Skip to content

Write ZIP64 End of Central Directory only if needed. - #601

Merged
adamhathcock merged 2 commits into
adamhathcock:masterfrom
salvois:master
Jun 4, 2021
Merged

Write ZIP64 End of Central Directory only if needed.#601
adamhathcock merged 2 commits into
adamhathcock:masterfrom
salvois:master

Conversation

@salvois

@salvois salvois commented May 23, 2021

Copy link
Copy Markdown

Both Excel and LibreOffice fail to open an XLSX file compressed with SharpCompress when using ZIP64 (Excel is able to repair it, LibreOffice refuses it altogether).

Avoiding the ZIP64 End of Central Directory record when values are representable by the non-ZIP64 End of Central Directory record solves the issue.

This seems to be supported by the ZIP file format specification: "If one of the fields in the end of central directory record is too small to hold required data, the field SHOULD be set to -1 (0xFFFF or 0xFFFFFFFF) and the ZIP64 format record SHOULD be created." (https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT version 6.3.9, paragraph 4.4.1.4).

@adamhathcock

Copy link
Copy Markdown
Owner

Seems correct. Thanks.

@adamhathcock
adamhathcock merged commit 161f99b into adamhathcock:master Jun 4, 2021
@adamhathcock

Copy link
Copy Markdown
Owner

Released https://www.nuget.org/packages/SharpCompress/0.28.3

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

2 participants