Failure while executing KTar::open while using KCompressionDevice as the device

[Luiz Romário Santana Rios]

Hello,

I'm trying to decompress a XZ archive downloaded using
QNetworkAccessManager, so, according to the documents, I have to pass
the QNetworkReply pointer to a KCompressionDevice and, then, use it as
Ktar's device like this:

https://gist.github.com/anonymous/b8fb686367f518a7dbb5

The problem is that KTar::open() fails and returns false. The file I'm
trying to extract has the following structure more or less:
/root
/root/dir
/root/dir/file1
/root/dir/file2
...

So, as far as I've seen, the code runs normally when entering /root
and /root/dir, but, pretty high in the stack, at
KXzFilter::uncompress(), the call to lzma_code returns
LZMA_FORMAT_ERROR while trying to uncompress file1 (or file2, I'm not
sure). Here's the call stack:

https://gist.github.com/anonymous/9ea380cfe48daadb5971

Is this a bug? If it's a bug, how can I proceed to fix it?

Thanks for the attention.

-- 
Luiz Romário Santana Rios