Data::ObjectDriver::Driver::BaseCache::lookup_multi optimistic assumption

[sewi-cpan]

Data::ObjectDriver::Driver::BaseCache::lookup_multi does this after fetching items from memcached:
if (scalar keys %$got == @$ids) {
The idea looks good: If memcached get_multi returned the same number of items as requested, all must be within the result, but that's wrong!
We're currently experiencing a Cache::Memcached bug sometimes destroying a key name if the response is being read in two system calls. The key returned from get_multi is not the one requested (which is the same actually returned from memcached). That's another bug which must be fixed, but Data::ObjectDriver::Driver::BaseCache::lookup_multi would repair it by asking the next layer (typically SQL database).
The assumption about requested and returned counts prevents the repair but returnes completely empty objects which lead to follow-up errors.