From 1c7ffb32763de3fd7b685421aeb935bd57e2ff5e Mon Sep 17 00:00:00 2001
From: Mikhail Glukhikh <mikhail.glukhikh@jetbrains.com>
Date: Wed, 3 May 2023 11:09:32 +0200
Subject: [PATCH] ResultTypeResolver: don't allow Nothing as ILT subtype

#KT-58379 Fixed
---
 .../components/ResultTypeResolver.kt          |  5 ++--
 .../tests/integerLiterals/sortedBy.fir.kt     | 25 -------------------
 .../tests/integerLiterals/sortedBy.kt         |  1 +
 3 files changed, 4 insertions(+), 27 deletions(-)
 delete mode 100644 compiler/testData/diagnostics/tests/integerLiterals/sortedBy.fir.kt

diff --git a/compiler/resolution.common/src/org/jetbrains/kotlin/resolve/calls/inference/components/ResultTypeResolver.kt b/compiler/resolution.common/src/org/jetbrains/kotlin/resolve/calls/inference/components/ResultTypeResolver.kt
index c35fbcb1a5d..97e7ef3644a 100644
--- a/compiler/resolution.common/src/org/jetbrains/kotlin/resolve/calls/inference/components/ResultTypeResolver.kt
+++ b/compiler/resolution.common/src/org/jetbrains/kotlin/resolve/calls/inference/components/ResultTypeResolver.kt
@@ -94,12 +94,13 @@ class ResultTypeResolver(
         // and the second one from UPPER/LOWER constraints (subType/superType based)
         // The logic of choice here is:
         // - if one type is null, we return another one
-        // - we return type from UPPER/LOWER constraints if it's more precise
+        // - we return type from UPPER/LOWER constraints if it's more precise (in fact, only Int/Short/Byte/Long is allowed here)
         // - otherwise we return ILT-based type
         return when {
             resultTypeFromEqualConstraint == null -> resultTypeFromDirection
             resultTypeFromDirection == null -> resultTypeFromEqualConstraint
-            AbstractTypeChecker.isSubtypeOf(c, resultTypeFromDirection, resultTypeFromEqualConstraint) -> resultTypeFromDirection
+            with(c) { !resultTypeFromDirection.typeConstructor().isNothingConstructor() } &&
+                    AbstractTypeChecker.isSubtypeOf(c, resultTypeFromDirection, resultTypeFromEqualConstraint) -> resultTypeFromDirection
             else -> resultTypeFromEqualConstraint
         }
     }
diff --git a/compiler/testData/diagnostics/tests/integerLiterals/sortedBy.fir.kt b/compiler/testData/diagnostics/tests/integerLiterals/sortedBy.fir.kt
deleted file mode 100644
index 2acb420d209..00000000000
--- a/compiler/testData/diagnostics/tests/integerLiterals/sortedBy.fir.kt
+++ /dev/null
@@ -1,25 +0,0 @@
-// WITH_STDLIB
-
-import Cause.*
-
-typealias ChallengeFunction = suspend (String) -> Unit
-
-enum class Cause {
-    FIRST,
-    SECOND,
-    ERROR,
-    LAST
-}
-
-class Some {
-    internal val register = mutableListOf<Pair<Cause, ChallengeFunction>>()
-
-    internal val challenges: List<ChallengeFunction>
-        get() = <!NEW_INFERENCE_ERROR!>register.filter { it.first != ERROR }.sortedBy {
-            when (it.first) {
-                FIRST -> 1
-                SECOND -> 2
-                else -> throw AssertionError()
-            }
-        }<!>.map { it.second }
-}
diff --git a/compiler/testData/diagnostics/tests/integerLiterals/sortedBy.kt b/compiler/testData/diagnostics/tests/integerLiterals/sortedBy.kt
index ffe81162456..f99cfbfc135 100644
--- a/compiler/testData/diagnostics/tests/integerLiterals/sortedBy.kt
+++ b/compiler/testData/diagnostics/tests/integerLiterals/sortedBy.kt
@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // WITH_STDLIB
 
 import Cause.*