Creating a zip with a directory inside and then previewing in iOS crashes Quick Look

1 min read Original article ↗

Hi there,

Zip files created by ZipZap with directories inside seem to crash on iOS when previewed by Quick Look. See this project for an example (build & run the ZipZapDirectoryTest target). The following is logged to the console:

2016-02-19 01:33:40.343 ZipZapDirectoryTest[729:187096] BOM could not extract archive: Couldn't read pkzip signature.
2016-02-19 01:33:40.344 ZipZapDirectoryTest[729:187096] BOM could not extract archive: Not a central directory signature

A few interesting/strange points of note:

  • Creating a zip with the same contents from Finder in OS X does not exhibit the same issue when the file is previewed on iOS (an example is provided in the aforementioned demo app)
  • If you take the zip file created with ZipZap and extract it under Finder in OS X, it works fine.
  • Strangely, if you skip adding the archive entry provided by -archiveEntryWithDirectoryName:, iOS is able to successfully preview the zip. But, I'm worried that other apps might consider this to be a malformed zip.

Hoping for some guidance here as to why iOS is considering ZipZap's archives to be malformed.

Thanks!
Ari