Storage calculation doesn't handle tombstones, nor handle undefined manifest.props

[kuenishi]

around here:

riak_cs/src/riak_cs_storage.erl

Line 104 in d0501f5

AllManifests = [ binary_to_term(V)

This leads to storage calculation skips the objects where .props is undefined.

[kuenishi]

Maybe related to #840 .

[shino]

just a note: object list (v1) properly uses upgrading:
https://github.com/basho/riak_cs/blob/release/1.4/src/riak_cs_utils.erl#L510

see also : #670 #671

[kuenishi]

see also: #524

[kuenishi]

#840 identified with this issue. will open another PR.