From 35a29acdc78e3a4d35138cc1dc9c0755e14e6182 Mon Sep 17 00:00:00 2001
From: "sebastian.sellmair" <sebastian.sellmair@jetbrains.com>
Date: Fri, 10 Sep 2021 14:34:01 +0200
Subject: [PATCH] [Commonizer] Always use parent arguments for type
 substitution

---
 .../jetbrains/kotlin/commonizer/cir/utils.kt  |  6 +++-
 .../core/ClassOrTypeAliasTypeCommonizer.kt    |  2 +-
 ...icalOptimisticNumbersTypeCommonizerTest.kt |  2 +-
 .../HierarchicalTypeAliasCommonizationTest.kt | 36 +++++++++++++++++++
 4 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/native/commonizer/src/org/jetbrains/kotlin/commonizer/cir/utils.kt b/native/commonizer/src/org/jetbrains/kotlin/commonizer/cir/utils.kt
index 67b88d720e1..91d5b413a1d 100644
--- a/native/commonizer/src/org/jetbrains/kotlin/commonizer/cir/utils.kt
+++ b/native/commonizer/src/org/jetbrains/kotlin/commonizer/cir/utils.kt
@@ -95,6 +95,10 @@ internal fun CirClassOrTypeAliasType.withParentArguments(
         if (oldArgument is CirRegularTypeProjection) {
             val oldArgumentType = oldArgument.type
             if (oldArgumentType is CirTypeParameterType) {
+                when (val parentArgument = parentArguments[oldArgumentType.index]) {
+                    is CirRegularTypeProjection -> if (parentArgument is CirClassOrTypeAliasType) return@map parentArgument
+                    is CirStarTypeProjection -> return@map parentArgument
+                }
                 return@map parentArguments[oldArgumentType.index]
             }
         }
@@ -105,7 +109,7 @@ internal fun CirClassOrTypeAliasType.withParentArguments(
         this -> this
         is CirClassType -> newUnderlyingType
         is CirTypeAliasType -> newUnderlyingType.withUnderlyingType(
-            newUnderlyingType.underlyingType.withParentArguments(newArguments, newIsMarkedNullable)
+            newUnderlyingType.underlyingType.withParentArguments(parentArguments, newIsMarkedNullable)
         )
     }
 }
diff --git a/native/commonizer/src/org/jetbrains/kotlin/commonizer/core/ClassOrTypeAliasTypeCommonizer.kt b/native/commonizer/src/org/jetbrains/kotlin/commonizer/core/ClassOrTypeAliasTypeCommonizer.kt
index 9cbaef4a06f..c7f7b704820 100644
--- a/native/commonizer/src/org/jetbrains/kotlin/commonizer/core/ClassOrTypeAliasTypeCommonizer.kt
+++ b/native/commonizer/src/org/jetbrains/kotlin/commonizer/core/ClassOrTypeAliasTypeCommonizer.kt
@@ -113,7 +113,7 @@ internal class ClassOrTypeAliasTypeCommonizer(
 
             /* Only forward substitutions allowed -> Only substitute with any underlying type */
             forwardSubstitutionAllowed -> commonId.aliases.filter { candidate ->
-                types.all { type -> type.isAnyUnderlyingClassifier(candidate) }
+                types.all { type -> candidate == type.classifierId || type.isAnyUnderlyingClassifier(candidate) }
             }
 
             /* Only backward substitutions allowed -> Only substitute with any typealias pointing to this types */
diff --git a/native/commonizer/tests/org/jetbrains/kotlin/commonizer/hierarchical/HierarchicalOptimisticNumbersTypeCommonizerTest.kt b/native/commonizer/tests/org/jetbrains/kotlin/commonizer/hierarchical/HierarchicalOptimisticNumbersTypeCommonizerTest.kt
index f12ac9722b3..4d9ba4608f5 100644
--- a/native/commonizer/tests/org/jetbrains/kotlin/commonizer/hierarchical/HierarchicalOptimisticNumbersTypeCommonizerTest.kt
+++ b/native/commonizer/tests/org/jetbrains/kotlin/commonizer/hierarchical/HierarchicalOptimisticNumbersTypeCommonizerTest.kt
@@ -618,7 +618,7 @@ class HierarchicalOptimisticNumbersTypeCommonizerTest : AbstractInlineSourcesCom
                 @UnsafeNumber(["a: kotlin.Int", "b: kotlin.Long"])
                 typealias B = A
                 @UnsafeNumber(["a: kotlin.Int", "b: kotlin.Long"])
-                typealias X = A
+                typealias X = B
             """.trimIndent()
         )
     }
diff --git a/native/commonizer/tests/org/jetbrains/kotlin/commonizer/hierarchical/HierarchicalTypeAliasCommonizationTest.kt b/native/commonizer/tests/org/jetbrains/kotlin/commonizer/hierarchical/HierarchicalTypeAliasCommonizationTest.kt
index a33c917543f..8f8e0a311c7 100644
--- a/native/commonizer/tests/org/jetbrains/kotlin/commonizer/hierarchical/HierarchicalTypeAliasCommonizationTest.kt
+++ b/native/commonizer/tests/org/jetbrains/kotlin/commonizer/hierarchical/HierarchicalTypeAliasCommonizationTest.kt
@@ -162,4 +162,40 @@ class HierarchicalTypeAliasCommonizationTest : AbstractInlineSourcesCommonizatio
             """.trimIndent()
         )
     }
+
+    fun `test typealias with phantom type`() {
+        val result = commonize {
+            outputTarget("(a, b)")
+
+            simpleSingleSourceTarget(
+                "a", """
+                    typealias A<N, M> = Map<N, M>
+                    typealias B<N, Phantom, M> = A<N, M>
+                    typealias X<T> = B<T, String, Long>
+                    
+                    fun x(x: X<Int>) = Unit
+                """.trimIndent()
+            )
+
+            simpleSingleSourceTarget(
+                "b", """
+                    typealias A<N, M> = Map<N, M>
+                    typealias B<N, Phantom, M> = A<N, M>
+                    typealias X<T> = B<T, String, Long>
+                    typealias Y<T> = X<T>
+                    fun x(x: Y<Int>) = Unit
+                """.trimIndent()
+            )
+        }
+
+        result.assertCommonized(
+            "(a, b)", """
+                typealias A<N, M> = Map<N, M>
+                typealias B<N, Phantom, M> = A<N, M>
+                typealias X<T> = B<T, String, Long>
+                
+                expect fun x(x: X<Int>)
+            """.trimIndent()
+        )
+    }
 }