Account for substitutions of one variable for another (it must remain a variable)

compiler/testData/diagnostics/tests/platformTypes/methodCall/visitor.kt

@@ -0,0 +1,23 @@
+// FILE: p/Visitor.java
+
+package p;
+
+public interface Visitor<D> {
+
+}
+
+// FILE: p/Element.java
+
+package p;
+
+public class Element {
+    public <D> R accept(@NotNull Visitor<D> visitor, D data) {return null;}
+}
+
+// FILE: k.kt
+
+import p.*
+
+fun test(v: Visitor<Nothing>, e: Element) {
+    e.accept(v, null)
+}

compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java

@@ -7811,6 +7811,11 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                     doTest(fileName);
                 }
                 
+                @TestMetadata("visitor.kt")
+                public void testVisitor() throws Exception {
+                    doTest("compiler/testData/diagnostics/tests/platformTypes/methodCall/visitor.kt");
+                }
+                
             }
             
         }

core/descriptor.loader.java/src/org/jetbrains/jet/lang/resolve/java/lazy/types/LazyJavaTypeResolver.kt

@@ -264,18 +264,10 @@ class LazyJavaTypeResolver(
         override fun isNullable(): Boolean = _nullable()
     }
 
-    /*
+    private open class FlexibleJavaClassifierType(
-     * For a java type like java.util.List<Foo>
+            lowerBound: JetType,
-     *     lowerBound = MutableList<Foo>
+            upperBound: JetType
-     *     upperBound = List<Foo?>
+    ) : DelegatingFlexibleType(lowerBound, upperBound), CustomTypeVariable {
-     */
-    private inner class LazyFlexibleJavaClassifierType(
-            javaType: JavaClassifierType,
-            attr: JavaTypeAttributes
-    ) : DelegatingFlexibleType(
-            LazyJavaClassifierType(javaType, attr.toFlexible(FLEXIBLE_LOWER_BOUND)),
-            LazyJavaClassifierType(javaType, attr.toFlexible(FLEXIBLE_UPPER_BOUND))
-    ), CustomTypeVariable {
 
         override val isTypeVariable: Boolean = lowerBound.getConstructor() == upperBound.getConstructor()
                                                && lowerBound.getConstructor().getDeclarationDescriptor() is TypeParameterDescriptor
@@ -284,11 +276,22 @@ class LazyJavaTypeResolver(
 
         override fun substitutionResult(replacement: JetType): JetType {
             return if (replacement.isFlexible()) replacement
-                   else DelegatingFlexibleType(TypeUtils.makeNotNullable(replacement), TypeUtils.makeNullable(replacement))
+                   else FlexibleJavaClassifierType(TypeUtils.makeNotNullable(replacement), TypeUtils.makeNullable(replacement))
         }
     }
 
-    private class JavaTypeVariable()
+    /*
+     * For a java type like java.util.List<Foo>
+     *     lowerBound = MutableList<Foo>
+     *     upperBound = List<Foo?>
+     */
+    private inner class LazyFlexibleJavaClassifierType(
+            javaType: JavaClassifierType,
+            attr: JavaTypeAttributes
+    ) : FlexibleJavaClassifierType(
+            LazyJavaClassifierType(javaType, attr.toFlexible(FLEXIBLE_LOWER_BOUND)),
+            LazyJavaClassifierType(javaType, attr.toFlexible(FLEXIBLE_UPPER_BOUND))
+    )
 }
 
 trait JavaTypeAttributes {