From 0120139f9c1ecc01a11569b403f9e8206fcc429a Mon Sep 17 00:00:00 2001
From: Stanislav Erokhin <Stanislav.Erokhin@jetbrains.com>
Date: Wed, 28 Oct 2015 13:08:28 +0300
Subject: [PATCH] Fix for EA-74904.

---
 .../jetbrains/kotlin/types/flexibleTypes.kt   | 24 +++++++++----------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/core/descriptors/src/org/jetbrains/kotlin/types/flexibleTypes.kt b/core/descriptors/src/org/jetbrains/kotlin/types/flexibleTypes.kt
index 5edb6f69227..cfa307ac139 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/types/flexibleTypes.kt
+++ b/core/descriptors/src/org/jetbrains/kotlin/types/flexibleTypes.kt
@@ -129,17 +129,6 @@ public open class DelegatingFlexibleType protected constructor(
         }
     }
 
-    init {
-        if (ASSERTIONS_ENABLED) { // workaround for KT-7540
-            assert (!lowerBound.isFlexible()) { "Lower bound of a flexible type can not be flexible: $lowerBound" }
-            assert (!upperBound.isFlexible()) { "Upper bound of a flexible type can not be flexible: $upperBound" }
-            assert (lowerBound != upperBound) { "Lower and upper bounds are equal: $lowerBound == $upperBound" }
-            assert (KotlinTypeChecker.DEFAULT.isSubtypeOf(lowerBound, upperBound)) {
-                "Lower bound $lowerBound of a flexible type must be a subtype of the upper bound $upperBound"
-            }
-        }
-    }
-
     override fun <T : TypeCapability> getCapability(capabilityClass: Class<T>): T? {
         val extra = extraCapabilities.getCapability(capabilityClass, this, this)
         if (extra != null) return extra
@@ -161,7 +150,18 @@ public open class DelegatingFlexibleType protected constructor(
 
     override fun isMarkedNullable(): Boolean = getCapability(javaClass<NullAwareness>())!!.computeIsNullable()
 
-    override val delegateType: KotlinType = lowerBound
+    override val delegateType: KotlinType by lazy {
+            // we can't check this in init block, because lowerBound & upperBound can be LazyType. see EA-74904
+            if (ASSERTIONS_ENABLED) { // workaround for KT-7540
+                assert (!lowerBound.isFlexible()) { "Lower bound of a flexible type can not be flexible: $lowerBound" }
+                assert (!upperBound.isFlexible()) { "Upper bound of a flexible type can not be flexible: $upperBound" }
+                assert (lowerBound != upperBound) { "Lower and upper bounds are equal: $lowerBound == $upperBound" }
+                assert (KotlinTypeChecker.DEFAULT.isSubtypeOf(lowerBound, upperBound)) {
+                    "Lower bound $lowerBound of a flexible type must be a subtype of the upper bound $upperBound"
+                }
+            }
+            lowerBound
+        }
 
     override fun getDelegate() = getCapability(javaClass<FlexibleTypeDelegation>())!!.delegateType