KT-3302 Method that implements two differing interfaces are reported as "Incompatible types in superclasses"

#KT-3302 fixed

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/kotlinSignature/SignaturesPropagationData.java

@@ -17,6 +17,7 @@
 package org.jetbrains.jet.lang.resolve.java.kotlinSignature;
 
 import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
 import com.google.common.collect.Multimap;
 import com.google.common.collect.Sets;
 import com.intellij.openapi.application.ApplicationManager;
@@ -200,6 +201,9 @@ public class SignaturesPropagationData {
             @NotNull ClassDescriptor containingClass
     ) {
         List<FunctionDescriptor> superFunctions = Lists.newArrayList();
+
+        Map<ClassDescriptor, JetType> superclassToSupertype = getSuperclassToSupertypeMap(containingClass);
+
         for (HierarchicalMethodSignature superSignature : method.getPsiMethod().getHierarchicalMethodSignature().getSuperSignatures()) {
             PsiMethod superMethod = superSignature.getMethod();
 
@@ -222,7 +226,18 @@ public class SignaturesPropagationData {
             }
 
             assert superFun instanceof FunctionDescriptor : superFun.getClass().getName();
-            superFunctions.add((FunctionDescriptor) superFun);
+
+            DeclarationDescriptor superFunContainer = superFun.getContainingDeclaration();
+            assert superFunContainer instanceof ClassDescriptor: superFunContainer;
+
+            JetType supertype = superclassToSupertype.get(superFunContainer);
+            assert supertype != null : "Couldn't find super type for super function: " + superFun;
+            TypeSubstitutor supertypeSubstitutor = TypeSubstitutor.create(supertype);
+
+            FunctionDescriptor substitutedSuperFun = ((FunctionDescriptor) superFun).substitute(supertypeSubstitutor);
+            assert substitutedSuperFun != null;
+
+            superFunctions.add(substitutedSuperFun);
         }
 
         // sorting for diagnostic stability
@@ -560,6 +575,16 @@ public class SignaturesPropagationData {
         return classifier;
     }
 
+    private static Map<ClassDescriptor, JetType> getSuperclassToSupertypeMap(ClassDescriptor containingClass) {
+        Map<ClassDescriptor, JetType> superclassToSupertype = Maps.newHashMap();
+        for (JetType supertype : TypeUtils.getAllSupertypes(containingClass.getDefaultType())) {
+            ClassifierDescriptor superclass = supertype.getConstructor().getDeclarationDescriptor();
+            assert superclass instanceof ClassDescriptor;
+            superclassToSupertype.put((ClassDescriptor) superclass, supertype);
+        }
+        return superclassToSupertype;
+    }
+
     private static boolean isArrayType(@NotNull JetType type) {
         KotlinBuiltIns builtIns = KotlinBuiltIns.getInstance();
         return builtIns.isArray(type) || builtIns.isPrimitiveArray(type);