* ZIP-401 weighted random mempool eviction
* rename zcash.mempool.total_cost.bytes to zcash.mempool.cost.bytes
Co-authored-by: teor <teor@riseup.net>
* Remove duplicated lines
* Add cost() method to UnminedTx
Update serialization failure messages
* More docs quoting ZIP-401 rules
* Change mempool::Storage::new() to handle Copy-less HashMap, HashSet
* mempool: tidy cost types and evict_one()
* More consensus rule docs
* Refactor calculating mempool costs for Unmined transactions
* Add a note on asympotic performance of calculating weights of txs in mempool
* Bump test mempool / storage config to avoid weighted random cost limits
* Use mempool tx_cost_limit = u64::MAX for some tests
* Remove failing tests for now
* Allow(clippy::field-reassign-with-default) because of a move on a type that doesn't impl Copy
* Fix mistaken doctest formatting
Co-authored-by: Conrado Gouvea <conrado@zfnd.org>
* Increase test timeout for Windows builds
Co-authored-by: teor <teor@riseup.net>
Co-authored-by: Conrado Gouvea <conrado@zfnd.org>
* Limit tx size
Zebra now limits the transaction size in the `zcash_deserialize()` method for
`Transaction`.
* Remove unused error variants (#2941)
Co-authored-by: Conrado Gouvea <conrado@zfnd.org>
* Limit tx size
Zebra now limits the transaction size in the `zcash_deserialize()` method for
`Transaction`.
* Test the tx deserialization limit
Co-authored-by: Conrado Gouvea <conrado@zfnd.org>
* Increment the crates that have new commits since the last version
* Increment the crates that depend on crates that have changed
* Increment the version of `zebra-script`
* Use the `zebrad` version in the `zebra-network` user agent string
* Use the `v1.0.0-alpha.19` git tag in `README.md`
* Copy the draft changelog into `CHANGELOG.md`
* Delete bumps
* Update CHANGELOG.md
Co-authored-by: teor <teor@riseup.net>
* Add newly merged PRs
Co-authored-by: teor <teor@riseup.net>
* Create a new VerifiedUnminedTx containing the miner fee
* Use VerifiedUnminedTx in mempool verification responses
And do a bunch of other cleanups.
* Use VerifiedUnminedTx in mempool download and verifier
* Use VerifiedUnminedTx in mempool storage and verified set
* Impl Display for VerifiedUnminedTx, and some convenience methods
* Use VerifiedUnminedTx in existing tests
* Limit the size of rejection lists when there is a spend conflict
Previously, `insert` would return early with an error,
and skip limiting the rejection list sizes.
* Use prop_assert macros in proptests, rather than assert
* Add `HashSet`s to help spend conflict detection
Keep track of the spent transparent outpoints and the revealed
nullifiers.
Clippy complained that the `ActiveState` had variants with large size
differences, but that was expected, so I disabled that lint on that
`enum`.
* Clear the `HashSet`s when clearing the mempool
Clear them so that they remain consistent with the set of verified
transactions.
* Use `HashSet`s to check for spend conflicts
Store new outputs into its respective `HashSet`, and abort if a
duplicate output is found.
* Remove inserted outputs when aborting
Restore the `HashSet` to its previous state.
* Remove tracked outputs when removing a transaction
Keep the mempool storage in a consistent state when a transaction is
removed.
* Remove tracked outputs when evicting from mempool
Ensure eviction also keeps the tracked outputs consistent with the
verified transactions.
* Refactor to create a `VerifiedSet` helper type
Move the code to handle the output caches into the new type. Also move
the eviction code to make things a little simpler.
* Refactor to have a single `remove` method
Centralize the code that handles the removal of a transaction to avoid
mistakes.
* Move mempool size limiting back to `Storage`
Because the evicted transactions must be added to the rejected list.
* Remove leftover `dbg!` statement
Leftover from some temporary testing code.
Co-authored-by: teor <teor@riseup.net>
* Remove unnecessary `TODO`
It is more speculation than planning, so it doesn't add much value.
