c61df05916 Fix bip34 number parsing for Block (junderw)
Pull request description:
Fixes#3583
ACKs for top commit:
apoelstra:
ACK c61df059160d3aeef73046de28cb5d5afcb962d2; successfully ran local tests
tcharding:
ACK c61df05916
Tree-SHA512: 3fade122f98c7c9e3b2888c33479d3a9426fb35f212ccee6b89b7cd5c92d2b58c93e165d5c59eda183c0943809d7e633d929000be92b197988a3ceb0ea37514f
1649b68589 Standardize wording to `constructs a new` (Jamil Lambert, PhD)
27f94d5540 Replace `creates` with `constructs` (Jamil Lambert, PhD)
Pull request description:
As discussed in issue #3575 there are various ways of saying a new object is created.
These have all be standardized to the agreed version.
Close#3575
ACKs for top commit:
apoelstra:
ACK 1649b68589834dfe9d5b63812da3e9f0e5930107; successfully ran local tests
tcharding:
ACK 1649b68589
Tree-SHA512: 0ed9b56819c95f1fc14da1e0fdbbe03c4af2d97a95ea6b56125f72913e8d832db5d2882d713ae139d00614e651f3834a4d72528bdf776231cceb6772bf2f9963
There is a range of different wordings used in the docs of constructor
type functions.
Change all to start with `Constructs a new` or `Constructs an empty`.
In functions that act like constructors there is a mixture of the usage
of `creates` and `constructs`.
Replace all occurrences of `creates` with `constructs` in the first line
of docs of constructor like functions.
4431df18fe script: remove `unsafe` marker from slice-to-script conversions (Andrew Poelstra)
Pull request description:
The length of the slices is not a safety invariant.
Fixes#3531
ACKs for top commit:
tcharding:
ACK 4431df18fe
Tree-SHA512: 85f745058bc5bf68d312f75c53cef570ead986247ca3cb3fc54b5381dd0214e7df55c1fcb99f06e693b0b9478ec6a9785186cac56886f8007ab7b827d903bd01
The length of the slices is not a safety invariant.
Fairly large diff because I had to remove a bunch of `unsafe` blocks
around calls to this function.
Fixes#3531
We have a couple of problems:
1. There are two macros currently for fmt stuff that do similar things,
`arr_newtype_fmt_impl` and `hex_fmt_impl` - the difference is not
immediately obvious, its the way that the byte array is iterated.
2. Our hash types are missing `AsRef<[u8; len]>` and `Borrow<[u8; len]>`.
Introduce a new macro and remove a bunch of other macros. Include
extensive docs but hide the macro from public docs because its not
really for consumers of the library.
The macro requires `$crate::hex` to point to `hex-conservative`.
Note the macro is pretty generic (as in general purpose), `hashes` might
not be the right home for it. Potentially a better place would be in
`hex` itself?
This has been fixed and we use nightly to lint so we have access to the
merged fix.
Removing the attribute uncovers a bunch of real lint warnings, fix
them while we are at it.
a51768af3f key: Deprecate to_bytes (Tobin C. Harding)
3af3239ad0 script: Re-order functions (Tobin C. Harding)
db40297f87 script: deprecate to_bytes (Tobin C. Harding)
c5cd0db493 Revert the change to to_bytes (Tobin C. Harding)
dc2ca785d2 Add to_vec and deprecate to_bytes for array types (Tobin C. Harding)
a6b7ab32a8 Move impl_array_newtype to internal_macros (Tobin C. Harding)
Pull request description:
Use `to_vec` and deprecate `to_bytes`, the opposite of what we did in #2585.
For functions that return a `Vec` by first allocating use function name `to_vec`. This explicitly excludes:
- Functions that return an array (`CompressedPublicKey::to_bytes`)
- Functions that consume self and return a `Vec` without allocating (`ScriptBuf::into_bytes`)
See #3025 for discussion and consensus.
Close: #3025
ACKs for top commit:
apoelstra:
ACK a51768af3f3d4c8e138e1ded250800810bedc903; successfully ran local tests
Tree-SHA512: ee932c13ad2e09c2b76a7833b23c859df175aa307f56e673921f3ae8b5d865518c6f999749e3b627594457b3ca33301b777177ada3520cf006acc0f14e5dacf8
As we have been doing in other places deprecate `to_bytes` in favour of
`to_vec`. Note this is only for functions that return a `Vec`, the `key`
module has `CompressedKey::to_bytes` still as it returns an array.
