--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/langtools/tools/javac/switchexpr/ExpressionSwitchBugsInGen.java	Mon Dec 03 10:37:36 2018 +0100
@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2018, 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.
+ *
+ * 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 8214031
+ * @summary Verify various corner cases with nested switch expressions.
+ * @compile --enable-preview -source 12 ExpressionSwitchBugsInGen.java
+ * @run main/othervm --enable-preview ExpressionSwitchBugsInGen
+ */
+
+public class ExpressionSwitchBugsInGen {
+    public static void main(String... args) {
+        new ExpressionSwitchBugsInGen().test(0, 0, 0, false);
+        new ExpressionSwitchBugsInGen().test(0, 0, 1, true);
+        new ExpressionSwitchBugsInGen().test(0, 1, 1, false);
+        new ExpressionSwitchBugsInGen().test(1, 1, -1, true);
+        new ExpressionSwitchBugsInGen().test(1, 12, -1, false);
+        new ExpressionSwitchBugsInGen().testCommonSuperType(0, "a", new StringBuilder(), "a");
+        new ExpressionSwitchBugsInGen().testCommonSuperType(1, "", new StringBuilder("a"), "a");
+        new ExpressionSwitchBugsInGen().testSwitchExpressionInConditional(0, null, -1);
+        new ExpressionSwitchBugsInGen().testSwitchExpressionInConditional(1, "", 0);
+        new ExpressionSwitchBugsInGen().testSwitchExpressionInConditional(1, 1, 1);
+        new ExpressionSwitchBugsInGen().testIntBoxing(0, 10, 10);
+        new ExpressionSwitchBugsInGen().testIntBoxing(1, 10, -1);
+    }
+
+    private void test(int a, int b, int c, boolean expected) {
+        if ( !(switch (a) {
+                case 0 -> b == (switch (c) { case 0 -> 0; default -> 1; });
+                default -> b == 12;
+            })) {
+            if (!expected) {
+                throw new IllegalStateException();
+            }
+        } else {
+            if (expected) {
+                throw new IllegalStateException();
+            }
+        }
+    }
+
+    private void testCommonSuperType(int a, String s1, StringBuilder s2, String expected) {
+        String r = (switch (a) {
+            case 0 -> s1;
+            default -> s2;
+        }).toString();
+        if (!expected.equals(r)) {
+            throw new IllegalStateException();
+        }
+    }
+
+    private void testSwitchExpressionInConditional(int a, Object o, int expected) {
+        int v = a == 0 ? -1
+                       : switch (o instanceof String ? 0 : 1) {
+                             case 0 -> 0;
+                             default -> 1;
+                       };
+        if (v != expected) {
+            throw new IllegalStateException();
+        }
+    }
+
+    private void testIntBoxing(int a, Integer res, int expected) {
+        int r = switch (a) {
+            case 0 -> res;
+            default -> -1;
+        };
+        if (r != expected) {
+            throw new IllegalStateException();
+        }
+    }
+
+}