RFR(xs): 6991580: IPv6 Nameservers in resolv.conf throws NumberFormatException

[Severin Gehwolf]

Hi,

Could I please get a review and a sponsor for the following patch?

The issue is that JDK's internal /etc/resolv.conf nameserver parsing
does not properly account for IPv6 addresses on Linux/Unix. While the
code in com.sun.jndi.dns.DnsClient seems to support IPv6 addresses
passed in via the servers list in the constructor it expects IPv6
addresses to be wrapped in '[' and ']' respectively. However,
sun.net.dns.ResolverConfigurationImpl does no wrapping of IPv6 addresses
when parsing "nameserver" keywords from /etc/resolv.conf, thus breaking
DnsClient's contract.

The fix is to properly wrap IPv6 literal addresses in '[' and ']' if not
already wrapped.

Bug: https://bugs.openjdk.java.net/browse/JDK-6991580
Webrev:
http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-6991580/webrev.01/

Testing done: Added regression test fails for unpatched 9 and passes for
patched 9.

Thanks,
Severin