[libvirt] [PATCH]: fix ruby-libvirt bindings when virConnectNum* returns 0

[Chris Lalancette]

Daniel Veillard wrote:
>   Hum, looking at the bugzilla it's for storage that the problem was raised.
> It's a bit annoying, the main domain and network functions accept a max = 0
> The documentation of virConnectListDefinedStoragePools doesn't prevent
> maxnames = 0
> 
>   Actually the check done in the function is 
>     if ((names == NULL) || (maxnames < 0))
> 
> i.e. it allows 0, and pass it to the underlying driver. One solution
> would be to just return 0 there, as attached in this patch, the other
> solution would be to check which underlying storage driver failed and
> fix it,

Right.  After going through this, I found out that it is actually a NULL check
firing, not a 0 check (see my posted patch for details).  That being said, a
patch of the type posted here might be worthwhile; it would short-circuit the
rest of the calls through the stack, and in particular would avoid on-the-wire
calls in the remote case, to do essentially no work.  I think it would be a nice
optimization for all of the List type operations, but not necessarily required.

Chris Lalancette