Co-authored-by: teor <teor@riseup.net>
* Fix typo in documentation
The verb should match the subject "transactions" which is plural.
Co-authored-by: teor <teor@riseup.net>
* Add a comment to warn about correctness
There's a subtle but important detail in the implementation that should
be made more visible to avoid mistakes in the future.
Co-authored-by: teor <teor@riseup.net>
* Remove outdated comment
Left-over from the attempt to move the eviction into the `VerifiedSet`.
* Improve comment explaining lint removal
Rewrite the comment explaining why the Clippy lint was ignored.
* Check for spend conflicts in `VerifiedSet`
Refactor to avoid API misuse.
* Test rejected transaction rollback
Using two transactions, perform the same test adding a conflict to both
of them to check if the second inserted transaction is properly
rejected. Then remove any conflicts from the second transaction and add
it again. That should work, because if it doesn't it means that when the
second transaction was rejected it left things it shouldn't in the
cache.
* Test removal of multiple transactions
When removing multiple transactions from the mempool storage, all of the
ones requested should be removed and any other transaction should be
still be there afterwards.
* Increase mempool size to 4, so that spend conflict tests work
If the mempool size is smaller than 4,
these tests don't fail on a trivial removal bug.
Because we need a minimum number of transactions in the mempool
to trigger the bug.
Also commit a proptest seed that fails on a trivial removal bug.
(This seed fails if we remove indexes in order,
because every index past the first removes the wrong transaction.)
* Summarise transaction data in proptest error output
* Summarise spend conflict field data in proptest error output
* Summarise multiple removal field data in proptest error output
And replace the very large proptest debug output with the new summary.
Co-authored-by: teor <teor@riseup.net>
* Update versions for zebra v1.0.0-alpha.18 release
* WIP: Initial PR list
* Remove uninteresting version bumps from CHANGELOG
* Categorise and group PRs in CHANGELOG, removing uninteresting PRs
* Further refine and categorise changelog entries
* Fix tag url
* Final changes to CHANGELOG
* Add a changelog description
* Spacing
* Clarify and fix changelog PR descriptions
* Add PRs that are about to be merged
* More slight clarifications
* Spacing
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Co-authored-by: teor <teor@riseup.net>
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Check return value of zcash_script_new_precomputed_tx
* Set the NU5 testnet activation height to 1_590_000
* Apply suggestions from code review
Co-authored-by: teor <teor@riseup.net>
* Update Nu5 constants to new values
* Update ZIP-244 test vectors for new branch ID
* Squashed commit of the following:
commit bdb120a249
Author: Deirdre Connolly <durumcrustulum@gmail.com>
Date: Tue Oct 5 11:54:01 2021 -0400
Use pallas::Base::from_str_vartime() in sinsemilla tests
commit e99fa49258
Author: Deirdre Connolly <durumcrustulum@gmail.com>
Date: Tue Oct 5 11:45:24 2021 -0400
Compiles
commit a520018114
Author: Deirdre Connolly <durumcrustulum@gmail.com>
Date: Tue Oct 5 10:15:17 2021 -0400
Incomplete upgrade of deps
* Squashed commit of the following:
commit 8d1b76ec5626517817c3a4d9f3950acc90a359df
Author: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Date: Tue Oct 5 04:02:26 2021 +0000
Update `zcash_script` to support V5 transactions
Use a newer version of `zcash_script` that has been updated to support
V5 transactions.
commit 371233628ae61e0c25d6ba8f31d9dba42823becb
Author: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Date: Tue Oct 5 03:06:20 2021 +0000
Update Zcash dependencies
Update some Zcash crates:
- `halo2`
- `incrementalmerkletree' (patch version)
- `orchard` (patch version)
- `zcash_history` (patch version)
- `zcash_note_encryption` (patch version)
- `zcash_primitives` (patch version)
And also update the `group` dependency so that the code remains
compatible.
commit de5cf1ec40c3fc08670fc971cdf3e65e13d9f4c7
Author: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Date: Tue Oct 5 03:04:13 2021 +0000
Update error message assertion
Use the updated message for the expected error variant.
