J2SE Version (please include all output from java -version flag):
java version "1.7.0_09"
Java(TM) SE Runtime Environment (build 1.7.0_09-b05)
Java HotSpot(TM) 64-Bit Server VM (build 23.5-b02, mixed mode)


Does this problem occur on J2SE 6ux or 7ux?  Yes / No (pick one)
6: probably
7u9: yes
7u12: yes


Operating System Configuration Information (be specific):
Darwin macbook-retina.speedport.ip 12.2.1 Darwin Kernel Version 12.2.1: Thu Oct 18 16:32:48 PDT 2012; root:xnu-2050.20.9~2/RELEASE_X86_64 x86_64


Hardware Configuration Information (be specific):
Macbook Pro Retina 15"


Bug Description:

scope_ifname_set field not set correctly.

The problem occurs in two scenarios:
1. When iterating over all InetAddresses returned by NetworkInterface class on OS X (not tested on Win nor Linux)
2. When deserializing Inet6Address (bug in readObject() method)

java.net.Inet6Address#readObject() does not set field scope_ifname_set on deserialization even if network interface name could be verified.

Even though the field ifname is set, the field scope_ifname_set is not set to true, which prevents the interface name to be returned in getHostAddr().

This is even true for all Inet6Addresses returned by java.net.NetworkInterface#getNetworkInterfaces on OS-X. Means: all Inet6Addresses have the field scope_ifname_set==false but the field ifname contains the correct interface name.
Seems that the following line should be added before the current line #429 in java/net/Inet6Address.java :
	scope_ifname_set = true;
so that the try-catch looks like:
                    try {
                        scope_id = deriveNumericScope (scope_ifname);
                        scope_ifname_set = true;
                    } catch (UnknownHostException e) {
                        // typically should not happen, but it may be that
                        // the machine being used for deserialization has
                        // the same interface name but without IPv6 configured.
                    }



Steps to Reproduce (be specific):



import java.net.Inet6Address;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.util.Enumeration;

public class Jdk7NoIfname {

    public static void main(String args[]) throws SocketException {
        for (Enumeration<NetworkInterface> e = NetworkInterface.getNetworkInterfaces(); e.hasMoreElements(); ) {
            NetworkInterface iface = e.nextElement();
            for (Enumeration<InetAddress> iadrs = iface.getInetAddresses(); iadrs.hasMoreElements(); ) {
                InetAddress iadr = iadrs.nextElement();
                if (iadr instanceof Inet6Address) {
                    Inet6Address i6adr = (Inet6Address) iadr;
                    System.out.println(iadr);
                    System.out.println("  scoped iface: "+i6adr.getScopedInterface());
                }
            }
        }
    }
}



The output produces 
/fe80:0:0:0:426c:8fff:fe3a:ba79%6
  scoped iface: name:en2 (en2)
/0:0:0:0:0:0:0:1
  scoped iface: null
/fe80:0:0:0:0:0:0:1%1
  scoped iface: name:lo0 (lo0)

But the output should look like this
/fe80:0:0:0:426c:8fff:fe3a:ba79%en2
  scoped iface: name:en2 (en2)
/0:0:0:0:0:0:0:1
  scoped iface: null
/fe80:0:0:0:0:0:0:1%lo0
  scoped iface: name:lo0 (lo0)