During this release cycle we deprecated `to_vec` in favour of
`to_bytes`, we have since reversed our position on the name.
Remove the deprecation of `to_bytes` from the three types that had it
and use `to_vec`.
In the `script` module remove the wildcards and re-export stuff from
`self` explicitly in both `primitives` and `bitcoin`.
Internal change only, everything is re-exported.
The current feature gating is wrong, this bug is unreleased because it
was introduced #2585.
The `impl_array_newtype` macro is only used in the `bitcoin` crate, it
does not need to be in `internals`. Also, other crates have an `alloc`
feature which `bitcoin` does not have so if we ever need it in other
places we'll need a duplicate with the correct feature gating anyways.
Move the macro to `bitcoin::internal_macros` and remove the incorrect
`alloc` feature gating.
WARNING: This is not like all the other extension traits.
Because of the use of generics on various `Transaction` methods it is
not easily possible to use the `define_extension_trait` macro.
Manually create the extension traits (public and private) for the
`Transaction` type. This is quite ugly but c'est la vie
(Includes two in the `transaction` module and one in the
`consensus_validation` module.)
Currently `script_pubkey_lens` returns a generic `Iterator` using `impl`
syntax. This syntax is not supported in traits and we want to move the
function to the soon-to-be-added `TransactionExt` trait.
Add a struct to hold the iterator returned by `Map`, this is ugly but
its the least ugly thing I could come up with.
Split the `Transaction` impl block into three parts:
- The bits going to `primitives`
- The bits staying in a public extension trait
- The bits staying in a private extension trait
Internal change only.
It is acceptable to use a wildcard import in bench code for the same
reasons it is acceptable in the `tests` module.
In preparation for introducing extension traits in the `transaction`
module use wildcard import in the module's bench code.
66da2266e2 Explicitly re-export stuff from crates down the stack (Tobin C. Harding)
Pull request description:
Up until recently we were using wildcard re-exports for types moved to `units` and `primitives`. We have decided against doing so in favour of explicit re-exports.
Audit `units` and `primitives` using `git grep 'pub enum'` (and `struct`) and explicitly re-export all types.
Remove all wildcards except for the re-exports from `opcodes`, there are too many opcodes, explicitly re-exporting them does not aid clarity.
ACKs for top commit:
apoelstra:
ACK 66da2266e26dfe53947c4606e9d18620931e93cf; successfully ran local tests
Tree-SHA512: 74717f8b127e975e3d131aab884bdfe78e699d88b7ee1db7731ad117437d37684285264001cf6b2182eb1e565171167695e00c4b6aef28a3e26b69d9cebfbb74
Up until recently we were using wildcard re-exports for types moved to
`units` and `primitives`. We have decided against doing so in favour of
explicit re-exports.
Audit `units` and `primitives` using `git grep 'pub enum'` (and
`struct`) and explicitly re-export all types.
Remove all wildcards except for the re-exports from `opcodes`, there are
too many opcodes, explicitly re-exporting them does not aid clarity.
5633b10f5c Manually implement compute_txid and compute_wtxid (Tobin C. Harding)
Pull request description:
We would like to move the `Transaction` type over to `primitives` including the `compute_txid` and `compute_wtxid` functions however currently the implementations, as expected, use `Encodable`.
Manually implement `Encodable` by hashing all the fields in the correct order.
Note we have unit tests already that check the output string of the txid returned so these act as regression tests for this patch.
ACKs for top commit:
apoelstra:
ACK 5633b10f5c826e0b2ac47dd85f697f12710898d7; successfully ran local tests; nice
Tree-SHA512: 66a955d3d896801cfefe0388aade3a31f22fac5b6da7b996be61f374b93772487c0c203320aaf5165fcef26874564bce375ecb364175b0a01c3008b7ea8db981
We would like to move the `Transaction` type over to `primitives`
including the `compute_txid` and `compute_wtxid` functions however
currently the implementations, as expected, use `Encodable`.
Manually implement `Encodable` by hashing all the fields in the correct
order.
Note we have unit tests already that check the output string of the txid
returned so these act as regression tests for this patch.
