Now that the release commits are created, we can unhide this ahead of
the subsequent Orchard-supporting releases.
This reverts commit zcash/librustzcash@6161709441.
Due to `zcash_keys` being in `zcash_client_backend`'s public API, their
unstable APIs are a common API surface (as they were before `zcash_keys`
was extracted).
This can be reverted once `zcash_keys` types with unstable APIs are not
being re-exported from `zcash_client_backend`.
This change makes it easier for third parties to make use of the Unified
key infrastructure without incurring a dependency upon the rest of the
`zcash_client_backend` interfaces.
We plan to also introduce a similar flag to gate access to Sapling
functionality. Since introduction of Orchard functionality is still
nascent, it's the correct time to introduce this isolation, before
there's more functionality that needs to be isolated in this fashion.
Prior to this change, it's necessary to implement the entirety of the
`WalletRead` trait in order to be able to use the input selection
functionality provided by `zcash_client_backend::data_api::input_selection`.
This change factors out the minimal operations required for transaction
proposal construction to better reflect the principle of least authority
and make the input selection code reusable in more contexts.
In order to minimize the operations of the newly-created `InputSource`
and `ShieldingSource` traits, this change also removes the
`min_confirmations` field from transaction proposals, in favor of
storing explicit target and anchor heights. This has the effect of
limiting the lifetime of transaction proposals to `PRUNING_DEPTH -
min_confirmations` blocks.
The MSRV for the main crates is 1.65, which is higher than the Rust
version that stabilised workplace dependencies (1.64). The implicit MSRV
for the component crates is still lower than this, so we don't migrate
these crates.
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 also removes the zcash_client_sqlite-specific database
initialization procedures in favor of a standardized approach using the
methods available via the data access API.
Kris Nuttycombe
Jack Grigg
Nate Wilcox