From 5283f7b7c67fe7d196432e915e425f581a23e37e Mon Sep 17 00:00:00 2001
From: Mikhail Glukhikh <mikhail.glukhikh@jetbrains.com>
Date: Fri, 30 Jul 2021 17:37:45 +0300
Subject: [PATCH] Make EXPERIMENTAL_API_USAGE_ERR warning till 1.6 for fake
 override case

---
 .../kotlin/resolve/checkers/ExperimentalUsageChecker.kt    | 7 ++++++-
 .../testsWithStdLib/experimental/implicitUsagesFuture.kt   | 2 +-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/ExperimentalUsageChecker.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/ExperimentalUsageChecker.kt
index aca457d393a..1442d438eee 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/ExperimentalUsageChecker.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/ExperimentalUsageChecker.kt
@@ -176,7 +176,12 @@ class ExperimentalUsageChecker(project: Project) : CallChecker {
             val result = SmartSet.create<Experimentality>()
             if (this is CallableMemberDescriptor && kind == CallableMemberDescriptor.Kind.FAKE_OVERRIDE) {
                 for (overridden in overriddenDescriptors) {
-                    result.addAll(overridden.loadExperimentalities(moduleAnnotationsResolver, languageVersionSettings, visited, useFutureError))
+                    result.addAll(overridden.loadExperimentalities(
+                        moduleAnnotationsResolver,
+                        languageVersionSettings,
+                        visited,
+                        useFutureError = !languageVersionSettings.supportsFeature(LanguageFeature.OptInContagiousSignatures)
+                    ))
                 }
                 return result
             }
diff --git a/compiler/testData/diagnostics/testsWithStdLib/experimental/implicitUsagesFuture.kt b/compiler/testData/diagnostics/testsWithStdLib/experimental/implicitUsagesFuture.kt
index 5b18aeeb765..3635d075a13 100644
--- a/compiler/testData/diagnostics/testsWithStdLib/experimental/implicitUsagesFuture.kt
+++ b/compiler/testData/diagnostics/testsWithStdLib/experimental/implicitUsagesFuture.kt
@@ -49,7 +49,7 @@ interface NotExperimentalExtension : ExperimentalType {
 
 fun use(arg: NotExperimentalExtension) {
     arg.foo()
-    arg.<!EXPERIMENTAL_API_USAGE_ERROR!>bar<!>()
+    arg.<!EXPERIMENTAL_API_USAGE_FUTURE_ERROR!>bar<!>()
 }
 
 @Marker