From 98bd6f5d3eac4b87658ec229fb9e85b34cbe10c7 Mon Sep 17 00:00:00 2001
From: Mikhail Glukhikh <mikhail.glukhikh@jetbrains.com>
Date: Mon, 26 Jul 2021 10:13:13 +0300
Subject: [PATCH] Fix "implicit type" exception in FIR OptIn checker

---
 .../analysis/checkers/expression/FirOptInUsageBaseChecker.kt   | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/expression/FirOptInUsageBaseChecker.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/expression/FirOptInUsageBaseChecker.kt
index d827b67449f..92af4640d5b 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/expression/FirOptInUsageBaseChecker.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/expression/FirOptInUsageBaseChecker.kt
@@ -110,7 +110,8 @@ object FirOptInUsageBaseChecker {
                 }
             }
             if (fir !is FirConstructor) {
-                fir.returnTypeRef.coneType.addExperimentalities(context, result, visited)
+                // Without coneTypeSafe v fails in MT test (FirRenderer.kt)
+                fir.returnTypeRef.coneTypeSafe<ConeKotlinType>().addExperimentalities(context, result, visited)
                 fir.receiverTypeRef?.coneType.addExperimentalities(context, result, visited)
                 if (fir is FirSimpleFunction) {
                     fir.valueParameters.forEach {