- If the output is invalid/unspendable, upon unlock it will be
deleted from the locked outputs table and then won't be used to
grow the tree. Upon reorg/pop blocks, the invalid output won't be
re-added to the locked outputs table upon trimming the tree. Thus,
it's possible for an invalid/unspendable output to not be present
in the locked outputs table upon remove.
- trim_tree now re-adds trimmed outputs back to the locked outputs
table. remove_output then deletes from the locked output table.
- Since outputs added to the tree in a specific block may have
originated from distinct younger blocks (thanks to distinct unlock
times), we need to store the 8 byte output_id in the leaves table
as well, so that in the event of a reorg, upon removing outputs
from the tree we can add them back to the locked outputs table
in the correct order.
- Reverted back to storing output_id in locked_outputs table; it's
required to make sure outputs enter the tree in chain order I see
no other simple way.
- Removed unnecessary comments and db flags (MDB_APPENDDUP already
makes sure key/value doesn't already exist, and when inserting,
every global output id should be unique, so should never get that
error)
- We must use the output pubkey to calculate key image generator I
- Since torsion cleared outputs can be spent via ring sig today,
if we torsion clear outputs **before** calculating I, then the key
image of torsioned outputs will be different when constructing
fcmp's, effectively enabling a double spend of torsioned outputs
via ring sig before fcmp's and again via fcmp.
- Storing {output pubkey, commitment} instead of {O.x,I.x,C.x} to
save 32 bytes per output.
