At wallet loading, we rely on chain state querying to retrieve
height of txn, to do so we ensure that lock order is respected
between cs_main and cs_wallet.
If wallet loaded is the wallet-tool one, all wallet txn will
show up with a height of zero. It doesn't matter as confirmation
height is not used by wallet-tool.
Reorder arguments and document Confirmation calls to avoid
ambiguity.
Fixes nits left from #16624
To do so we update CValidationInterface::BlockDisconnect to take a
CBlockIndex pointing to the block being disconnected.
This new parameter will be use in the following commit to establish
wallet height.
1a8f0d5a74 [tools] update nNextInvSend to use mockable time (Amiti Uttarwar)
4de630354f [tools] add PoissonNextSend method that returns mockable time (Amiti Uttarwar)
Pull request description:
Introduce a Poisson helper method that wraps the existing method to return `std::chrono::duration` type, which is mockable.
Needed for https://github.com/bitcoin/bitcoin/pull/16698.
ACKs for top commit:
ajtowns:
ACK 1a8f0d5a74
MarcoFalke:
re-ACK 1a8f0d5a74
naumenkogs:
ACK 1a8f0d5, and let's merge it and come back to it later.
Tree-SHA512: 7e2325d7c55fc0b4357cb86b83e0c218ba269f678c1786342d8bc380bfd9696373bc24ff124b9ff17a6e761c62b2b44ff5247c3911e2afdc7cc5c20417e8290b
3fe1aba601 depends: move README.md Android instructions to a separate section (Igor Cota)
aa9b84acee depends: update README.md with working Android targets and API levels (Igor Cota)
Pull request description:
Per @Sjors comments in https://github.com/bitcoin/bitcoin/pull/16110#pullrequestreview-310821810
ACKs for top commit:
Sjors:
ACK 3fe1aba
Tree-SHA512: 7a2e676070d51c7a4291b0d4b638f52321c08cc6ebe2bd2c02ba62f6cc3dd8a73227df4693c6ce9201863eb0bf26e0133805347b9016cb0f9a389a49cc9492aa
4671fc3d9e Expand on wallet_balance.py comment from https://github.com/bitcoin/bitcoin/pull/16766\#issuecomment-527563982 (Jeremy Rubin)
91f3073f08 Update release notes to mention changes to IsTrusted and impact on wallet (Jeremy Rubin)
8f174ef112 Systematize style of IsTrusted single line if (Jeremy Rubin)
b49dcbedf7 update variable naming conventions for IsTrusted (Jeremy Rubin)
5ffe0d1449 Update comment in test/functional/wallet_balance.py (Jeremy Rubin)
a550c58267 Update wallet_balance.py test to reflect new behavior (Jeremy Rubin)
5dd7da4ccd Reuse trustedParents in looped calls to IsTrusted (Jeremy Rubin)
595f09d6de Cache tx Trust per-call to avoid DoS (Jeremy Rubin)
dce032ce29 Make IsTrusted scan parents recursively (Jeremy Rubin)
Pull request description:
This slightly modifies the behavior of IsTrusted to recursively check the parents of a transaction. Otherwise, it's possible that a parent is not IsTrusted but a child is. If a parent is not trusted, then a child should not be either.
This recursive scan can be a little expensive, so ~it might be beneficial to have a way of caching IsTrusted state, but this is a little complex because various conditions can change between calls to IsTrusted (e.g., re-org).~ I added a cache which works per call/across calls, but does not store the results semi-permanently. Which reduces DoS risk of this change. There is no risk of untrusted parents causing a resource exploitation, as we immediately return once that is detected.
This is a change that came up as a bug-fix esque change while working on OP_SECURETHEBAG. You can see the branch where this change is important here: https://github.com/bitcoin/bitcoin/compare/master...JeremyRubin:stb-with-rpc?expand=1. Essentially, without this change, we can be tricked into accepting an OP_SECURETHEBAG output because we don't properly check the parents. As this was a change which, on its own, was not dependent on OP_SECURETHEBAG, I broke it out as I felt the change stands on its own by fixing a long standing wallet bug.
