Comment 1 for bug 981319

Looking at the code, here's what appears to happen:

1) image metadata is updated with what the user provides
2) image status set to saving
3) image data streamed to store
4) image status set to active

This failure occurs when the image is being set to active since that's when we require a valid combination of disk_format and container_format. At this point, your image data has been uploaded to the store and you should be able to do another PUT with a valid disk_format/container_format and status='active'. I agree this isn't ideal, but its better than activating an image before we have any actual data.