Equality for flexible types

compiler/testData/diagnostics/tests/j+k/SupertypeArgumentsNullability-NotNull-SpecialTypes.kt

@@ -18,6 +18,6 @@ public class Y extends X<String> {
 
 fun main() {
     Y().fooN() : Any
-    Y().barN(<!NULL_FOR_NONNULL_TYPE!>null<!>);
+    Y().barN(null);
 }
 

compiler/testData/diagnostics/tests/j+k/SupertypeArgumentsNullability-NotNull-UserTypes.kt

@@ -18,6 +18,6 @@ public class Y extends X<A> {
 
 fun main() {
     Y().fooN() : Any
-    Y().barN(<!NULL_FOR_NONNULL_TYPE!>null<!>);
+    Y().barN(null);
 }
 

compiler/testData/diagnostics/tests/j+k/SupertypeArgumentsNullability-SpecialTypes.kt

@@ -15,7 +15,7 @@ public class Y extends X<String> {
 // FILE: test.kt
 
 fun main() {
-    Y().foo()<!UNSAFE_CALL!>.<!>length
+    Y().foo().length
     Y().bar(null)
 }
 

compiler/testData/diagnostics/tests/j+k/UnboxingNulls.kt

@@ -9,5 +9,5 @@ package a
 
 fun foo() {
   // If this fails, it means that we have broken the rule that Java returns are always nullable
-  a.Test<Int>().t() <!UNSAFE_INFIX_CALL!>+<!> 1
+  a.Test<Int>().t() + 1
 }

compiler/testData/diagnostics/tests/j+k/kt1431.kt

@@ -13,5 +13,5 @@ package d
 import a.C
 
 fun test() {
-    C.create()<!UNSAFE_CALL!>.<!>foo()
+    C.create().foo()
 }

core/descriptors/src/org/jetbrains/jet/lang/types/checker/TypeCheckingProcedure.java

@@ -69,6 +69,20 @@ public class TypeCheckingProcedure {
     }
 
     public boolean equalTypes(@NotNull JetType type1, @NotNull JetType type2) {
+        if (type1 instanceof FlexibleType) {
+            FlexibleType flexibleType1 = (FlexibleType) type1;
+            if (type2 instanceof FlexibleType) {
+                FlexibleType flexibleType2 = (FlexibleType) type2;
+                return equalTypes(flexibleType1.getLowerBound(), flexibleType2.getLowerBound())
+                        && equalTypes(flexibleType1.getUpperBound(), flexibleType2.getUpperBound());
+            }
+            return equalTypes(flexibleType1.getLowerBound(), type2) || equalTypes(flexibleType1.getUpperBound(), type2);
+        }
+        else if (type2 instanceof FlexibleType) {
+            FlexibleType flexibleType2 = (FlexibleType) type2;
+            return equalTypes(type1, flexibleType2.getLowerBound()) || equalTypes(type1, flexibleType2.getUpperBound());
+        }
+
         if (type1.isNullable() != type2.isNullable()) {
             return false;
         }