The test wallet_balance.py has been corrected to meet the new behavior. The below comment, reproduced, explains what the issue is and the edge cases that can arise before this change.
# Before `test_balance()`, we have had two nodes with a balance of 50
# each and then we:
#
# 1) Sent 40 from node A to node B with fee 0.01
# 2) Sent 60 from node B to node A with fee 0.01
#
# Then we check the balances:
#
# 1) As is
# 2) With transaction 2 from above with 2x the fee
#
# Prior to #16766, in this situation, the node would immediately report
# a balance of 30 on node B as unconfirmed and trusted.
#
# After #16766, we show that balance as unconfirmed.
#
# The balance is indeed "trusted" and "confirmed" insofar as removing
# the mempool transactions would return at least that much money. But
# the algorithm after #16766 marks it as unconfirmed because the 'taint'
# tracking of transaction trust for summing balances doesn't consider
# which inputs belong to a user. In this case, the change output in
# question could be "destroyed" by replace the 1st transaction above.
#
# The post #16766 behavior is correct; we shouldn't be treating those
# funds as confirmed. If you want to rely on that specific UTXO existing
# which has given you that balance, you cannot, as a third party
# spending the other input would destroy that unconfirmed.
#
# For example, if the test transactions were:
#
# 1) Sent 40 from node A to node B with fee 0.01
# 2) Sent 10 from node B to node A with fee 0.01
#
# Then our node would report a confirmed balance of 40 + 50 - 10 = 80
# BTC, which is more than would be available if transaction 1 were
# replaced.
The release notes have been updated to note the new behavior.
ACKs for top commit:
ariard:
Code Review ACK 4671fc3, maybe extend DoS protection in a follow-up PR.
fjahr:
Code review ACK 4671fc3d9e
ryanofsky:
Code review ACK 4671fc3d9e. Changes since last review: 2 new commits adding suggested release note and python test comment, also a clean rebase with no changes to the earlier commits. The PR description is more comprehensive now, too. Looks good!
promag:
Code review ACK 4671fc3d9e.
Tree-SHA512: 6b183ff425304fef49724290053514cb2770f4a2350dcb83660ef24af5c54f7c4c2c345b0f62bba60eb2d2f70625ee61a7fab76a7f491bb5a84be5c4cc86b92f
436ad43643 Fix issue with conflicted mempool tx in listsinceblock (Adam Jonas)
Pull request description:
Closes#8752 by bringing back abandoned #10470.
This now checks that returned transactions are not conflicting with any transactions that are filtered out by the given blockhash and add a functional test to prevent this in the future.
For more context, #8757 was closed in favor of #10470.
ACKs for top commit:
instagibbs:
utACK 436ad43643
kallewoof:
utACK 436ad43643
jonatack:
I'm not qualifed to give an ACK here but 436ad43643 appears reasonable. Built/ran tests/verified that this test fails without the change in rpcwallet.cpp:
Tree-SHA512: 63d75cd3d3f19fc84dc38899b200c96179b82b24db263cd0116ee5b715265be647157855c2e35912d2fbc49c7b37db9375d6aab0ac672f0f09bece8431de5ea9
19139ee034 Add documentation for test_shell submodule (JamesC)
f5112369cf Add TestShell class (James Chiang)
5155602a63 Move argparse() to init() (JamesC)
2ab01462f4 Move assert num_nodes is set into main() (JamesC)
614c645643 Clear TestNode objects after shutdown (JamesC)
6f40820757 Add closing and flushing of logging handlers (JamesC)
6b71241291 Refactor TestFramework main() into setup/shutdown (JamesC)
ede8b7608e Remove network_event_loop instance in close() (JamesC)
Pull request description:
This PR refactors BitcoinTestFramework to encapsulate setup and shutdown logic into dedicated methods, and adds a ~~TestWrapper~~ TestShell child class. This wrapper allows the underlying BitcoinTestFramework to run _between user inputs_ in a REPL environment, such as a Jupyter notebook or any interactive Python3 interpreter.
