From 8a81a09fd0423e4b99c964ecc53b3645b5fedb53 Mon Sep 17 00:00:00 2001
From: Dmitriy Novozhilov <dmitriy.novozhilov@jetbrains.com>
Date: Tue, 16 Jun 2020 12:18:07 +0300
Subject: [PATCH] [FIR] Assume that when without branches is not exhaustive.
 KT-39621

---
 .../resolve/transformers/FirWhenExhaustivenessTransformer.kt    | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirWhenExhaustivenessTransformer.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirWhenExhaustivenessTransformer.kt
index 959b18eb580..50989b731d6 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirWhenExhaustivenessTransformer.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirWhenExhaustivenessTransformer.kt
@@ -58,6 +58,8 @@ class FirWhenExhaustivenessTransformer(private val bodyResolveComponents: BodyRe
                 checkBooleanExhaustiveness(whenExpression, nullable)
             }
 
+            whenExpression.branches.isEmpty() -> false
+
             else -> {
                 val klass = lookupTag.toSymbol(bodyResolveComponents.session)?.fir as? FirRegularClass ?: return null
                 when {