From 00491a78f158063058349a644ea960144f2cfc46 Mon Sep 17 00:00:00 2001
From: Kirill Rakhman <kirill.rakhman@jetbrains.com>
Date: Thu, 4 Jan 2024 10:36:55 +0100
Subject: [PATCH] [FIR] Implement canBeNull for captured type by checking its
 supertypes

#KT-62959
---
 .../jetbrains/kotlin/fir/backend/Fir2IrImplicitCastInserter.kt | 3 +++
 .../providers/src/org/jetbrains/kotlin/fir/types/TypeUtils.kt  | 1 +
 2 files changed, 4 insertions(+)

diff --git a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrImplicitCastInserter.kt b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrImplicitCastInserter.kt
index a0f126a6636..54b9d15e671 100644
--- a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrImplicitCastInserter.kt
+++ b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrImplicitCastInserter.kt
@@ -256,6 +256,9 @@ class Fir2IrImplicitCastInserter(
     }
 
     private fun ConeKotlinType.acceptsNullValues(): Boolean {
+        if (this is ConeCapturedType && this.constructor.projection.kind == ProjectionKind.IN) {
+            return constructor.projection.type!!.canBeNull(session)
+        }
         return canBeNull(session) || hasEnhancedNullability
     }
 
diff --git a/compiler/fir/providers/src/org/jetbrains/kotlin/fir/types/TypeUtils.kt b/compiler/fir/providers/src/org/jetbrains/kotlin/fir/types/TypeUtils.kt
index a9f3ee5bbf7..28ecda80159 100644
--- a/compiler/fir/providers/src/org/jetbrains/kotlin/fir/types/TypeUtils.kt
+++ b/compiler/fir/providers/src/org/jetbrains/kotlin/fir/types/TypeUtils.kt
@@ -821,6 +821,7 @@ fun ConeKotlinType.canBeNull(session: FirSession): Boolean {
             it.coneType.fullyExpandedType(session).canBeNull(session)
         }
         is ConeIntersectionType -> intersectedTypes.all { it.canBeNull(session) }
+        is ConeCapturedType -> constructor.supertypes?.all { it.canBeNull(session) } == true
         else -> fullyExpandedType(session).isNullable
     }
 }