The ~~TestWrapper~~ TestShell is motivated by the opportunity to expose the test-framework as a prototyping and educational toolkit. Examples of code prototypes enabled by ~~TestWrapper~~ TestShell can be found in the Optech [Taproot/Schnorr](https://github.com/bitcoinops/taproot-workshop) workshop repository.
Usage example:
```
>>> import sys
>>> sys.path.insert(0, "/path/to/bitcoin/test/functional")
```
```
>>> from test_framework.test_wrapper import TestShell
>>> test = TestShell()
>>> test.setup(num_nodes=2)
20XX-XX-XXTXX:XX:XX.XXXXXXX TestFramework (INFO): Initializing test directory /path/to/bitcoin_func_test_XXXXXXX
```
```
>>> test.nodes[0].generate(101)
>>> test.nodes[0].getblockchaininfo()["blocks"]
101
```
```
>>> test.shutdown()
20XX-XX-XXTXX:XX:XX.XXXXXXX TestFramework (INFO): Stopping nodes
20XX-XX-XXTXX:XX:XX.XXXXXXX TestFramework (INFO): Cleaning up /path/to/bitcoin_func_test_XXXXXXX on exit
20XX-XX-XXTXX:XX:XX.XXXXXXX TestFramework (INFO): Tests successful
```
**Overview of changes to BitcoinTestFramework:**
- Code moved to `setup()/shutdown()` methods.
- Argument parsing logic encapsulated by `parse_args` method.
- Success state moved to `BitcoinTestFramework.success`.
_During Shutdown_
- `BitcoinTestFramework` logging handlers are flushed and removed.
- `BitcoinTestFrameowork.nodes` list is cleared.
- `NetworkThread.network_event_loop` is reset. (NetworkThread class).
**Behavioural changes:**
- Test parameters can now also be set when overriding BitcoinTestFramework.setup() in addition to overriding `set_test_params` method.
- Potential exceptions raised in BitcoinTestFramework.setup() will be handled in main().
**Added files:**
- ~~test_wrapper.py~~ `test_shell.py`
- ~~test-wrapper.md~~ `test-shell.md`
ACKs for top commit:
jamesob:
ACK 19139ee034
jonatack:
ACK 19139ee034
jnewbery:
Rather than invalidate the three ACKs for a minor nit, can you force push back to 19139ee034 please? I think this PR was ready to merge before your last force push.
jachiang:
> Rather than invalidate the three ACKs for a minor nit, can you force push back to [19139ee](19139ee034) please? I think this PR was ready to merge before your last force push.
jnewbery:
ACK 19139ee034
Tree-SHA512: 0c24f405f295a8580a9c8f1b9e0182b5d753eb08cc331424616dd50a062fb773d3719db4d08943365b1f42ccb965cc363b4bcc5beae27ac90b3460b349ed46b2
fa07b8beb5 test: Reset global args between test suites (MarcoFalke)
Pull request description:
Ideally there wouldn't be any globals in Bitcoin Core. However, as we still have globals, they need to be reset between runs of test cases. One way to do this is to run each suite in a different process. `make check` does that. However, `./src/test/test_bitcoin` when run manually or on appveyor is a single process, where all globals are preserved between test cases.
This leads to hard to debug issues such as https://github.com/bitcoin/bitcoin/pull/15845#pullrequestreview-310852164.
Fix that by resetting the global arg for each test suite. Note that this wont reset the arg between test cases, as the constructor/destructor is not called for them.
Addendum: This is not a general fix, only for `-segwitheight`. I don't know if clearing all args can be done with today's argsmanager. Nor do I know if it makes sense. Maybe we want datadir set to a temp path to not risk accidentally corrupting the default data dir?