In preparation for moving the `TxIn` over to `primitives` make the
private `TxIn::BASE_WEIGHT` associated const into a file-scoped constant
because the other alternative is to make it public.
bbffa3db43 Remove the IO error from DecodeError (Tobin C. Harding)
713196be0d Return DeserError from encode::deserialize (Tobin C. Harding)
33566ac58c Split encode::Error into two parts (Tobin C. Harding)
b04142c745 Add encode::Error::MissingData variant (Tobin C. Harding)
5a42ef2850 Do not manually map IO error (Tobin C. Harding)
efd7f9f06c Add error constructor parse_failed_error (Tobin C. Harding)
ebfef3f114 Return generic error as Some (Tobin C. Harding)
a6254212dc Move consensus error code to submodule (Tobin C. Harding)
Pull request description:
The `consensus::deserialize` and `consensus::deserilaize_partial` functions should not return an I/O error. Doing so causes various other error types to include an `io::Error` and the `io::Error` is an annoying type to work with.
This PR is a bunch of steps, and it took me a good while with quite a bit of backtracking to get here. As such you may want to review the final state before looking at each patch.
The `consensus` errors can be further cleaned up but I'd prefer not to spend more time on this unless it has some chance of merging.
ACKs for top commit:
apoelstra:
ACK bbffa3db43802b30d23259c0372f16a877a0ef8b; successfully ran local tests
Tree-SHA512: 522fdd29638a214cb7fcee29dd3b9f5c846f041fba087a56a91b83e6d85f033cbed95f659dc4321cd4596943ff233bdd184cdfbfcc787fe89172bb93aa4ab186
The `consensus::encode::Error` contains an IO error but reading from a
buffer only ever errors for EOF. We converted all instances of EOF to
`MissingData` already so now we can split the IO error apart from the
actual encoding errors variants.
The `encode::Error::ParseFailed` variant holds an inner string, this is
suboptimal.
In an effort to patch the `encode::Error` while mimizing the diffs
required add a helper function that creates the variant. The benefit is
that later patches that effect this variant will only need to update the
constructor function and not every call site.
Internal change only.
The extension traits are temporary just while we try to stabalize
`primitives`, they are not intended to be implemented by downstream.
Seal the extension traits so that downstream crates cannot implement
them.
Fix: #3231
c1eccfde25 Move Witness to primitives (Tobin C. Harding)
6ce76cd7c8 Add unstable constructor to Witness (Tobin C. Harding)
Pull request description:
Patch 1 introduces a new policy to the codebase, we use `foo__unstable` for public unstable functions and there are zero semver guarantees if you call these functions.
Patch 2 does the move.
Close#3406
ACKs for top commit:
apoelstra:
ACK c1eccfde25fd4c2b19e7ec6759352b46ac246113; successfully ran local tests
Tree-SHA512: 2388066be2b6bb2cf3d6757c8f6334beeda6115ef1ce7c537955d32aa5e466add5162d0d2adee27f416fe622fc93c4e94bd848326463ee55e08d1c0f4e03719c
Move the `Witness` over to `primitives` leaving behind any method that
takes or returns a `Script` or a signature.
Includes addition of a feature gate to unit test.
In preparation for moving the `Witness` to `primitives` we need a way to
construct the `Witness` when decoding. In order to maintain the current
performance and not introduce additional allocations we need to be able
to construct a `Witness` from the content buffer, this leaks the
implementation details of `Witness`.
Add a clearly marked unstable constructor to create a `Witness` from
parts. This introduces the concept of `foo__unstable` function names;
add a section to the README describing unstable functions and semver
guarantees.
ff64fa3c46 Move block::Header to primitives (Tobin C. Harding)
65925117a0 Manually implement block::Header::block_hash (Tobin C. Harding)
b02ab25342 Add regression test for block_hash function (Tobin C. Harding)
5614694b69 block: Remove wildcard re-export (Tobin C. Harding)
Pull request description:
- Patch 1: Trivial preparation.
- Patch 2 and 3: Reduce the API surface in a disappointing way due to the orphan rule.
- Patch 4: Do the move.
ACKs for top commit:
apoelstra:
ACK ff64fa3c46 successfully ran local tests; nice!
Tree-SHA512: 8d93de4a12c9f71f9dfbdc023fd8defb78f7d3da995490af8f83a927c2ca6338dd236bc08691311dc7345183fb6d0be61eedce3e4424d4060be2de934facd60a
We want to move the `block_hash` function to `primitives` but it uses
`Encodable` which currently lives in `bitcoin`. Just implement it
manually.
We added a regression test already in a previous commit to check that
this is correct.
We had an initial go at this but we didn't do the `Hash` trait method.
