From ef4c3bdae8e5660e44e4b9756e99fc34c8f94b6d Mon Sep 17 00:00:00 2001
From: Dmitry Petrov <Dmitry.Petrov@jetbrains.com>
Date: Tue, 7 Jun 2016 15:10:22 +0300
Subject: [PATCH] Don't expand types that don't contain type aliases or type
 parameters.

---
 .../kotlin/resolve/TypeAliasExpander.kt        |  5 +++++
 .../kotlin/resolve/TypeAliasExpansion.kt       | 18 ++++++++++++++----
 .../typealias/boundsViolationInTypeAliasRHS.kt |  4 ++--
 3 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/TypeAliasExpander.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/TypeAliasExpander.kt
index 96d8b3f26d7..443d44c41d2 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/TypeAliasExpander.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/TypeAliasExpander.kt
@@ -112,6 +112,11 @@ class TypeAliasExpander(
             recursionDepth: Int
     ): TypeProjection {
         val type = originalProjection.type
+
+        if (!type.requiresTypeAliasExpansion()) {
+            return originalProjection
+        }
+
         val typeConstructor = type.constructor
         val typeDescriptor = typeConstructor.declarationDescriptor
 
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/TypeAliasExpansion.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/TypeAliasExpansion.kt
index 8b68e51c150..a58ca27c061 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/TypeAliasExpansion.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/TypeAliasExpansion.kt
@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.resolve
 
+import org.jetbrains.kotlin.descriptors.ClassifierDescriptor
 import org.jetbrains.kotlin.descriptors.TypeAliasDescriptor
 import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor
 import org.jetbrains.kotlin.types.KotlinType
@@ -57,7 +58,16 @@ class TypeAliasExpansion private constructor(
 }
 
 fun KotlinType.dependsOnTypeAliasParameters(): Boolean =
-        TypeUtils.contains(this) { type ->
-            val constructorDeclaration = type.constructor.declarationDescriptor
-            constructorDeclaration is TypeParameterDescriptor && constructorDeclaration.containingDeclaration is TypeAliasDescriptor
-        }
\ No newline at end of file
+        TypeUtils.contains(this) {
+            it.constructor.declarationDescriptor?.isTypeAliasParameter() ?: false
+        }
+
+fun ClassifierDescriptor.isTypeAliasParameter(): Boolean =
+        this is TypeParameterDescriptor && containingDeclaration is TypeAliasDescriptor
+
+fun KotlinType.requiresTypeAliasExpansion(): Boolean =
+        TypeUtils.contains(this) {
+            it.constructor.declarationDescriptor?.let {
+                it is TypeAliasDescriptor || it is TypeParameterDescriptor
+            }
+        }
diff --git a/compiler/testData/diagnostics/tests/typealias/boundsViolationInTypeAliasRHS.kt b/compiler/testData/diagnostics/tests/typealias/boundsViolationInTypeAliasRHS.kt
index af9f7335965..003d367dc6a 100644
--- a/compiler/testData/diagnostics/tests/typealias/boundsViolationInTypeAliasRHS.kt
+++ b/compiler/testData/diagnostics/tests/typealias/boundsViolationInTypeAliasRHS.kt
@@ -5,8 +5,8 @@ class TColl<T, C : Collection<T>>
 typealias TCErr = TColl<String, <!UPPER_BOUND_VIOLATED!>Any<!>>
 typealias TCErr2 = TCErr
 
-fun testType1(x: <!UPPER_BOUND_VIOLATED_IN_TYPEALIAS_EXPANSION!>TCErr<!>) {}
+fun testType1(x: TCErr) {}
 val testCtor1 = <!UPPER_BOUND_VIOLATED_IN_TYPEALIAS_EXPANSION!>TCErr()<!>
 
-fun testType2(x: <!UPPER_BOUND_VIOLATED_IN_TYPEALIAS_EXPANSION!>TCErr2<!>) {}
+fun testType2(x: TCErr2) {}
 val testCtor2 = <!UPPER_BOUND_VIOLATED_IN_TYPEALIAS_EXPANSION!>TCErr2()<!>