From 0634782e47b4c76678562b2bc1675368a3f6d63d Mon Sep 17 00:00:00 2001
From: Alexander Udalov <Alexander.Udalov@jetbrains.com>
Date: Tue, 13 Dec 2016 21:05:04 +0300
Subject: [PATCH] Allow open impl class for final header class

---
 .../checkers/HeaderImplDeclarationChecker.kt  |  3 +-
 .../headerClass/implOpenClass.kt              | 16 ++++++++++
 .../headerClass/implOpenClass.txt             | 31 +++++++++++++++++++
 .../checkers/DiagnosticsTestGenerated.java    |  6 ++++
 4 files changed, 55 insertions(+), 1 deletion(-)
 create mode 100644 compiler/testData/diagnostics/tests/multiplatform/headerClass/implOpenClass.kt
 create mode 100644 compiler/testData/diagnostics/tests/multiplatform/headerClass/implOpenClass.txt

diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/HeaderImplDeclarationChecker.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/HeaderImplDeclarationChecker.kt
index 76c5a9bd21c..65f42bac3ba 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/HeaderImplDeclarationChecker.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/HeaderImplDeclarationChecker.kt
@@ -319,7 +319,8 @@ class HeaderImplDeclarationChecker(val moduleToCheck: ModuleDescriptor? = null)
 
         val substitutor = Substitutor(aTypeParams, bTypeParams, parentSubstitutor)
 
-        if (a.modality != b.modality) return Incompatible.Modality
+        if (a.modality != b.modality && !(a.modality == Modality.FINAL && b.modality == Modality.OPEN)) return Incompatible.Modality
+
         if (a.visibility != b.visibility) return Incompatible.Visibility
 
         areCompatibleTypeParameters(aTypeParams, bTypeParams, substitutor).let { if (it != Compatible) return it }
diff --git a/compiler/testData/diagnostics/tests/multiplatform/headerClass/implOpenClass.kt b/compiler/testData/diagnostics/tests/multiplatform/headerClass/implOpenClass.kt
new file mode 100644
index 00000000000..77cf7fd386e
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/multiplatform/headerClass/implOpenClass.kt
@@ -0,0 +1,16 @@
+// !LANGUAGE: +MultiPlatformProjects
+// MODULE: m1-common
+// FILE: common.kt
+
+header class Foo
+
+header fun getFoo(): Foo
+
+// MODULE: m2-jvm(m1-common)
+// FILE: jvm.kt
+
+impl open class Foo
+
+class Bar : Foo()
+
+impl fun getFoo(): Foo = Bar()
diff --git a/compiler/testData/diagnostics/tests/multiplatform/headerClass/implOpenClass.txt b/compiler/testData/diagnostics/tests/multiplatform/headerClass/implOpenClass.txt
new file mode 100644
index 00000000000..62872669be1
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/multiplatform/headerClass/implOpenClass.txt
@@ -0,0 +1,31 @@
+// -- Module: <m1-common> --
+package
+
+public header fun getFoo(): Foo
+
+public final header class Foo {
+    public constructor Foo()
+    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
+}
+
+
+// -- Module: <m2-jvm> --
+package
+
+public impl fun getFoo(): Foo
+
+public final class Bar : Foo {
+    public constructor Bar()
+    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 impl class Foo {
+    public constructor Foo()
+    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
+}
diff --git a/compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java
index 796f6ee32a7..3682bbf8707 100644
--- a/compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java
@@ -13098,6 +13098,12 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                     doTest(fileName);
                 }
 
+                @TestMetadata("implOpenClass.kt")
+                public void testImplOpenClass() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/multiplatform/headerClass/implOpenClass.kt");
+                    doTest(fileName);
+                }
+
                 @TestMetadata("simpleHeaderClass.kt")
                 public void testSimpleHeaderClass() throws Exception {
                     String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/multiplatform/headerClass/simpleHeaderClass.kt");