In order to do so we need to hack the serde code a fair bit, note the
public visitor types.
Recently we deprecated `to_vec` in favour of `to_bytes` however we
continued to use `to_vec` in a few places. This wasn't noticed because
of our usage of `TBD` in the `deprecated` attribute.
Use `to_bytes` instead of `to_vec`.
d649c06238 Move script types to primitives (Tobin C. Harding)
ec4635904b Inline bytes_to_asm_fmt into Script::Display impl (Tobin C. Harding)
Pull request description:
First patch removes `bytes_to_asm_fmt` as requested by Kix here: https://github.com/rust-bitcoin/rust-bitcoin/pull/3194#discussion_r1756557768
Second patch does the move. The move is minimal but there is quite a bit of code moved in `script/mod.rs` - I believe it is as minimal as required as well.
ACKs for top commit:
apoelstra:
ACK d649c06238 successfully ran local tests
Tree-SHA512: 329a23948ac5617402a724b734d81cde8ab1f57ddd4860f858880618e260ea8b5cc89315de1fd93ae32787d5e8508fd604a41f003b1f5772a773b5b1648d382c
9e6b8faf84 feat: add version three variant to transaction version (Rob N)
Pull request description:
Topologically restricted transactions are now considered standard as of Bitcoin 28.0.
ACKs for top commit:
apoelstra:
ACK 9e6b8faf84 successfully ran local tests
tcharding:
ACK 9e6b8faf84
Tree-SHA512: 289b986304e206802f04cee6607087167f6d91d8a81d4fc49ed01c430f4f6ad00b44646fbefdd000148fc5bfe2d257f92b386bfaf4405c482e4e438d830ab586
a250c8eee4 Fix unused imports (Shing Him Ng)
Pull request description:
Found some unused imports while working on something unrelated
ACKs for top commit:
apoelstra:
ACK a250c8eee4 successfully ran local tests
tcharding:
ACK a250c8eee4
Tree-SHA512: ffa4fcddb91c849df7885a6d734405ab704e0353293fa3462a981e179ea49091990df4482eee2324e7b5ef250a0890b2e8983d53ec288ca6e8ada77e30c102dc
0c824c9c68 Implement Arbitrary for Block (Shing Him Ng)
Pull request description:
Implementing `Arbitrary` for `Block` and its child types
ACKs for top commit:
apoelstra:
ACK 0c824c9c68 successfully ran local tests
tcharding:
ACK 0c824c9c68
Tree-SHA512: 407acd4155ca7496bf7c59af19f103b22b4c74dd013c2e2c42aae690ba7264ecd42ed034355cf8895f2532f8cef77dfdbeac250301a6973afd5f3920be7e4310
323e706113 Add rustfmt config option style_edition (Tobin C. Harding)
2e4179ed0f Run the formatter (Tobin C. Harding)
2c40b4f4ec Configure formmater to skip read_compact_size (Tobin C. Harding)
Pull request description:
`rustfmt` is emitting:
Warning: the `version` option is deprecated. Use `style_edition` instead.
As suggested add a config option and set it to 2021.
- Patch 1: Manually configure rustfmt to skip some code
- Patch 2: Run the formmater with current configuration
- Patch 3: Add the new config option (remove old one), introduces no new formatting requirements
ACKs for top commit:
apoelstra:
ACK 323e706113 successfully ran local tests
Tree-SHA512: 7f80cc89f86d2d50936e51704344955fa00532424c29c0ee3fae1a6836e24030f909b770d28da13e1c5efde3d49ad7d52c6d909d120fb09c33abf1755f62cd38
70264bfcec Move block::Version to primitives (Tobin C. Harding)
819d8d72e8 Stop using private Version constructor (Tobin C. Harding)
Pull request description:
This is a straight up move of the whole type because there are only three methods, a getter, a setter, and `is_signalling_soft_fork`.
If we use an extension trait for `is_signalling_soft_fork` then we have to make the two private associated consts public which is in my opinion worse.
Patch 1 is preparation, use getter/setter, patch 2 does the move.
ACKs for top commit:
apoelstra:
ACK 70264bfcec successfully ran local tests
Tree-SHA512: b61e853b4b96cb1cc56c7bfb67cc6c3ba7c631cb9e540393eb780dcf63bd2d934058794f2ac0145b4b5404a6a68887c3a1d225b2d87b57415474c05d3ef2811f
aa1fd5f44c Update the doc for InputWeightPrediction::weight() (spacebear)
8fd53c8ecf Add nested P2WPKH helpers to InputWeightPrediction (spacebear)
Pull request description:
Following up on https://github.com/rust-bitcoin/rust-bitcoin/issues/630#issuecomment-2392050517.
