A clarifying assertion

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaDescriptorResolver.java

@@ -1020,6 +1020,9 @@ public class JavaDescriptorResolver implements DependencyClassByQualifiedNameRes
         if (resolverNamespaceData == null) {
             return null;
         }
+        if (resolverNamespaceData == ResolverNamespaceData.NEGATIVE) {
+            throw new IllegalStateException("This means that we are trying to create a Java package, but have a package with the same FQN defined in Kotlin");
+        }
         JavaPackageScope scope = resolverNamespaceData.memberScope;
         if (scope == null) {
             throw new IllegalStateException("fqn: " + fqName);