decompress a tarball with wrong data

[jinzhubaofu]

I got two problem here.

1. decompress a tar.gz file without valid gzip format content, and there should get a NO as return value and an error. But I get YES as return value;

   

   Adding the part of code may fix it.

2. decompres a tar file without valid tar format data, then the app will crash.

   

[daltoniam]

Interesting, I haven't seen that before. I will take a look when time permits.