I amended the docstring on `InputWeightPrediction::weight()` to clarify that it only returns the signature weight. I'm not sure what the rationale was for only returning partial input weight, and if there are any arguments against something like `InputWeightPrediction::total_weight()` which returns `self.weight() + Weight::from_non_witness_data_size(32 + 4 + 4)` (and maybe deprecate `weight()` eventually to prevent misuse).
ACKs for top commit:
apoelstra:
ACK aa1fd5f44c successfully ran local tests
tcharding:
ACK aa1fd5f44c
Tree-SHA512: 9bdd882164a80a1a1a44c593750aa59e470f2928c0380d4d53a0409add597844cf11945785264ebd6b281029b3f2ef1be6c77e1e9cd148192dbd601df30a60ae
This is a straight up move of the whole type because there are only
three methods, a getter, a setter, and `is_signalling_soft_fork`.
If we use an extension trait for `is_signalling_soft_fork` then we
have to make the two private associated consts public which is in my
opinion worse.
In preparation for moving the `block::Version` type over to `primitives`
stop using the private constructor and inner field. Use the public
getter/setter instead (`to_consensus`and `from_consensus` respectively).
We would like to move the `Witness` to `primitives` however in the
`Encodable` implementation we are currently accessing the private
`content` field.
Instead of accessing `content` we can iterate over the witness elements
and write each individually, this has the same result but does a bunch
of additional calls to `Write::write_all` (via `emit_slice`).
This patch effects performance negatively but makes no changes to the
encoding.
The `Witness::push_slice` function is called by `Witness::push` after
calling `as_ref`, hence is equivalent for all types that implement
`AsRef<[u8]>`. Also, `push_slice` is a private method on `Witness`.
In preparation for moving `Witness` over to `primitives` stop using
`push_slice` in favour of `push`.
Internal change only.
In preparation for moving the `Witness` oven to `primitives` use the
`len` function instead of accessing the `witness_elements` field.
No logic change, `Witness::len()` returns `witness_elements`.
da0795e590 primitives: Use doc links for OutPoint (Tobin C. Harding)
b079cbafee Move OutPoint to primitives (Tobin C. Harding)
f5c46cd411 Introduce OutPoint extension traits (Tobin C. Harding)
7e5bd5048d Remove docs on deprecated is_null function (Tobin C. Harding)
97b20a2316 Add additional impl block to OutPoint (Tobin C. Harding)
Pull request description:
Just the minimal move of `OutPoint` to `primitives`.
The last patch closes#3347
ACKs for top commit:
apoelstra:
ACK da0795e590 successfully ran local tests
Tree-SHA512: dced5a6d6bc6af0ce8b4ae4e52c04b45c85eb77a24bb25762ba8ab7deeab1e6b392cc4b258bb14218e8a2af999715dfed45ba94599cb16963a843995a7475917
5fab6b178f Rename iter len unit test (Tobin C. Harding)
f6a74ef4af Refactor the serde Witness unit tests (Tobin C. Harding)
9860453b5b Improve Witness consensus encode unit test (Tobin C. Harding)
7e2899d310 Improve Witness::push unit test (Tobin C. Harding)
fe967279e5 Improve witness unit tests for single empty element (Tobin C. Harding)
Pull request description:
In preparation for moving the `Witness` type over to `primitives` refactor and improve all the unit tests that will be moved, do not touch the ones that will stay behind.
The first five patches are from #3406, the last is just a re-name of the test function I tried to refactor in ac6fe3a881
ACKs for top commit:
apoelstra:
ACK 5fab6b178f successfully ran local tests
Tree-SHA512: bc00f81e3c5cc92ae58dd2fc876d368a487ae6c08cc0735d7227c3a89287e321dbfb5b571b951d0616af0ec7cf9a0ea2d0e724645b1c419933a212ece80a0fbf
2d8c613340 Move the block hash types to primitives (Tobin C. Harding)
6b9429ac7b Remove BlockHash::all_zeros (Tobin C. Harding)
20d8dbd586 Add missing line of whitespace (Tobin C. Harding)
Pull request description:
As an initial step in moving the `block` module, just move over the hash types `BlockHash` and `WitnessCommitment`.
