From c64cb06180d7c0d628005a97d7d1490418c7d536 Mon Sep 17 00:00:00 2001
From: Evgeny Gerashchenko <Evgeny.Gerashchenko@jetbrains.com>
Date: Mon, 12 Jan 2015 19:21:48 +0300
Subject: [PATCH] KT-6530 Do not report "useless cast" when RHS is unresolved

 #KT-6530 fixed
---
 .../kotlin/types/expressions/BasicExpressionTypingVisitor.java  | 2 +-
 compiler/testData/diagnostics/tests/Casts.kt                    | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/compiler/frontend/src/org/jetbrains/kotlin/types/expressions/BasicExpressionTypingVisitor.java b/compiler/frontend/src/org/jetbrains/kotlin/types/expressions/BasicExpressionTypingVisitor.java
index fb8f34b2523..d75ab1ddf36 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/types/expressions/BasicExpressionTypingVisitor.java
+++ b/compiler/frontend/src/org/jetbrains/kotlin/types/expressions/BasicExpressionTypingVisitor.java
@@ -205,7 +205,7 @@ public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
             JetType targetType,
             ExpressionTypingContext context
     ) {
-        if (actualType == null || noExpectedType(targetType)) return;
+        if (actualType == null || noExpectedType(targetType) || targetType.isError()) return;
 
         if (TypesPackage.isDynamic(targetType)) {
             JetTypeReference right = expression.getRight();
diff --git a/compiler/testData/diagnostics/tests/Casts.kt b/compiler/testData/diagnostics/tests/Casts.kt
index 3811dfe4cfa..ce582bc9006 100644
--- a/compiler/testData/diagnostics/tests/Casts.kt
+++ b/compiler/testData/diagnostics/tests/Casts.kt
@@ -13,4 +13,6 @@ fun test() : Unit {
   x <!USELESS_CAST!>as? Int?<!> : Int?
   y <!USELESS_CAST_STATIC_ASSERT_IS_FINE!>as? Int?<!> : Int?
   Unit
+
+  x as <!UNRESOLVED_REFERENCE!>UnresolvedType<!>
 }