RFR: 8345431: Detect duplicate entries in jar files with jar --validate

[Lance Andersen]

On Fri, 4 Apr 2025 16:12:56 GMT, Lance Andersen <lancea at openjdk.org> wrote:

>> As we checking entry uniqueness and  the size match, and all LOC entries should be in CEN, that would means all CEN entries in LOC.
>> But if we would like to be specific about the inconsistency, then we will have to do a little more work.
>
> Yes, in a perfect world there will be a 1 to 1 match but either way we should sanity check it in case something happened

> Is the ordering required by ZIP or Jar format? We can certainly do that if that's under spec and not an implementation detail.

The Zip Spec states the following:


> 4.3.2 Each file placed into a ZIP file MUST be preceded by  a "local 
>    file header" record for that file.  Each "local file header" MUST be 
>    accompanied by a corresponding "central directory header" record within 
>    the central directory section of the ZIP file.

That being said I am not aware of any implementations  where the order is different given you have to generate the LOC prior to the CEN and End of CEN

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/24430#discussion_r2029133374