From 225e03aeebf052db184d7cf6afb504637c551057 Mon Sep 17 00:00:00 2001
From: Mario Bucev <mario.bucev@epfl.ch>
Date: Sun, 1 Aug 2021 16:29:09 +0200
Subject: [PATCH] Employ frozen_<:< instead of <:< within EtaExpansion
 extractor logic

---
 compiler/src/dotty/tools/dotc/core/TypeApplications.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compiler/src/dotty/tools/dotc/core/TypeApplications.scala b/compiler/src/dotty/tools/dotc/core/TypeApplications.scala
index aa380b574b98..bc7970d423f5 100644
--- a/compiler/src/dotty/tools/dotc/core/TypeApplications.scala
+++ b/compiler/src/dotty/tools/dotc/core/TypeApplications.scala
@@ -53,7 +53,7 @@ object TypeApplications {
       || {
         val paramRefs = tparams.map(_.paramRef)
         tp.typeParams.corresponds(tparams) { (param1, param2) =>
-          param2.paramInfo <:< param1.paramInfo.substParams(tp, paramRefs)
+          param2.paramInfo frozen_<:< param1.paramInfo.substParams(tp, paramRefs)
         }
       }