FULL PRODUCT VERSION :
java version "1.8.0_45"
Java(TM) SE Runtime Environment (build 1.8.0_45-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.45-b02, mixed mode)


ADDITIONAL OS VERSION INFORMATION :
Linux mybox 2.6.32-220.13.1.el6.centos.plus.x86_64 #1 SMP Wed Apr 18 02:32:59 BST 2012 x86_64 x86_64 x86_64 GNU/Linux

EXTRA RELEVANT SYSTEM CONFIGURATION :
$ hostname

mybox

$ hostname -i

185.69.214.74

$ host $(185.69.214.74)

74.214.69.185.in-addr.arpa domain name pointer 185-69-214-74.ded.intelignet.com.br.

A DESCRIPTION OF THE PROBLEM :
If I omit "-Djava.net.preferIPv4Stack=true", InetAddress.getLocalHost calls Inet6AddressImpl.getLocalHostName (in line 1453), which returns "mybox" and everything works just fine.

However, if I do use "-Djava.net.preferIPv4Stack=true", InetAddress.getLocalHost calls Inet4AddressImpl.getLocalHostName which returns "185-69-214-74.ded.intelignet.com.br".

REGRESSION. Last worked in version 7u75

ADDITIONAL REGRESSION INFORMATION:
java version "1.7.0_45"
Java(TM) SE Runtime Environment (build 1.7.0_45-b18)
Java HotSpot(TM) 64-Bit Server VM (build 24.45-b08, mixed mode)


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Compile and run the provided test case using the option -Djava.net.preferIPv4Stack=true

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
mybox/185.69.214.74
ACTUAL -
java.net.UnknownHostException: 185-69-214-74.ded.intelignet.com.br: 185-69-214-74.ded.intelignet.com.br: unknown error
        at java.net.InetAddress.getLocalHost(InetAddress.java:1484)
        at GetLocalHost.main(GetLocalHost.java:9)

Caused by: java.net.UnknownHostException: 185-69-214-74.ded.intelignet.com.br: unknown error
        at java.net.Inet4AddressImpl.lookupAllHostAddr(Native Method)
        at java.net.InetAddress$2.lookupAllHostAddr(InetAddress.java:907)
        at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1302)
        at java.net.InetAddress.getLocalHost(InetAddress.java:1479)
        ... 1 more


ERROR MESSAGES/STACK TRACES THAT OCCUR :
java.net.UnknownHostException: 185-69-214-74.ded.intelignet.com.br: 185-69-214-74.ded.intelignet.com.br: unknown error
        at java.net.InetAddress.getLocalHost(InetAddress.java:1484)
        at GetLocalHost.main(GetLocalHost.java:9)

Caused by: java.net.UnknownHostException: 185-69-214-74.ded.intelignet.com.br: unknown error
        at java.net.Inet4AddressImpl.lookupAllHostAddr(Native Method)
        at java.net.InetAddress$2.lookupAllHostAddr(InetAddress.java:907)
        at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1302)
        at java.net.InetAddress.getLocalHost(InetAddress.java:1479)
        ... 1 more


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.net.InetAddress;
import java.net.UnknownHostException;

public class GetLocalHost {

    public static void main( final String[] args ) {

        try {
            System.out.println( InetAddress.getLocalHost() );

        } catch ( final UnknownHostException e ) {
            e.printStackTrace();
        }
    }

}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
edit /etc/hosts to add this line:

185.69.214.74 185-69-214-74.ded.intelignet.com.br