ACKs for top commit:
laanwj:
ACK fa07b8beb5
practicalswift:
ACK fa07b8beb5
mzumsande:
ACK fa07b8beb5, I also tested that this fixes the issue in #15845.
Tree-SHA512: 1e30b06f0d2829144a61cc1bc9bdd6a694cbd911afff83dd3ad2a3f15b577fd30acdf9f1469f8cb724d0642ad5d297364fd5a8a2a9c8619a7a71fa9ae2837cdc
c98bd13e67 replace asserts in RPC code with CHECK_NONFATAL and add linter (Adam Jonas)
Pull request description:
- Replace instances of assert in /rpc files and rpcwallet with CHECK_NONFATAL(condition)
- Add a linter to prevent future usage of assert being used in RPC code
ref https://github.com/bitcoin/bitcoin/pull/17192
ACKs for top commit:
practicalswift:
ACK c98bd13e67 -- diff looks correct
Tree-SHA512: a16036b6bbcca73a5334665f66e17e1756377d582317568291da1d727fc9cf8c84bac9d9bd099534e1be315345336e5f7b66b93793135155f320dc5862a2d875
8d8e5a79d0 test: use default address type (bech32) for wallet_bumpfee tests (Sebastian Falbesoner)
Pull request description:
The use of native segwit addresses (pure p2wpkh instead of p2sh-p2wpkh) leads to smaller transaction sizes, needing adaption of some constants in the following test cases:
- `test_dust_to_fee()`: adaption of dust calculation (p2wpkh spend estimate of 67 is taken from `src/policy/policy.cpp:GetDustThreshold()`)
- `test_maxtxfee_fails()`: lowering `-maxtxfee` setting to trigger fail
Top commit has no ACKs.
Tree-SHA512: b4163700d56c11955f811bc5fe6edaf7aec69931d7db741c03b055fb518bb9825c031fb931c513b37a1968085cb8c2f263adf664b357aff8ee42795fd0f88d2d
b6d2183858 Minor refactoring to remove implied m_addr_relay_peer. (User)
a552e8477c added asserts to check m_addr_known when it's used (User)
090b75c14b p2p: Avoid allocating memory for addrKnown where we don't need it (User)
Pull request description:
We should allocate memory for addrKnown filter only for those peers which are expected to participate in address relay.
Currently, we do it for all peers (including SPV and block-relay-only), which results in extra RAM where it's not needed.
Upd:
In future, we would still allow SPVs to ask for addrs, so allocation still will be done by default.
However, they will be able to opt-out via [this proposal](https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2019-October/017428.html) and then we could save some more memory.
This PR still saves memory for block-relay-only peers immediately after merging.
Top commit has no ACKs.
Tree-SHA512: e84d93b2615556d466f5ca0e543580fde763911a3bfea3127c493ddfaba8f05c8605cb94ff795d165af542b594400995a2c51338185c298581408687e7812463
152b0a00d8 Refactor: Move nTimeFirstKey accesses out of CWallet (Andrew Chow)
7ef47b88e6 Refactor: Move GetKeypoolSize code out of CWallet (Andrew Chow)
089e17d45c Refactor: Move RewriteDB code out of CWallet (Andrew Chow)
0eac7088ab Refactor: Move SetupGeneration code out of CWallet (Andrew Chow)
f45d12b36c Refactor: Move HavePrivateKeys code out of CWallet::CreateWalletFromFile (Andrew Chow)
8b0d82bb42 Refactor: Move Upgrade code out of CWallet::CreateWalletFromFile (Andrew Chow)
46865ec958 Refactor: Move MarkUnusedAddresses code out of CWallet::AddToWalletIfInvolvingMe (Andrew Chow)
a18edd7b38 Refactor: Move GetMetadata code out of getaddressinfo (Andrew Chow)
9716bbe0f8 Refactor: Move LoadKey LegacyScriptPubKeyMan method definition (Andrew Chow)