* Update `zcash_script` to support V5 transactions
Use a newer version of `zcash_script` that has been updated to support
V5 transactions.
Co-authored-by: Conrado Gouvea <conrado@zfnd.org>
Co-authored-by: teor <teor@riseup.net>
* Rename type parameter to be more explicit
Replace the single letter with a proper name.
* Remove imports for `Request` and `Response`
The type names will conflict with the ones for the mempool service.
* Attach `Mempool` service to the `Crawler`
Add a field to the `Crawler` type to store a way to access the `Mempool`
service.
* Forward crawled transactions to downloader
The crawled transactions are now sent to the transaction downloader and
verifier, to be included in the mempool.
* Derive `Eq` and `PartialEq` for `mempool::Request`
Make it simpler to use the `MockService::expect_request` method.
* Test if crawled transactions are downloaded
Create some dummy crawled transactions, and let the crawler discover
them. Then check if they are forwarded to the mempool to be downloaded
and verified.
* Don't send empty transaction ID list to downloader
Ignore response from peers that don't provide any crawled transactions.
* Log errors when forwarding crawled transaction IDs
Calling the Mempool service should not fail, so if an error happens it
should be visible. However, errors when downloading individual
transactions can happen from time to time, so there's no need for them
to be very visible.
* Document existing `mempool::Crawler` test
Provide some depth as to what the test expect from the crawler's
behavior.
* Refactor to create `setup_crawler` helper function
Make it easier to reuse the common test setup code.
* Simplify code to expect requests
Now that `zebra_network::Request` implement `Eq`, the call can be
simplified into `expect_request`.
* Refactor to create `respond_with_transaction_ids`
A helper function that checks for a network crawl request and responds
with the given list of crawled transaction IDs.
* Refactor to create `crawler_iterator` helper
A function to intercept and respond to the fanned-out requests sent
during a single crawl iteration.
* Refactor to create `respond_to_queue_request`
Reduce the repeated code necessary to intercept and reply to a request
for queuing transactions to be downloaded.
* Add `respond_to_queue_request_with_error` helper
Intercepts a mempool request to queue transactions to be downloaded, and
responds with an error, simulating an internal problem in the mempool
service implementation.
* Derive `Arbitrary` for `NetworkUpgrade`
This is required for deriving `Arbitrary` for some error types.
* Derive `Arbitrary` for `TransactionError`
Allow random transaction errors to be generated for property tests.
* Derive `Arbitrary` for `MempoolError`
Allow random Mempool errors to be generated for property tests.
* Test if errors don't stop the mempool crawler
The crawler should be robust enough to continue operating even if the
mempool service fails to download transactions or even fails to handle
requests to enqueue transactions.
* Reduce the log level for download errors
They should happen regularly, so there's no need to have them with a
high visibility level.
Co-authored-by: teor <teor@riseup.net>
* Stop crawler if service stops
If `Mempool::poll_ready` returns an error, it's because the mempool
service has stopped and can't handle any requests, so the crawler should
stop as well.
Co-authored-by: teor <teor@riseup.net>
Co-authored-by: Conrado Gouvea <conrado@zfnd.org>
* Change assertion condition to match message
Refactor the condition so that the expression is easier to compare to
the panic message.
* Change comparison order to match panic message
Change the order of the equality so that it matches the panic message.
* mempool - support transaction expiration
* use `LatestChainTip` instead of state call
* clippy
* remove spawn task
* remove non needed async from function
* remove return value
* add a `expiry_height_mut()` method to `Transaction` for testing purposes
* fix `remove_expired_transactions()`
* add a `mempool_transaction_expiration()` test
* tidy cleanup to `expiry_height()`
* improve docs
* fix the build
* try fix macos build
* extend tests
* add doc to function
* clippy
* fix build
* start tests at block two
* Add `Transaction::spent_outpoints` getter method
Returns an iterator over the UTXO `OutPoint`s spent by the transaction.
* Add `mempool::Error::Conflict` variant
An error representing that a transaction was rejected because it
conflicts with another transaction that's already in the mempool.
