RFR: 8176709: JarFileSystem::isMultiReleaseJar is incorrect

[Claes Redestad]

Hi,

Alan raised some concerns offline that we should try to reduce the
number of qualified exports, not adding more, and that it might be
better to accept some code duplication here. Thus I'm proposing this as
an alternative:

http://cr.openjdk.java.net/~redestad/8176709/jdk.02/

Neither solution is exactly pretty, but this approach removes any
performance risk of jdk.01 and by at least calling out that there's
some duplication around should avoid us slipping back into a similar
situation again.

Thanks!

/Claes

On 2017-03-14 16:04, Claes Redestad wrote:
> Hi,
>
> please review this change to adapt the JarFileSystem::isMultiReleaseJar
> method to align with the evolved specification in JEP 238
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8176709
> Webrev: http://cr.openjdk.java.net/~redestad/8176709/jdk.01/
>
> This unfortunately adds a qualified export from java.base to jdk.zipfs,
> but since the jdk.internal.util.jar package was already exported to
> three other modules I think it's a low cost option that is preferable
> to other alternatives such as maintaining separate implementations.
>
> Thanks!
>
> /Claes