--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/langtools/tools/javac/generics/inference/8178427/T8178427.java	Tue Nov 28 18:51:55 2017 +0000
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8178427
+ * @summary NPE in Infer$CheckUpperBounds
+ * @compile T8178427.java
+ */
+
+import java.util.Map;
+import java.util.concurrent.ExecutorService;
+import java.util.function.*;
+import java.util.stream.*;
+
+abstract class X {
+    public interface N<K, V> {
+        Stream<V> getValues();
+    }
+
+    abstract <K, V> N<K, V> c();
+
+    abstract <T, K, V, M extends N<K, V>> Collector<T, ?, M> f(
+            Function<? super T, ? extends K> k,
+            Function<? super T, ? extends Stream<? extends V>> v,
+            Supplier<M> multimapSupplier);
+
+    void m(Map<String, N<?, ?>> c, ExecutorService s) {
+        s.submit(() -> {
+            return c.entrySet().parallelStream()
+                    .collect(f(Map.Entry::getKey, e -> e.getValue().getValues(), this::c));
+        });
+    }
+}
+