[jira] [Updated] (COMPRESS-474) xlsx zip64 compatibility

["Stefan Bodewig (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/COMPRESS-474?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Stefan Bodewig updated COMPRESS-474:
------------------------------------
    Labels: zip  (was: )

> xlsx zip64 compatibility
> ------------------------
>
>                 Key: COMPRESS-474
>                 URL: https://issues.apache.org/jira/browse/COMPRESS-474
>             Project: Commons Compress
>          Issue Type: Bug
>          Components: Archivers
>    Affects Versions: 1.19
>            Reporter: Krzysztof Rzymkowski
>            Priority: Major
>              Labels: zip
>
> Excel's xlsx files are generally zip archives. But Excel has a very specific and strict ZIP64 implementation.
> Connected Apache POI issue: [https://bz.apache.org/bugzilla/show_bug.cgi?id=57342
>  ]My blog post with all the details: [https://rzymek.github.io/post/excel-zip64/]
> My observations on Excel requirements:
>  # If file size is > 4gb, then zip spec version 4.5 must be set in Local Header File
>  # In streaming creation the zero file sizes must be in 32 field, not in LHF's ZIP64 extra field data.
>  # ZIP64 extra field in Central Directory must not include relativeHeaderOffset. Only size or size and compressed size
>  # ZIP64 Central Directory is not supported
> I did verify these in a +prototype+ repository at [https://github.com/rzymek/commons-compress/pull/1/files]. This is just a playground where I've tested the changes to verify that Excel opens the generated file.
> Test project: https://github.com/rzymek/xlsx-compress64-test
>  
>  



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