[libvirt] [PATCH] qemu: Allow empty script path to <interface/>

[Michal Privoznik]

On 02/02/2017 02:56 PM, Daniel P. Berrange wrote:
> On Thu, Feb 02, 2017 at 02:49:48PM +0100, Michal Privoznik wrote:
>> Before 9c17d665fdc5f (v1.3.2 - I know, right?) it was possible to
>> have the following interface configuration:
>>
>>   <interface type='ethernet'/>
>>     <script path=''/>
>>   </interface>
>>
>> This resulted in -netdev tap,script=,.. Fortunately, qemu helped
>> us to get away with this as it just ignored the empty script
>> path. However, after the commit mentioned above it's libvirtd
>> who is executing the script. Unfortunately without special
>> case-ing empty script path.
>>
>> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
> 
> This was always invalid input and the fact that it happened
> to work in the past is just luck. Since this has been broken since
> 1.3.2 there's plenty of libvirt releases that reject this, and so
> any app realistically has to be fixed to omit the <script> entirely
> if they want any portability. As such I don't think we need to "fix"
> this.

Fair enough. Although, 1.3.2 was not that long time ago (~a year). BTW:
it's openstack who is still using this.

https://bugzilla.redhat.com/show_bug.cgi?id=1412834

Michal