Comment 5 for bug 1438738

I thought I'd fix this in neutron today and assigned this to my name before going off to bed. I didn't quite realize that you were also looking into it. The patch above looks pretty good. I just added a couple of more lines of checks with respect to network/subnet negative quotas. I pushed the patch in and marked Salvatore Orlando as the co-author. Please let me know if it's not the right way - I'd be absolutely OK with abandoning my review :)