RFR: 8153213: Jar manifest attribute "Multi-Release" accepts any value

[Steve Drach]

Hi,

I’ve updated the following patch, incorporating code by Claes Redestad to handle some corner cases while processing the attribute value.  Note that we’ve limited the location of the value part of the attribute to accommodate startup performance requirements.  It’s not without precedent as at least one other attribute is also limited in amount of whitespace surrounding the value.

> Please review this simple fix to require that the jar manifest Multi-Release attribute has a value of “true" in order to be effective, i.e. to assert the jar is a multi-release jar.

issue: https://bugs.openjdk.java.net/browse/JDK-8153213 <https://bugs.openjdk.java.net/browse/JDK-8153213>
webrev: http://cr.openjdk.java.net/~sdrach/8153213/webrev.01/index.html <http://cr.openjdk.java.net/~sdrach/8153213/webrev.01/index.html>


Thanks
Steve