Map and list types are now unconditionally initialised during an Into()
call to ensure that the only data within them after the operation is
that added by the Into() function.
Prior to this change, map/list types would likely not be cleared prior
to the data being inserted into them with a few exceptions. Nil
pointers or maps/lists that were not sufficient in capacity would be
reinitialised and used to replace the existing backing data store. In
some cases this wouldn't occur meaning any residual data existing in the
container before the Into() call could persist after the data copy
completes. This behaviour is wildly inconsistent and not ideal in the
vast majority of cases. It should be assumed that the Into() call will
preserve nothing and always produce a consistent and deterministic
output.
Signed-off-by: Joe Groocock <me@frebib.net>
83c5ab318b