* Reject conflicting mempool transactions
Reject including a transaction in the mempool if it spends outputs
already spent by, or reveals nullifiers already revealed by another
transaction in the mempool.
* Fix typo in documentation
Remove the `r` that was incorrectly added.
Co-authored-by: teor <teor@riseup.net>
* Specify that the conflict is a spend conflict
Make the situation clearer, because there are other types of conflict.
Co-authored-by: teor <teor@riseup.net>
* Clarify that the outpoints are from inputs
Because otherwise it could lead to confusion because it could also mean
the outputs of the transaction represented as `OutPoint` references.
Co-authored-by: teor <teor@riseup.net>
* Create `storage::tests::vectors` module
Refactor to follow the convention used for other tests.
* Add an `AtLeastOne::first_mut` method
A getter to allow changing the first element.
* Add an `AtLeastOne::push` method
Allow appending elements to the collection.
* Derive `Arbitrary` for `FieldNotPresent`
This is just to make the code that generates arbitrary anchors a bit
simpler.
* Test if conflicting transactions are rejected
Generate two transactions (either V4 or V5) and insert a conflicting
spend, which can be either a transparent UTXO, or a nullifier for one of
the shielded pools. Check that any attempt to insert both transactions
causes one to be accepted and the other to be rejected.
* Delete a TODO comment that we decided not to do
Co-authored-by: teor <teor@riseup.net>
* Fix an incorrect assertion when the block locator is at the tip
This might have been triggered by receiving block hash gossips
from the new Zebra code.
* Add missing tests for zebra-state requests and responses
Specifically:
* `BlockLocator` (populated state only)
* `FindBlockHashes`
* `FindBlockHeaders`
* Test `FindBlock*` before and after the current block
* Add a specific test for bug #2789
* Refactor collect_best_chain_hashes to avoid manual index calculations
* Reword a comment
Co-authored-by: Alfredo Garcia <oxarbitrage@gmail.com>
* Use `TipAction::Reset` for initialization and out-of-order blocks
Needs tests for:
- cloning a `ChainTipChange` resets the cloned instance
- skipped updates reset the cloned instance
- changing forks resets the cloned instance
* Use `TipAction::Reset` for network upgrade activation blocks
* Use an `if` expression
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Another if expression
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Rename ChainTipReceiver to CurrentChainTip
`fastmod ChainTipReceiver CurrentChainTip zebra*`
* Update chain tip documentation and variable names
* Basic chain tip change implementation, without resets
Also includes the following name changes:
```
fastmod CurrentChainTip LatestChainTip zebra*
fastmod chain_tip_receiver latest_chain_tip zebra*
```
* Clarify the difference between `LatestChainTip` and `ChainTipChange`
* Store precalculated transactions in an `Arc`
Transaction `Hash`es are 32 bytes,
and the minimun transparent transaction size is 54 bytes.
So a full 2MB block can create 1.1MB of transaction hashes.
We use an `Arc` to avoid repeatedly cloning that much data.
* Remove the unused `Block` from `ChainTipBlock`
This drops the block as soon as it isn't needed any more.
Previously, it would stick around until every `ChainTipReceiver`
dropped their `ChainTipBlock`, even if they didn't use the `Block`
at all.
* Re-use finalized blocks for chain tip updates
This avoids serializing and deserializing blocks from the finalized state.
* Optimise tip sender equality checks
* Re-use precalculated block hashes and heights for chain tip updates
* Add chain tip mined transaction IDs
* Doc comment typo
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Always prefer the non-finalized tip in ChainTipSender
This significantly simplifies the internal implementation of ChainTipSender.
Also make the methods and types a bit more generic.
* Update ChainTipSender with blocks, not heights
Also fix a bug where queued non-finalized blocks would clear the chain tip.
* Provide a best tip hash in ChainTip receivers
* Skip finalized blocks once the non-finalized state is active
* Add tip hash and NoChainTip tests
* Remove a redundant finalized tip update
* Skip `None` updates to the finalized tip
The finalized and non-finalized tips never update to `None`
once they have added at least one block.
* Stop committing finalized queued blocks if there is an error
Also return the highest committed queued block.
