From 11a3126c8ce0860480efe756cf6344e0675e1fc4 Mon Sep 17 00:00:00 2001
From: Ilya Kirillov <ilya.kirillov@jetbrains.com>
Date: Mon, 11 Jan 2021 22:18:44 +0100
Subject: [PATCH] FIR: copy class supertypes list on iterating while
 calculating supertypes

This list is backed by mutable list and during iterating on it
we can resolve supertypes of that class via IDE light classes
as IJ Java resolve may resolve a lot of stuff by fir light classes
This causes ConcurrentModificationException
---
 .../kotlin/fir/resolve/transformers/FirSupertypesResolution.kt  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirSupertypesResolution.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirSupertypesResolution.kt
index 7a10ae85036..a583654d320 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirSupertypesResolution.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirSupertypesResolution.kt
@@ -282,7 +282,7 @@ private class FirSupertypeResolverVisitor(
         supertypeRefs: List<FirTypeRef>
     ): List<FirTypeRef> {
         return resolveSpecificClassLikeSupertypes(classLikeDeclaration) { transformer, scope ->
-            supertypeRefs.mapTo(mutableListOf()) {
+            ArrayList(supertypeRefs).mapTo(mutableListOf()) {
                 val superTypeRef = transformer.transformTypeRef(it, scope).single
 
                 if (superTypeRef.coneTypeSafe<ConeTypeParameterType>() != null)