InternetAddress.getLocalAddress should use InetAddress.getCanonicalHostName -

bug 7471

Author: bshannon

doc/release/CHANGES.txt

@@ -29,6 +29,8 @@ K  7238	unsolicited FETCH response *must* invalidate X-GM-LABELS in cache
 K  7332	MimeBodyPart.isMimeType returns false if type header can't be parsed
 K  7356	NPE in Tomcat ClassLoader causes Session.getInstance to fail
 K  7378	Deadlock in IMAPFolder.doProtocolCommand()
+K  7471	InternetAddress.getLocalAddress should use
+	InetAddress.getCanonicalHostName
 
 
 		  CHANGES IN THE 1.5.5 RELEASE

doc/release/COMPAT.txt

@@ -14,6 +14,18 @@ implementation.  This note summarizes potential compatibility issues
 with this release of the JavaMail API.
 
 
+-- JavaMail 1.5.6 --
+
+- InternetAddress.getLocalAddress uses canonical host name
+
+	The InternetAddress.getLocalAddress method now uses the
+	java.net.InetAddress.getCanonicalHostName method if neither the
+	"mail.from" nor "mail.host" properties have been set.  The System
+	property "mail.mime.address.usecanonicalhostname" can be set to
+	"false" to revert to the previous behavior.
+
+
+
 -- JavaMail 1.5.4 --
 
 - Idlemanager.watch no longer throws IOException

mail/src/main/java/javax/mail/internet/InternetAddress.java

@@ -85,6 +85,10 @@ public class InternetAddress extends Address implements Cloneable {
 	PropUtil.getBooleanSystemProperty(
 			    "mail.mime.address.ignorebogusgroupname", true);
 
+    private static final boolean useCanonicalHostName =
+	PropUtil.getBooleanSystemProperty(
+			    "mail.mime.address.usecanonicalhostname", true);
+
     /**
      * Default constructor.
      */
@@ -567,7 +571,14 @@ private static String getLocalHostName() throws UnknownHostException {
 	String host = null;
 	InetAddress me = InetAddress.getLocalHost();
 	if (me != null) {
-	    host = me.getHostName();
+	    // try canonical host name first
+	    if (useCanonicalHostName)
+		host = me.getCanonicalHostName();
+	    if (host == null)
+		host = me.getHostName();
+	    // if we can't get our name, use local address literal
+	    if (host == null)
+		host = me.getHostAddress();
 	    if (host != null && host.length() > 0 && isInetAddressLiteral(host))
 		host = '[' + host + ']';
 	}

mail/src/main/java/javax/mail/internet/package.html

@@ -5,7 +5,7 @@
 
     DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 
-    Copyright (c) 1997-2015 Oracle and/or its affiliates. All rights reserved.
+    Copyright (c) 1997-2016 Oracle and/or its affiliates. All rights reserved.
 
     The contents of this file are subject to the terms of either the GNU
     General Public License Version 2 only ("GPL") or the Common Development
@@ -542,6 +542,25 @@ <H4>Properties</H4>
 </TD>
 </TR>
 
+<A NAME="mail.mime.address.usecanonicalhostname"></A>
+<TR id="mail.mime.address.usecanonicalhostname">
+<TD>mail.mime.address.usecanonicalhostname</TD>
+<TD>boolean</TD>
+<TD>
+Use the
+{@link java.net.InetAddress#getCanonicalHostName InetAddress.getCanonicalHostName}
+method to determine the host name in the
+{@link javax.mail.internet.InternetAddress#getLocalAddress InternetAddress.getLocalAddress}
+method.
+With some network configurations, InetAddress.getCanonicalHostName may be
+slow or may return an address instead of a host name.
+In that case, setting this System property to false will cause the
+{@link java.net.InetAddress#getHostName InetAddress.getHostName}
+method to be used instead.
+The default is true.
+</TD>
+</TR>
+
 </TABLE>
 <P>
 The current