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Rename BestTipHeight so it can be generalised to ChainTipSender
`fastmod BestTipHeight ChainTipSender zebra*`
For senders:
`fastmod best_tip_height chain_tip_sender zebra*`
For receivers:
`fastmod best_tip_height chain_tip_receiver zebra*`
* Rename best_tip_height module to chain_tip
* Wrap the chain tip watch channel in a ChainTipReceiver type
* Create a ChainTip trait to avoid tricky crate dependencies
And add convenience impls for optional and empty chain tips.
* Use the ChainTip trait in zebra-network
* Replace `Option<ChainTip>` with `NoChainTip`
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Add `Arc<Transaction>` conversions for Transaction IDs
* Use UnminedTxId as the transaction verifier response type
* Use UnminedTx in transaction verifier mempool requests
* Refactor is_mempool into a transaction verifier request method
* Order derives in alphabetical order
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
* add value balances to non finalized state
* fix 2 tests
* fix remaining constrain issues in tests
* extend value pool test to non finalized
* WIP: fix tests after adding value pools to non-finalized state (#2647)
* Update Chain::eq_internal_state with Chain.value_balance
Also increase the number of cases in its tests,
because they didn't detect this bug.
* Calculate the chain value pool change before `Chain::push`
Code
- store the chain value pool change in `ContextuallyValidBlock`
- convert `PreparedBlock` to `ContextuallyValidBlock` using `with_block_and_spent_utxos`
(rather than `from` or `into`)
- replace `block_utxos` with `new_outputs` in `PreparedBlock`
- replace `block_utxos` with `chain_value_pool_change` in `ContextuallyValidBlock`
Tests
- create test methods for `PreparedBlock` and `ContextuallyValidBlock`
- use `test_with_zero_chain_pool_change` or `test_with_zero_spent_utxos`
to make tests pass
* fix conflicts
* build `set_current_value_pool()` only for tests
* remove redundant cfgs
* change cfg of set_current_value_pool()
* Clarify some chain field documentation
* Fix bugs in the non-finalized chain value pool calculations
1. Only revert the chain value pool balances when the tip is popped.
Don't modify them when the root is finalized.
2. Only update or revert the chain value pool balances once per block.
(Previously, the block changes were multiplied by the number of *transactions*.)
And make corresponding changes to method names and documentation.
* Add extra proptests to try to identify value balance failures
* Simplify some transaction generation code
* Add extra debugging info to value balance errors
* Actually update non-finalized chain value pools in `UpdateWith`
Previously, we were dropping the updated value pools in the `Ok` result.
So the initial (finalized) chain value pool balances were never modified.
* Rename and document value balance add methods
The names and documentation of these methods were confusing.
* Create genesis-based proptests that check chain value pools
* Increase coverage for some test vectors
* Test each chain value balance calculation for blocks 0-10
* Make continuous blockchain test errors easier to debug
* Test the exact transparent pool values for the first few blocks
Co-authored-by: Alfredo Garcia <oxarbitrage@gmail.com>
* Add validation of ZIP-221 and ZIP-244 commitments
* Apply suggestions from code review
Co-authored-by: teor <teor@riseup.net>
* Add auth commitment check in the finalized state
* Reset the verifier when comitting to state fails
* Add explanation comment
* Add test with fake activation heights
* Add generate_valid_commitments flag
* Enable fake activation heights using env var instead of feature
* Also update initial_tip_hash; refactor into progress_from_tip()
* Improve comments
* Add fake activation heights test to CI
* Fix bug that caused commitment trees to not match when generating partial arbitrary chains
* Add ChainHistoryBlockTxAuthCommitmentHash::from_commitments to organize and deduplicate code
* Remove stale comment, improve readability
* Allow overriding with PROPTEST_CASES
* partial_chain_strategy(): don't update note commitment trees when not needed; add comment
Co-authored-by: teor <teor@riseup.net>
* Improve error logging in rejection_restores_internal_state
* Summarise history tree peaks in debug output
Co-authored-by: Conrado Gouvea <conrado@zfnd.org>
