[PATCH 3/2] qemu-img: Improve error for rebase without backing format

[Kevin Wolf]

Am 08.07.2021 um 17:52 hat Eric Blake geschrieben:
> When removeing support for qemu-img being able to create backing
> chains without embedded backing formats, we caused a poor error
> message as caught by iotest 114.  Improve the situation to inform the
> user what went wrong.
> 
> Suggested-by: Kevin Wolf <kwolf at redhat.com>
> Signed-off-by: Eric Blake <eblake at redhat.com>

Thanks, applied to the block branch.

Kevin