ZIP file created with SharpZipLib cannot be opened on Mac OS X

Question

Argh, today is the day of stupid problems and me being an idiot.

I have an application which creates a zip file containing some JPEGs from a certain directory. I use th

Answer 1

There are two things:

• Ensure your underlying output stream is seekable, or SharpZipLib won't be able to back up and fill in any ZipEntry fields that you omitted (size, crc, compressed size, ...). As a result, SharpZipLib will force "bit 3" to be enabled. The background has been explained pretty well in previous answers.

• Fill in ZipEntry.Size, or explicitly set stream.UseZip64 = UseZip64.Off. The default is to conservatively assume the stream could be very large. Unzipping then requires "pk 4.5" support.