Patch 2 introduces an associated const `BlockHash::GENESIS_PREV_BLOCKHASH` and removes `all_zeros`.
ACKs for top commit:
apoelstra:
ACK 2d8c613340 successfully ran local tests
Tree-SHA512: 64aa0ae81e1c8ab1b5d4cd8cd28e6ef04ed01bf79175dc5b1fd607a6f0967e06b0aaf4c10ad368e2b327edcad3705187b6643d5ca8647716319424f19a838ba1
18d8b0e469 Replace VarInt type with ReadExt and WriteExt functions (Steven Roose)
003db025c1 Return encoded length from WriteExt::emit_slice (Steven Roose)
Pull request description:
This the meat and potatoes out of Steven's work in #2133 and also closes#1016
ACKs for top commit:
apoelstra:
ACK 18d8b0e469 successfully ran local tests
Tree-SHA512: 2df96c91e0fbfdc87158bde9bbdd9565f67e3f66601697d0e22341416c0cd45dd69d09637393993f350354a44031bead99fd0d2f006b4fc6e7613aedc4b0a832
Move the `OutPoint` type and associated code over to `primitives`. Take
the opportunity to re-order the code so the file reads like a story,
things are implemented below where they are called.
Our `define_extension_trait` macro cannot handle examples in rustdocs,
since these docs are on the deprecated `OutPoint::is_null` function just
remove them.
In preparation for moving the `OutPoint` to `primitives` add an
additional impl block that holds everthing that will stay here in
`bitcoin`.
Internal change only.
Rust convention is to not use `test_` prefix on unit tests. Also this
unit test is testing that the `ExactSizedIterator` trait is implemented
and working.
Re-name unit test to `exact_sized_iterator`.
In preparation for moving unit tests to `primitives` give the serde
tests some love by doing:
- Split them up to do one thing only
- Round trip arbitrary witness
- Use better names
Make an effort to clean up the encoding unit test, by doing:
- Remove element accessor assertions (tested already above)
- Add roundtrip encoding assertion
33edaf935d fix: check overflow for push_int with push_int_unchecked (Chris Hyunhum Cho)
876146154b refactor: use push_lock_time instead of push_int (Chris Hyunhum Cho)
Pull request description:
Fix the issue https://github.com/rust-bitcoin/rust-bitcoin/issues/1530. In the discussion of https://github.com/rust-bitcoin/rust-bitcoin/issues/1530, the suggested solution is to implement `ScriptInt` type to embrace the various type of integer(`i32, u32, i64, u64, i128, u128, isize, usize...`) to support both script number and locktime number.
However, as `push_locktime` and `push_sequence` implemented, there’s no need to support `u32` of lock time for `push_int` anymore. Therefore, I’ve just changed the type of parameter to `i32`, and only check if it’s `i32::MIN`(which overflows 4 bytes sign-magnitude integer).
~I also added push_uint method to use internally for `push_locktime` and `push_sequence`, which have a dependency on `push_int` method.~
UPDATE: also add `push_int_unchecked` for those who want to push the integer out of range(and helper for `push_locktime` and `push_sequence`, which has the same functionality of former `push_int`.
ACKs for top commit:
tcharding:
ACK 33edaf935d
Tree-SHA512: 89b02bd3faf1e0a1ed530b7210250f0db33886d2acd553d07761f4aef0bb6388b22ddc06a88de05acfe465305db4cf34822fb6547576aae2aa224b4d0045fa07
The current unit test is incorrect, the indices field of a witness with
a single element starts at 1 because 0 is encode as a single
byte (compact encoded integer).
Fix the debug test and add a test that pushes an empty slice.
Recently we removed the `all_zeros` function from `OutPoint` in favour
of a more meaningfully named associated const. We can do the same for
`BlockHash`, the all zeros has is used for the previous blockhash of the
genesis block, add a const named as such.
In test code where we use the `all_zeros` function, just use the more
explicit form `from_byte_array([0; 32])`.
Currently we provide `Default` implementations for a couple of types in
the `transaction` module, the values returned are meaningless and it
seems these impls were added to make writing test code easier. In
hindsight this was the wrong thing to do.
Break the API and remove the `Default` implementations for `OutPoint`
and `TxIn`.
Add an associated const `TxIn::EMPTY_COINBASE` that is, as the name
suggests, an empty transaction input with the prevout set to all
zeros as for the coinbase transaction.