[libvirt] parsing url with percent sign when user want to use iso disk via http

[Michal Privoznik]

On 19.01.2016 13:15, Vasiliy Tolstov wrote:
> I found a strange thing, when i specify url for iso in libvirt xml like:
> 
> qemu gets invalid url in cmdline
> i think that problem is
> qemu/qemu_command.c:3430:            ret = virURIFormat(uri);
> 
> test string looks like  https://alukardd.org/data/test?t=1
> qemu gets url with percent urlencoded %3F , in this case http server
> get not test with param t=1 but filename test%3Ft=1 so this is not
> right.
> 
> why libvirt try to fix contructed url ?
> does it safe to delete this line ?
> 

No it's not safe. Othewise you won't get any source string for your
disk. The line we are talking about is in qemuBuildNetworkDriveURI().
Now, it's virURIFormat that formats the URI and it uses libxml2 for
that. In our tests it seems like we should be discarding escape
sequences in Format(). Take a look at tests/viruritest.c and you'll see.
So maybe a bug in libxml2?

Michal