[RFR] [8u242] [1/2] 8031111: fix krb5 caddr

[Andrew John Hughes]

Webrev: https://cr.openjdk.java.net/~andrew/openjdk8/8031111/webrev.01/
Bug: https://bugs.openjdk.java.net/browse/JDK-8031111

Recent changes to 8u242 have led to a latent OpenJDK 8 bug being exposed
by the greater use of the KRB_NT_SRV_HST service type. This failure was
exposed by the 8u backport of 8215032 [0]. In
particular, by this line [1]. The reason is that the service Principal
type changed from KRB_NT_UNKNOWN (default in the PrincipalName
constructor that receives a string argument only) to KRB_NT_SRV_HST.

OpenJDK 8u still has this code:

if (server.getNameType() == PrincipalName.KRB_NT_SRV_HST) {
    sAddrs = new HostAddresses(server);
}

which was removed in JDK-8132111 in OpenJDK 9+ [0].

This is the first of two backports to get JDK-8132111 into 8u242. We
will then tag as jdk8u242-b08 & jdk8u242-ga, if there are no further
testing failures.

The main reason to introduce JDK-8031111 as a pre-requisite is that it
also introduces two testcases for this behaviour. Both pass with this
patch. JDK-8132111 will later remove the actual host lookup additions.

It was largely a clean backport. The changes are:

1. Standard addition of -Dsun.net.spi.nameservice.provider.1=ns,mock to
both testcases, a requirement in 8u to be able to look down the rabbit.hole

2. Some contextual differences in KDC.java, due to later changes already
being present in 8u.

[0] https://hg.openjdk.java.net/jdk8u/jdk8u/jdk/rev/6e79bf791069
[1] https://hg.openjdk.java.net/jdk8u/jdk8u/jdk/rev/6e79bf791069#l11.105
[2] https://hg.openjdk.java.net/jdk9/jdk9/jdk/rev/77228d1afabb

This has been internally reviewed by Martin Balao, who has worked on
most of the Kerberos fixes & with whom I diagnosed this issue, so it
just needs a formal review from an 8u reviewer to go in.

I'll flag as jdk8u-critical-request once reviewed.

Thanks,
-- 
Andrew :)

Senior Free Java Software Engineer
Red Hat, Inc. (http://www.redhat.com)

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