icsharpcode/SharpZipLib

ZipFile.Create(archivePath) creates 0 bytes archive.

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#395 opened on Nov 14, 2019

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 (2 comments) (2 reactions) (0 assignees)C# (3,502 stars) (964 forks)batch import
enhancementhelp wantedzip

Description

Steps to reproduce

  1. Use ZipFile.Create(archivePath) to create an archive.
  2. Close created ZipFile without adding anything to it.

Expected behavior

Created archive have non-zero size (should have "End of central directory record" and be at least 22 bytes according to specification)

Actual behavior

Archive size is 0 bytes, attempt to open it with new ZipFile(archivePath) leads to ZipException "Cannot find central directory"

Version of SharpZipLib

1.1.0 also tried 1.2.0

Obtained from (only keep the relevant lines)

  • Package installed using NuGet

Contributor guide

Tech stack
csharp
Domain
backend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
under 1 hour
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
C#ZIP file format knowledge
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70
Research direction
Investigate the ZipFile implementation in SharpZipLib, particularly the Create and Dispose methods. Ensure that when a ZipFile is created and closed without adding any entries, it writes the End of Central Directory record per the ZIP specification. Check the file ZipFile.cs and related tests to understand the current behavior and add a fix to write the EOCD in such cases.