67be6b9e21 Refactor: Move SetAddressBookWithDB call out of LegacyScriptPubKeyMan::ImportScriptPubKeys (Andrew Chow)
fc2867fdf5 refactor: Replace UnsetWalletFlagWithDB with UnsetBlankWalletFlag in ScriptPubKeyMan (Andrew Chow)
78e7cbc7ba Refactor: Remove UnsetWalletFlag call from LegacyScriptPubKeyMan::SetHDSeed (Andrew Chow)
0391aba52d Remove SetWalletFlag from WalletStorage (Andrew Chow)
4c5491f99c Refactor: Move SetWalletFlag out of LegacyScriptPubKeyMan::UpgradeKeyMetadata (Andrew Chow)
769acef857 Refactor: Move SetAddressBook call out of LegacyScriptPubKeyMan::GetNewDestination (Andrew Chow)
acedc5b823 Refactor: Add new ScriptPubKeyMan virtual methods (Andrew Chow)
533d8b364f Refactor: Declare LegacyScriptPubKeyMan methods as virtual (Andrew Chow)
b4cb18bce3 MOVEONLY: Reorder LegacyScriptPubKeyMan methods (Andrew Chow)
Pull request description:
Moves several more key management and metadata functions into LegacyScriptPubKeyMan from CWallet to further separate the two.
Note to reviewers: All of the `if (auto spk_man = walletInstance->m_spk_man.get()) {` blocks will be replaced with for loops in the next PR so you may see some things in those blocks that don't necessarily make sense with an `if` but will with a `for`.
ACKs for top commit:
laanwj:
code review ACK 152b0a00d8
Sjors:
re-ACK 152b0a00d8
promag:
Code review ACK 152b0a00d8.
Tree-SHA512: ff9872a3ef818922166cb15d72363004ec184e1015a3928a66091bddf48995423602ccd7e55b814de85d25ad7c69058280b1fde2e633570c680dc7d6084b3122
fa8919889f bench: Remove redundant copy constructor in mempool_stress (MarcoFalke)
29f8434368 refactor: Remove redundant PSBT copy constructor (Hennadii Stepanov)
Pull request description:
I fail to see why people add these copy constructors manually without explanation, when the compiler can generate them at least as good automatically with less code.
ACKs for top commit:
promag:
ACK fa8919889f.
hebasto:
ACK fa8919889f, nit s/constructor/operator/ in commit fa8919889f message, as @promag [mentioned](https://github.com/bitcoin/bitcoin/pull/17349#discussion_r341776389) above.
jonatack:
ACK fa8919889f
Tree-SHA512: ce024fdb894328f41037420b881169b8b1b48c87fbae5f432edf371a35c82e77e21468ef97cda6f54d34f1cf9bb010235d62904bb0669793457ed1c3b2a89723
facc0da63a travis: Run unit and functional tests on native arm (MarcoFalke)
fafa064d2a ci: Remove ccache requirement on the host (MarcoFalke)
Pull request description:
This keeps the cross-compilation to make it easy to run the ci on non-arm hardware. To run this locally in qemu-user as it used to be, just `export QEMU_USER_CMD="qemu-arm -L /usr/arm-linux-gnueabihf/"`.
ACKs for top commit:
laanwj:
LGTM ACK facc0da63a
practicalswift:
ACK facc0da63a -- diff looks correct and Travis seems happy
Tree-SHA512: 0dc1bc82eb93e2bd8b159e044f20fe3055f8cdfd73aaa238bd2e178397582144dfc0c6a87bd8270115dafea1a623e642bde5d5f30254f94140f1a2cdb12fc2da
fa0a731d00 test: Add RegTestingSetup to setup_common (MarcoFalke)
fa54b3e248 test: move-only ComputeFilter to src/test/lib/blockfilter (MarcoFalke)
Pull request description:
The default chain for `TestingSetup` is the main chain. However, any test that wants to mine blocks on demand needs to switch to regtest. This is done manually and in-line right now.
