--- a/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/OptimisticTypesCalculator.java	Mon Jan 08 11:20:20 2018 +0800
+++ b/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/OptimisticTypesCalculator.java	Mon Jan 08 17:16:37 2018 +0100
@@ -101,13 +101,12 @@
                     tagNeverOptimistic(binaryNode.rhs());
                 }
             }
-        } else if(binaryNode.isTokenType(TokenType.INSTANCEOF)
-                || binaryNode.isTokenType(TokenType.EQ_STRICT)
-                || binaryNode.isTokenType(TokenType.NE_STRICT)) {
+        } else if(binaryNode.isTokenType(TokenType.INSTANCEOF)) {
             tagNeverOptimistic(binaryNode.lhs());
             tagNeverOptimistic(binaryNode.rhs());
         }
-        return true;
+        // Don't enter comparison nodes, see JDK-8193567
+        return !binaryNode.isComparison();
     }
 
     @Override

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/nashorn/script/basic/JDK-8193567.js	Mon Jan 08 17:16:37 2018 +0100
@@ -0,0 +1,36 @@
+/*
+ * 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.
+ * 
+ * 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.
+ */
+
+/**
+ * JDK-8193567: Conversion of comparison nodes affects local slots in optimistic continuation
+ *
+ * @test
+ * @run
+ */
+
+function a() {
+    var x, y;
+    return null == (r = null == (x = this.p) ? void 0 : x.r) ? this : y;
+}
+
+a();