At present, [zcash/zcash-android-wallet-sdk] supports Android API 27,
which bundles SQLite 3.19. SQLite support for the `TRUE` and `FALSE`
constants were introduced in SQLite 3.23, so we cannot currently use
these constants and retain support for Android API 27.
This version support limitation applies only to the `v_transactions`
and `v_tx_outputs` views, which are considered part of the public API
of this crate; other use of more recent SQLite features is fine because
they rely upon the SQLite bundled via our use of the `rusqlite` crate
and feature compatibility is verified via the unit tests of this crate.
This allows us to display additional block information when a
transparent UTXO was provided for a block that we have scanned.
Also, this ensures that memos from a wallet to itself are not
double-counted.
Co-authored-by: str4d <thestr4d@gmail.com>
Under normal usage conditions, the `transactions` table is not currently
populated for transactions involving transparent UTXOs, and so this join
was always resulting in transparent UTXO information being filtered out
from the transaction history.
Fixes [zcash/ZcashLightClientKit#1271]
This adds the `data_api::scanning::spanning_tree` module under
a new `unstable-spanning-tree` feature flag, making it available to
other implementations who want to be able to write their own storage
backends without having to reinvent the spanning tree logic.
This fixes the following bug:
Due to complexities related to non-linear scanning, checkpoints are only
added to the wallet's commitment tree in cases where there are notes
discovered within a scanned block. At present, the `shardtree` API only
makes it possible to add multiple checkpoints of the same tree state
when adding checkpoints at the chain tip, and this functionality is not
used by `zcash_client_backend` because we perform checkpoint insertion
in batches that may contain gaps in the case that multiple blocks
contain no Sapling notes. While it would be possible to fix this by
altering the `shardtree` API to permit explicit insertion of multiple
checkpoints of the same tree state at a given note position, this fix
takes a simpler approach.
Instead of ensuring that a checkpoint exists at every block and
computing the required checkpoint depth directly from the minimum number
of confirmations required when attempting a spend, we alter the
`WalletCommitmentTrees` API to allow internal information of the note
commitment tree to be used to determine this checkpoint depth, given the
minimum number of commitments as an argument. This allows us to select a
usable checkpoint from the sparse checkpoint set that resulted from the
sparse insertion of checkpoints described above.