Fix that by creating an explicit `RegTestingSetup` and use it where appropriate.
Also, add a move-only commit to move `ComputeFilter` into the newly created unit test library.
Both commits are part of #15845, but split up because they are useful on their own.
ACKs for top commit:
practicalswift:
ACK fa0a731d00 -- diff looks correct
Tree-SHA512: 02b9765580b355ed8d1be555f8ae11fa6e3d575f5cb177bbdda0319378837e29de5555c126c477dc8a1e8a5be47335afdcff152cf2dea2fbdd1a988ddde3689b
ac831339cb doc: Fix some misspellings (randymcmillan)
Pull request description:
Here is a more thorough lint-spelling update.
This PR takes care of easy to fix spelling errors to clean up the linting stages.
There are misspellings coded into the functional tests.
That is a whole separate job within itself.
ACKs for top commit:
practicalswift:
ACK ac831339cb -- diff looks correct
Tree-SHA512: d8fad83fed083715655f148263ddeffc6752c8007d568fcf3dc2c418ccd5db70089ce3ccfd3994fcbd78043171402eb9cca5bdd5125287e22c42ea305aaa6e9d
f9af3ced1c Android: add all arch support (Block Mechanic)
d419ca7e32 depends: export dynamic JNI symbols from static qtforandroid.a (Igor Cota)
ed30684d03 Qt: patch androidjnimain.cpp to make sure JNI is initialised when statically compiled (Igor Cota)
e4c319e8a1 builds: remove superfluous config_opts_aarch64_android (Igor Cota)
24ffef0c27 Patch libevent when building for Android (fix arc4random_addrandom) (Igor Cota)
f1e40b3e71 Update bitcoin_qt.m4 (BlockMechanic)
b4057d8261 Define TARGET_OS when host is android (Igor Cota)
80b475f159 Fix Android zlib cross compilation issue (https://stackoverflow.com/questions/21396988/zlib-build-not-configuring-properly-with-cross-compiler-ignores-ar) (Igor Cota)
45f8219015 Add full Android build example command and instructions on getting SDK/NDK (Igor Cota)
b68f2a68c2 Add config opts and patch for aarch64_android build of Qt (Igor Cota)
9c4cb0166e Add ranlib to android.mk hosts file (fix OSX Android NDK build) (Igor Cota)
c2a749c9c1 Add example Android host-platform-triplet and options (Igor Cota)
0b0cff3c61 Add support for building Android dependencies (Igor Cota)
Pull request description:
This allows one to build the dependencies with the Android SDK and goes towards fixing #11844. It has been tested to work with:
`make HOST=aarch64-linux-android ANDROID_API_LEVEL=28 ANDROID_TOOLCHAIN_BIN=/home/user/Android/Sdk/ndk-bundle/toolchains/llvm/prebuilt/linux-x86_64/bin NO_QT=1 NO_WALLET=1`
ACKs for top commit:
Sjors:
ACK f9af3ce. I'm OK with merging and then improving later.
Tree-SHA512: cb805115ebe5c9e33db2bf3eab8628808fe3f50052053d8877d8b8e4406d6fea1ed9e5c4dff85d777fb99c81be6ffb9d95a0e6d32344e728e5e0da6c653e2ce7
f44abe4bed refactor: Remove addrdb.h dependency from node.h (Hennadii Stepanov)
Pull request description:
`node.h` includes `addrdb.h` just for the sake of `banmap_t` type.
This PR makes dependencies simpler and explicit.
~Also needless `typedef` has been removed from `enum BanReason`.~
ACKs for top commit:
laanwj:
ACK f44abe4bed
practicalswift:
ACK f44abe4bed
Tree-SHA512: 33a1be20e5c629daf4a61ebbf93ea6494b9256887cebd4974de4782f6d324404b6cc84909533d9502b2cc19902083f1f9307d4fb7231e67db5b412b842d13072
A BitcoinTestFramework child class which can be imported by an external user or
project. TestShell.setup() initiates an underlying BitcoinTestFramework object
with bitcoind subprocesses, rpc interfaces and test logging.
