--- old/src/java.base/share/classes/java/io/DataOutputStream.java	2019-03-15 12:22:37.000000000 -0700
+++ new/src/java.base/share/classes/java/io/DataOutputStream.java	2019-03-15 12:22:37.000000000 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1994, 2004, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1994, 2019, 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
@@ -345,12 +345,16 @@
      */
     static int writeUTF(String str, DataOutput out) throws IOException {
         int strlen = str.length();
-        int utflen = 0;
-        int c, count = 0;
 
-        /* use charAt instead of copying String to char array */
+        // UTF length >= strlen so fail-fast if strlen is too long
+        if (strlen > 65535)
+            throw new UTFDataFormatException(
+                "encoded string would be too long: > 65535 bytes");
+
+        // use charAt instead of copying String to char array
+        int utflen = 0;
         for (int i = 0; i < strlen; i++) {
-            c = str.charAt(i);
+            int c = str.charAt(i);
             if ((c >= 0x0001) && (c <= 0x007F)) {
                 utflen++;
             } else if (c > 0x07FF) {
@@ -374,18 +378,19 @@
             bytearr = new byte[utflen+2];
         }
 
+        int count = 0;
         bytearr[count++] = (byte) ((utflen >>> 8) & 0xFF);
         bytearr[count++] = (byte) ((utflen >>> 0) & 0xFF);
 
         int i=0;
         for (i=0; i<strlen; i++) {
-           c = str.charAt(i);
+           int c = str.charAt(i);
            if (!((c >= 0x0001) && (c <= 0x007F))) break;
            bytearr[count++] = (byte) c;
         }
 
         for (;i < strlen; i++){
-            c = str.charAt(i);
+            int c = str.charAt(i);
             if ((c >= 0x0001) && (c <= 0x007F)) {
                 bytearr[count++] = (byte) c;
 
--- old/test/jdk/java/io/DataOutputStream/WriteUTF.java	2019-03-15 12:22:37.000000000 -0700
+++ new/test/jdk/java/io/DataOutputStream/WriteUTF.java	2019-03-15 12:22:37.000000000 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2019, 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
@@ -22,14 +22,21 @@
  */
 
 /* @test
-   @bug 4260284
-   @summary Test if DataOutputStream will overcount written field.
-*/
+ * @bug 4260284 8219196
+ * @summary Test if DataOutputStream will overcount written field.
+ * @run testng WriteUTF
+ */
+
+import java.io.ByteArrayOutputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.io.UTFDataFormatException;
 
-import java.io.*;
+import org.testng.annotations.Test;
 
 public class WriteUTF {
-    public static void main(String[] args) throws Exception {
+    @Test
+    public static void overcountWrittenField() throws IOException {
         ByteArrayOutputStream baos = new ByteArrayOutputStream();
         DataOutputStream dos = new DataOutputStream(baos);
         dos.writeUTF("Hello, World!");  // 15
@@ -37,4 +44,32 @@
         if  (baos.size() != dos.size())
             throw new RuntimeException("Miscounted bytes in DataOutputStream.");
     }
+
+    private static void writeUTF(int size) throws IOException {
+        StringBuilder sb = new StringBuilder(size);
+        // this character gives 3 bytes when encoded using UTF-8
+        char c = 0x0800;
+        for (int i = 0; i < size; ++i) {
+            sb.append(c);
+        }
+        ByteArrayOutputStream bos = new ByteArrayOutputStream();
+        DataOutputStream dos = new DataOutputStream(bos);
+        String s = sb.toString();
+        // throws ArrayIndexOutOfBoundsException instead of expected
+        // UTFDataFormatException
+        dos.writeUTF(s);
+    }
+
+    @Test(expectedExceptions = UTFDataFormatException.class)
+    public void utfDataFormatException() throws IOException {
+        writeUTF(1 << 16);
+    }
+
+    // Without 8219196 fix, throws ArrayIndexOutOfBoundsException instead of
+    // expected UTFDataFormatException. Disabled because it requires 4GB of
+    // heap (-Xmx4g) to run without throwing an OutOfMemoryError.
+    @Test(expectedExceptions = UTFDataFormatException.class, enabled = false)
+    public void arrayIndexOutOfBoundsException() throws IOException {
+        writeUTF(Integer.MAX_VALUE / 3 + 1);
+    }
 }