Co-authored-by: Alfredo Garcia <oxarbitrage@gmail.com>
* add value pools to the database
* remove redundant genesis block check
* use update_with_chain_value_pool_change()
* remove constrains
* remove height from the database
* remove calls to chain_value_pool_change
* clippy
* use the "correct" value balances
* bump the database format
* remove everything that is not finalized state
* clippy
* rustfmt
* use all spent utxos
* add new_outputs utxos to all_utxos_spent_by_block
* remove panic
* add finalized state value pool test
* clippy
* clippy 2
* move import
* fix import
* rustfmt
Co-authored-by: teor <teor@riseup.net>
* Rename internal network requests for wide transaction IDs
fastmod TransactionsByHash TransactionsById zebra*
fastmod AdvertiseTransactions AdvertiseTransactionIds zebra*
fastmod MempoolTransactions MempoolTransactionIds zebra*
fastmod TransactionHashes TransactionIds zebra*
* Update network transaction request/response comments
* Rename a transaction hash method for wide transaction IDs
fastmod transaction_hashes transaction_ids zebra-network
* Add UnminedTxId methods and conversions for InventoryHash
* Map WtxIds to unmined transaction network messages
Also, use UnminedTxId and UnminedTx in:
* Zebra's internal request and response format, and
* external Zcash network protocol messages.
* Enable WtxId mempool inventory tracking for peers
* Further clarify transaction IDs
* Use Witnessed rather than Wide for transaction IDs
And rename narrow to legacy when it only applies to v1-v4 transactions.
Otherwise, rename it to mined ID.
* Rename a missed binding
* Remove an incorrectly named binding
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Make the `AuthDigest` display order match transaction IDs
And derive `Hash`, just like transaction IDs.
Don't derive `serde` for now, because it's not needed.
* Move transaction::Hash test to tests module
* Add a simple AuthDigest display order test
* Add a WtxId type for wide transaction IDs
* Add conversions between transaction IDs and bytes
* Use the WtxId type in external network protocol messages
* Generate chains with valid chain value pool balances
* Move MAX_PARTIAL_CHAIN_BLOCKS to zebra-chain
* Fix generated value overflow based on the maximum number of values
And split it into its own method.
* Split fix_remaining_value into smaller methods
* Remove unused methods
Co-authored-by: Alfredo Garcia <oxarbitrage@gmail.com>
* Refactor HistoryTree into NonEmptyHistoryTree and HistoryTree
* HistoryTree: use Deref instead of AsRef; remove unneeded PartialEq
* ZIP-221: Validate chain history commitments in the non-finalized state (#2301)
* sketch of implementation
* refined implementation; still incomplete
* update librustzcash, change zcash_history to work with it
* simplified code per review; renamed MMR to HistoryTree
* expand HistoryTree implementation
* handle and propagate errors
* simplify check.rs tracing
* add suggested TODO
* add HistoryTree::prune
* fix bug in pruning
* fix compilation of tests; still need to make them pass
* Apply suggestions from code review
Co-authored-by: teor <teor@riseup.net>
* Apply suggestions from code review
Co-authored-by: teor <teor@riseup.net>
* improvements from code review
* improve check.rs comments and variable names
* fix HistoryTree which should use BTreeMap and not HashMap; fix non_finalized_state prop tests
* fix finalized_state proptest
* fix non_finalized_state tests by setting the correct commitments
* renamed mmr.rs to history_tree.rs
* Add HistoryTree struct
* expand non_finalized_state protest
* fix typo
* Add HistoryTree struct
* Update zebra-chain/src/primitives/zcash_history.rs
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
* fix formatting
* Apply suggestions from code review
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
* history_tree.rs: fixes from code review
* fixes to work with updated HistoryTree
* Improvements from code review
* Add Debug implementations to allow comparing Chains with proptest_assert_eq
Co-authored-by: teor <teor@riseup.net>
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
* Apply suggestions from code review
Co-authored-by: teor <teor@riseup.net>
* Improvements from code review
* Restore blocks returned by PreparedChain since other tests broken; adjust tests with history trees
Co-authored-by: teor <teor@riseup.net>
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>