TestShell.shutdown() safely tears down the BitcoinTestFramework object.
This ensures TestFramework default parameters are set before setup is called. A
child class will therefore have access to defaults when overriding setup.
In order for BitcoinTestFramework to correctly restart after shutdown, the
previous logging handlers need to be removed, or else logging will continue in
the previous temp directory. "Flush" ensures buffers are emptied, and "close"
ensures file handler close logging file.
Setup and shutdown code now moved into dedicated methods. Test "success" is
added as a BitcoinTestFramework member, which can be accessed outside of main.
Argument parsing also moved into separate method and called from main.
The asyncio.new_event_loop() instance is now removed from the NetworkThread
class during shutdown. This enables a NetworkThread instance to be restarted
after being closed. The current NetworkThread class guards against an existing
new_event_loop during initialization.
3ed8e3d079 doc: Remove explicit network name references (Fabian Jahr)
d6e493f0c2 wallet: Remove left-over BIP70 comment (Fabian Jahr)
Pull request description:
A small follow-up to #17165 which removed BIP70 support.
1. Removes one leftover mention of BIP70 in a comment.
2. Removes BIP70 reference in comments on network/chain name strings. These can be removed as they are not really helpful and also incorrect: BIP70 only defines "main" and "test" but not "regtest". If/When signet gets merged we will add another name to the list that is not defined in BIP70. Mostly there is also an exhaustive list of the options included in the comment anyway.
If we would like to keep an identifier for this naming scheme, I would suggest switching to something more generic, like 'short chain name'. Happy to implement that if that is preferred. Alternatively, we could add a reference to `CBaseChainParams`. That would also mean we don't have to change these lines again for signet.
ACKs for top commit:
MarcoFalke:
ACK 3ed8e3d079
Tree-SHA512: 9a7c0b9cacbb67bd31a089ffdc6f1ebc7f336493e2c8266eb697da34dce2b505a431d5639a3e4fc34f9287361343e861b55dc2662e0a1d2095cc1046db77d6ee
a35b6824f3 Add assertion to randrange that input is not 0 (Jeremy Rubin)
Pull request description:
From the comment in randrange, their is an implicit argument that randrange cannot accept an argument of 0. If the argument is 0, then we have to return {}, which is not possible in a uint64_t.
The current code takes a very interesting approach, which is to return [0..std::numeric_limits<uint64_t>]. This can cause all sorts of fun problems, like allocating a lot of memory, accessing random memory (maybe with your private keys), and crashing the computer entirely.
This gives us three choices of how to make it "safe":
1) return Optional<uint64_t>
2) Change the return type to [0..range]
3) Return 0 if 0
4) Assert(range)
So which solution is best?
1) seems a bit overkill, as it makes any code using randrange worse.
2) Changing the return type as in 2 could be acceptable, but it imposes the potential overflow checking on the caller (which is what we want).
3) An interesting option -- effective makes the return type in {0} U [0..range]. But this is a bad choice, because it leads to code like `vec[randrange(vec.size())]`, which is incorrect for an empty vector. Null set should mean null set.
4) Assert(range) stands out as the best mitigation for now, with perhaps a future change to solution 2. It prevents the error from propagating at the earliest possible time, so the program crashes cleanly rather than by freezing the computer or accessing random memory.
ACKs for top commit:
instagibbs:
Seems reasonable for now, ACK a35b6824f3
laanwj:
ACK a35b6824f3
promag:
ACK a35b6824f3.
Tree-SHA512: 8fc626cde4b04b918100cb7af28753f25ec697bd077ce0e0c640be0357626322aeea233e3c8fd964ba1564b0fda830b7f5188310ebbb119c113513a4b89952dc
