--- a/src/java.base/share/classes/java/text/SimpleDateFormat.java	Thu Jul 12 22:53:35 2018 -0700
+++ b/src/java.base/share/classes/java/text/SimpleDateFormat.java	Fri Jul 13 14:04:59 2018 +0530
@@ -831,7 +831,7 @@
                             break;
                         }
                     }
-                    compiledCode.append((char)(TAG_QUOTE_CHARS << 8 | (j - i)));
+                    encode(TAG_QUOTE_CHARS, j - i, compiledCode);
                     for (; i < j; i++) {
                         compiledCode.append(pattern.charAt(i));
                     }

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/java/text/Format/DateFormat/Bug8193444.java	Fri Jul 13 14:04:59 2018 +0530
@@ -0,0 +1,84 @@
+/*
+ * 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 8193444
+ * @summary Checks SimpleDateFormat.format/parse for the AIOOB exception when
+ *          formatting/parsing dates through a pattern string that contains a
+ *          sequence of 256 or more non-ASCII unicode characters.
+ * @run testng/othervm Bug8193444
+ */
+import org.testng.annotations.DataProvider;
+import org.testng.annotations.Test;
+
+import java.text.DateFormat;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+
+import static org.testng.Assert.assertEquals;
+
+public class Bug8193444 {
+
+    private static final String NON_ASCII_CHAR = "\u263A";
+
+    @DataProvider(name = "dateFormat")
+    Object[][] dateFormatData() {
+        return new Object[][]{
+            // short_length (between 0 and 254)
+            {250},
+            // boundary
+            {254},
+            // long_length
+            {257},};
+    }
+
+    @Test(dataProvider = "dateFormat")
+    public void testDateFormatAndParse(int length)
+            throws ParseException {
+
+        String pattern = NON_ASCII_CHAR.repeat(length);
+
+        DateFormat df = new SimpleDateFormat(pattern);
+        // format() should not throw AIOOB exception
+        String result = df.format(new Date());
+
+        // Since the tested format patterns do not contain any character
+        // representing date/time field, those characters are not interpreted,
+        // they are simply copied into the output string during formatting
+        assertEquals(result, pattern, "Failed to format the date using"
+                + " pattern of length: " + length);
+
+        // The format pattern used by this SimpleDateFormat
+        // contains a sequence of non-ASCII characters, which does not
+        // represent any date/time field. The same sequence is given
+        // for parsing, just to check that the parsing does
+        // not throw any AIOOB exception.
+        // Although as per the parse() specification, the calendar's default
+        // values of the date-time fields are used for any missing
+        // date-time information, but checking that is not the intention of
+        // this test.
+        df.parse(pattern);
+    }
+
+}