Kris Nuttycombe

Clean up null pointer handling in Rust FFI

1

In a number of places in the Rust FFI, we do not adequately check for null pointers, e.g. https://github.com/zcash/zcash/pull/5569#discussion_r811433017 This style of use is common in `rustzcash.rs` and we should...

Support unified full and incoming viewing key import & export.

2

## Is your feature request related to a problem? Please describe. - Export and import of unified full viewing keys is important for maintaining a balance view for cold storage...

For a note with a nullifier that would conflict with a note in another transaction, we can ignore the conflict if the transaction has expired. For Sapling, see https://github.com/zcash/zcash/blob/007f05493a24059431ef16b3d68ae86cf06dc38d/src/wallet/wallet.cpp#L1313-L1322

Add ability to mark notes as locked to the Orchard wallet.

1

Locked notes are those that have been selected for use in a transaction that has not yet been mined. When a note is used in construction of a transaction, it...

Consider supporting Orchard spending key import & export.

1

## Is your feature request related to a problem? Please describe. Key export & import have historically been important features for supporting the use of paper wallets. ## Alternatives you've...

Tracking issue.

Backport of bitcoin/bitcoin#7906 - pick bitcoin/bitcoin@5d5e7a097a - skip bitcoin/bitcoin@e9ed6206b3 (already done) - skip bitcoin/bitcoin@8b8f87714d (already done) - skip bitcoin/bitcoin@cca221fd21 (already done) - pick bitcoin/bitcoin@563f375cde - pick bitcoin/bitcoin@9faa4902cd - pick bitcoin/bitcoin@52cbce287a...