RFR: 8211917: (zipfs) Creating or updating a JAR file system should put the MANIFEST.MF at the start

[Jaikiran Pai]

Thank you Lance.

-Jaikiran

On 04/02/20 5:12 am, Lance Andersen wrote:
> Hi Jaikiran,
>
> Thank you for tackling this feature request.
>
>
> I will finish going through the proposed patch  and will sponsor once
> we have completed the overall review.
>
>
>
>> On Feb 1, 2020, at 2:38 AM, Jaikiran Pai <jai.forums2013 at gmail.com
>> <mailto:jai.forums2013 at gmail.com>> wrote:
>>
>> Can I please get a review and a sponsor for a patch for
>> https://bugs.openjdk.java.net/browse/JDK-8211917?
>>
>> The webrev containing the patch is available at
>> https://cr.openjdk.java.net/~jpai/webrev/8211917/1/webrev/
>>
>> The commit in the patch updates the jdk.nio.zipfs.ZipFileSystem to write
>> out the manifest (if any) as the first entry in the LOC. That then
>> allows the java.util.jar.JarInputStream to find the manifest and return
>> it through JarInputStream.getManifest().
>>
>> In an initial attempt at this patch, I had tried to just reorder the CEN
>> to add the manifest entry first instead of forcing the manifest entry
>> first in the LOC. But that didn't work and the JarInputStream still
>> couldn't find the manifest. So I used this approach to force the
>> manifest as the first entry in the LOC (and the existing code
>> effectively also ensures that it's also the first entry in the CEN).
>
> Zip/JarInputStream rely on the LOC which is why just updating the CEN
> would not get you across the goal line.
>>
>> The patch also includes a test case to reproduce this issue and verify
>> the change. In the test case I intentionally used the verbose version of
>> the FileSystem.newFileSystem() API, instead of the newer simpler ones.
>> This is to allow cleaner/easier backporting of this patch to Java
>> version 8 if and when that happens. Functionally, which API variant of
>> the FileSystem.newFileSystem() API is used shouldn't matter in the
>> context of this test case. However, if someone feels that I should
>> switch to the newer available API, then please do let me know and I'll
>> update the patch.
>>
>> -Jaikiran
>>
>>
>
> Best
> Lance
>
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> <http://oracle.com/us/design/oracle-email-sig-198324.gif>Lance
> Andersen| Principal Member of Technical Staff | +1.781.442.2037
> Oracle Java Engineering 
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>
>
>
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