--- a/jdk/src/java.base/share/classes/java/util/Formatter.java	Fri Aug 14 14:40:13 2015 +0300
+++ b/jdk/src/java.base/share/classes/java/util/Formatter.java	Sat Aug 15 04:38:51 2015 +0000
@@ -273,6 +273,10 @@
  *
  * </ol>
  *
+ * <p> For category <i>General</i>, <i>Character</i>, <i>Numberic</i>,
+ * <i>Integral</i> and <i>Date/Time</i> conversion, unless otherwise specified,
+ * if the argument <i>arg</i> is {@code null}, then the result is "{@code null}".
+ *
  * <p> The following table summarizes the supported conversions.  Conversions
  * denoted by an upper-case character (i.e. {@code 'B'}, {@code 'H'},
  * {@code 'S'}, {@code 'C'}, {@code 'X'}, {@code 'E'}, {@code 'G'},
@@ -301,14 +305,12 @@
  *
  * <tr><td valign="top"> {@code 'h'}, {@code 'H'}
  *     <td valign="top"> general
- *     <td> If the argument <i>arg</i> is {@code null}, then the result is
- *     "{@code null}".  Otherwise, the result is obtained by invoking
+ *     <td> The result is obtained by invoking
  *     {@code Integer.toHexString(arg.hashCode())}.
  *
  * <tr><td valign="top"> {@code 's'}, {@code 'S'}
  *     <td valign="top"> general
- *     <td> If the argument <i>arg</i> is {@code null}, then the result is
- *     "{@code null}".  If <i>arg</i> implements {@link Formattable}, then
+ *     <td> If <i>arg</i> implements {@link Formattable}, then
  *     {@link Formattable#formatTo arg.formatTo} is invoked. Otherwise, the
  *     result is obtained by invoking {@code arg.toString()}.
  *
@@ -683,6 +685,10 @@
  * methods such as {@link String#format(String,Object...) String.format} and
  * {@link java.io.PrintStream#printf(String,Object...) PrintStream.printf}.
  *
+ * <p> For category <i>General</i>, <i>Character</i>, <i>Numberic</i>,
+ * <i>Integral</i> and <i>Date/Time</i> conversion, unless otherwise specified,
+ * if the argument <i>arg</i> is {@code null}, then the result is "{@code null}".
+ *
  * <p> Conversions denoted by an upper-case character (i.e. {@code 'B'},
  * {@code 'H'}, {@code 'S'}, {@code 'C'}, {@code 'X'}, {@code 'E'},
  * {@code 'G'}, {@code 'A'}, and {@code 'T'}) are the same as those for the
@@ -722,9 +728,8 @@
  *     <td valign="top"> <code>'&#92;u0068'</code>
  *     <td> Produces a string representing the hash code value of the object.
  *
- *     <p> If the argument, <i>arg</i> is {@code null}, then the
- *     result is "{@code null}".  Otherwise, the result is obtained
- *     by invoking {@code Integer.toHexString(arg.hashCode())}.
+ *     <p> The result is obtained by invoking
+ *     {@code Integer.toHexString(arg.hashCode())}.
  *
  *     <p> If the {@code '#'} flag is given, then a {@link
  *     FormatFlagsConversionMismatchException} will be thrown.
@@ -737,8 +742,7 @@
  *     <td valign="top"> <code>'&#92;u0073'</code>
  *     <td> Produces a string.
  *
- *     <p> If the argument is {@code null}, then the result is
- *     "{@code null}".  If the argument implements {@link Formattable}, then
+ *     <p> If the argument implements {@link Formattable}, then
  *     its {@link Formattable#formatTo formatTo} method is invoked.
  *     Otherwise, the result is obtained by invoking the argument's
  *     {@code toString()} method.

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/util/Formatter/NullArg.java	Sat Aug 15 04:38:51 2015 +0000
@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2015, 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 8039390
+ * @summary Basic test for null argument
+ */
+
+import java.util.Formatter;
+import java.util.Locale;
+
+public class NullArg {
+
+    public static void main(String [] args) {
+        char[] cs = new char[] {
+            'b', 'B', 'h', 'H', 's', 'S', 'c', 'C', 'd', 'o', 'x', 'X',
+            'e', 'E', 'f', 'g', 'G', 'a', 'A', 't', 'T',
+        };
+        char[] tcs = new char[] {
+            'H', 'I', 'k', 'l', 'l', 'M', 'S', 'L', 'N', 'p', 'z', 'Z', 's',
+            'Q', 'B', 'b', 'h', 'A', 'a', 'C', 'Y', 'y', 'j', 'm', 'd', 'e',
+            'R', 'T', 'r', 'D', 'F', 'c'
+        };
+        for (char c : cs) {
+            String expected = (c == 'b' || c == 'B') ? "false" : "null";
+            if (Character.isUpperCase(c)) {
+                expected = expected.toUpperCase(Locale.ROOT);
+            }
+            if (c == 't' || c == 'T') {
+                for (char ct : tcs) {
+                    if (!String.format("%" + c + ct, null).equals(expected)) {
+                        throw new RuntimeException("%t" + ct + "null check failed.");
+                    }
+                }
+            } else {
+                if (!String.format("%" + c , null).equals(expected)) {
+                    throw new RuntimeException("%" + c + "null check failed.");
+                }
+            }
+        }
+    }
+}