7z inflation fails.

[TomerHeber]

Hi,

I'm using the latest libarchive release (not master).

I've created a file with 7zip (lzma - default settings).
I then tried to inflate it VIA libarchive.

I was unable to get it to work. It would fail without an error reason.

So I started debugging the code and discovered that I'm missing the "seek_callback" (Too bad there is no error code for that).

After implementing the "seek_callback" I tried again. It had failed again but this time it told me the 7zip header is corrupted.

So I started debugging a second time and discovered there is a bug in the libarchive 7zip code. It would seem that libarchive 7zip has issues with handling the "Dummy" header (kDummy). The "Dummy" header is for padding and is often of length 0. The current code has issues with handling headers of length 0.

After fixing the bug - inflation was successful.

To reproduce:

1. Create a 7z archive VIA 7zip.
2. Try inflating it with libarchive (don't forget to add a seek_callback).

10x,
Tomer.

[kientzle]

Thank you for the report.

The best way to get such issues fixed is to provide us with a small sample file (ideally, just a few kilobytes) that demonstrates the problem. We can then add that to our test suite, which will both help us quickly fix the problem and ensure it does not reappear in the future.

Of course, if you also have a fix for the bug, we always appreciate pull requests.

[Marshallx]

I think I have the same problem - any 7z file created in the latest 7zip beta.
7-zip itself can reopen/extract these archives ok.

[TomerHeber]

Hopefully I'll find the time to submit the bug fix asap.

On Tue, Jun 16, 2015, 17:35 Marshallx notifications@github.com wrote:

I think I have the same problem - any 7z file created in the latest 7zip
beta.
7-zip itself can reopen/extract these archives ok.

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#556 (comment)
.

[TomerHeber]

Pull request created.
#560

[kientzle]

Thanks for the bug fix!

[Marshallx]

Hey, was this related to open issue
#535
?

[TomerHeber]

Commented in #535 .