I have no memory for why this was ever there. It breaks DNSSEC
validation of large RRsets.
I can't see any DoS potential that is exposed by removing it.
If a NODATA answer is returned instead of actual data for A or AAAA
queries because of the existence of --filter-A or --filter-AAAA
config options, then mark the replies with an EDE "filtered" tag.
Basic patch by Petr Menšík, tweaked by Simon Kelley to apply onto
the preceding caching patches.
Move few patters with whine_malloc, if (successful) copy+free, to a new
whine_realloc. It should do the same thing, but with a help from OS it
can avoid unnecessary copy and free if allocation of more data after
current data is possible.
Added few setting remanining space to 0, because realloc does not use
calloc like whine_malloc does. There is no advantage of zeroing what we
will immediately overwrite. Zero only remaining space.
