Range encodes an integer interval [a,b] as { begin = a, end = b + 1 },
where a \in [0,2^64-1] and b \in [1,2^64]. Thus, zero end is to be
interpreted as 2^64.
The implementation of -dfilter (commit 3514552) uses Range
differently: it encodes [a,b] as { begin = a, end = b }. The code
works, but it contradicts the specification of Range in range.h.
Switch to the specified representation. Since it can't represent
[0,UINT64_MAX], we have to reject that now. Add a test for it.
While we're rejecting anyway: observe that we reject -dfilter LOB..UPB
where LOB > UPB when UPB is zero, but happily create an empty Range
when it isn't. Reject it then, too, and add a test for it.
While there, add a positive test for the problematic upper bound
UINT64_MAX.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
58e19e6e79