From 6c27a4911409660feab78a24c3b332125f4e91ed Mon Sep 17 00:00:00 2001
From: Mikhail Zarechenskiy <mikhail.zarechenskiy@jetbrains.com>
Date: Wed, 6 Dec 2017 16:29:47 +0300
Subject: [PATCH] [NI] Use effective variance for equal approximated type

 It's totally safe from the point of type system and reduces extra `out` projections that can add problems with subtyping
---
 .../src/org/jetbrains/kotlin/types/TypeApproximator.kt     | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/compiler/resolution/src/org/jetbrains/kotlin/types/TypeApproximator.kt b/compiler/resolution/src/org/jetbrains/kotlin/types/TypeApproximator.kt
index 9e73e627277..1e6cd4014fa 100644
--- a/compiler/resolution/src/org/jetbrains/kotlin/types/TypeApproximator.kt
+++ b/compiler/resolution/src/org/jetbrains/kotlin/types/TypeApproximator.kt
@@ -406,7 +406,12 @@ class TypeApproximator {
                         }
                     }
 
-                    newArguments[index] = TypeProjectionImpl(Variance.OUT_VARIANCE, approximatedSuperType)
+                    if (NewKotlinTypeChecker.equalTypes(argumentType, approximatedSuperType)) {
+                        newArguments[index] = approximatedSuperType.asTypeProjection()
+                    }
+                    else {
+                        newArguments[index] = TypeProjectionImpl(Variance.OUT_VARIANCE, approximatedSuperType)
+                    }
                 }
             }
         }