestMetadata("defaultMethod.kt")
+        public void testDefaultMethod() throws Exception {
+            runTest("compiler/testData/codegen/boxAgainstJava/interfaces/defaultMethod.kt");
+        }
+
         @TestMetadata("inheritJavaInterface.kt")
         public void testInheritJavaInterface() throws Exception {
             runTest("compiler/testData/codegen/boxAgainstJava/interfaces/inheritJavaInterface.kt");