9b8dcb25b57ad31b77c9f37d9a1f5b07dc6378b4 [net processing] Rename PoissonNextSendInbound to NextInvToInbounds (John Newbery)
ea99f5d01e56ab0192d211da1034ffb299876937 [net processing] Move PoissonNextSendInbound to PeerManager (John Newbery)
bb060746df22c956b8f44e5b8cd1ae4ed73faddc scripted-diff: replace PoissonNextSend with GetExponentialRand (John Newbery)
03cfa1b6035dbcf6a414f9bc432bd9e612801ebb [refactor] Use uint64_t and std namespace in PoissonNextSend (John Newbery)
9e64d69bf74c8a381fb59841519cc3736bce14d4 [move] Move PoissonNextSend to src/random and update comment (John Newbery)
Pull request description:
`PoissonNextSend` and `PoissonNextSendInbound` are used in the p2p code to obfuscate various regularly occurring processes, in order to make it harder for others to get timing-based information deterministically.
The naming of these functions has been confusing to several people (including myself, see also #23347) because the resulting random timestamps don't follow a Poisson distribution but an exponential distribution (related to events in a Poisson process, hence the name). This PR
- moves `PoissonNextSend()` out of `net` to `random` and renames it to `GetExponentialRand()`
- moves `PoissonNextSendInbound()` out of `CConnman` to `PeerManager` and renames it to `NextInvToInbounds()`
- adds documentation for these functions
This is work by jnewbery - due to him being less active currently, I opened the PR and will address feedback.
ACKs for top commit:
jnewbery:
ACK 9b8dcb25b5
hebasto:
ACK 9b8dcb25b57ad31b77c9f37d9a1f5b07dc6378b4, I have reviewed the code and it looks OK, I agree it can be merged.
theStack:
ACK 9b8dcb25b57ad31b77c9f37d9a1f5b07dc6378b4 📊
Tree-SHA512: 85c366c994e7147f9981fe863fb9838502643fa61ffd32d55a43feef96a38b79a5daa2c4d38ce01074897cc95fa40c76779816edad53f5265b81b05c3a1f4f50
36012ef143917f97179d3ba6599ef36a26a9a014 qa: test descriptors with mixed xpubs and const pubkeys (Antoine Poinsot)
Pull request description:
Writing unit tests for Miniscript descriptors i noticed that `test/descriptor_tests`'s `DoCheck()` assumes that a descriptor would either contain only extended keys or only const pubkeys: if it detects an xpub in the descriptor it would assert the number of cached keys is equal to the number of keys in the descriptor, which does not hold if the descriptor also contains const (raw?) public keys since we only cache parent xpubs.
ACKs for top commit:
achow101:
ACK 36012ef143917f97179d3ba6599ef36a26a9a014
Tree-SHA512: 2ede67a6dff726bcad3e260f3deb25c9b77542ed1880eb4ad136730b741014ce950396c69c7027225de1ef27108d609bafd055188b88538ace0beb13c7e34b0b
5e7e4c9f6e57f5333bd17a20b0c85a78d032998e refactor: replace RecursiveMutex g_maplocalhost_mutex with Mutex (w0xlt)
a7da1409bc9f614009f76c1bfc55f029ff1265e4 scripted-diff: rename cs_mapLocalHost -> g_maplocalhost_mutex (w0xlt)
Pull request description:
This PR is related to #19303 and gets rid of the `RecursiveMutex cs_mapLocalHost`.
ACKs for top commit:
shaavan:
ACK 5e7e4c9f6e57f5333bd17a20b0c85a78d032998e
theStack:
ACK 5e7e4c9f6e57f5333bd17a20b0c85a78d032998e
hebasto:
ACK 5e7e4c9f6e57f5333bd17a20b0c85a78d032998e, I have reviewed the code and it looks OK, I agree it can be merged.
Tree-SHA512: 961171e346fe385e16db9830115a8096f4ca2499bbea11a08c02ca808638dfb63c434ab9d66392c71e85be6352c8a2b6a0054b5a61aaabd28d71581fed5beae7
e2ab9f83f8655bf09ea392beeee36b2bbe29769b build: disable external signer on Windows (fanquake)
Pull request description:
This change explicitly disables support for external signing when targeting Windows and OpenBSD. The driver for this is that Boost Process uses boost::filesystem internally, when targeting Windows, which gets in the way of removing our usage of it (#20744). While we could adjust #20744 to still link against the Boost libs when building for Windows, that would be disappointing, as we wouldn't have cleanly removed the Boost usage we're trying too (including the build infrastructure), and, we'd be in a position where we would be building releases differently depending on the platform, which is something I want to avoid.
After discussion with Sjors, Achow and Hebasto, this seemed like a reasonable step to move #20744 forward (as-is). Note that support for external signing ([while already being experimental](https://github.com/bitcoin/bitcoin/blob/master/doc/external-signer.md#example-usage)), could be considered even more experimental on Windows. Also, oddly, we have external-signing [explicitly disabled in our Windows (cross-compile) CI](807169e10b/ci/test/00_setup_env_win64.sh (L16)), it's not clear why this is the case, as, if it's a feature being built into releases, it should be being built and tested in the CI which is most-like the release process.
There is an [issue open upstream](https://github.com/boostorg/process/issues/207), in regards to migrating Boost Process to std::filesystem, or having an option to use it. However there hasn't been much discussion since it was opened ~9 months ago. There is another related issue here: https://github.com/klemens-morgenstern/boost-process/issues/164.
Resolves#24036.
ACKs for top commit:
Sjors:
utACK e2ab9f8
achow101:
ACK e2ab9f83f8655bf09ea392beeee36b2bbe29769b
kallewoof:
utACK e2ab9f83f8655bf09ea392beeee36b2bbe29769b
hebasto:
ACK e2ab9f83f8655bf09ea392beeee36b2bbe29769b, tested on Linux Mint 20.2 (x86_64).
Tree-SHA512: 36fcfc0e1a008a8271dc76b8e12e93d3e1d1e528bf668e95a559e9f6fd7d5f031bd7a6a6bc8b9fa9d057b2cd56f9ec8838c7f74e87899bf9a6aeb787afbd112c
dc5d6b0d4793ca978f71f69ef7d6b818794676c2 fs: Make compatible with boost 1.78 (Andrew Chow)
Pull request description:
Boost 1.78 removed `operator+` in a way that breaks our usage of it in a subclass. A [proposed workaround](https://github.com/boostorg/filesystem/issues/223#issuecomment-1000230207) for this is to cast the argument to `boost::filesystem::path`, and this is backwards compatible with older versions of boost.
Additionally, it appears that `fs::canonical` no longer removes trailing slashes. This was causing a test to fail. The solution is to explicitly remove the trailing separator in the one place that `fs::canonical` is used.
Lastly, `fs::create_directories` now has an error message saying `create_directories` instead of `create_directory`. This caused wallet_multiwallet.py to fail. The error message check has been updated to be able accept either string.
Fixes#23846
ACKs for top commit:
ryanofsky:
Code review ACK dc5d6b0d4793ca978f71f69ef7d6b818794676c2
vincenzopalazzo:
ACK dc5d6b0d47
Tree-SHA512: d4d8e7b49b8dfbf0ced9bfe9a2b3827841227fc755fc799f19159076b0ccf882432cc8b6ad93cdeda98fb58b942b9ba50a9e0a6b4f6b1e0097e80f1074ae5682
e177fcab3831b6d259da5164cabedcc9e78f6957 Replace `struct update_lock_points` with lambda (glozow)
c7cd98c7176800a51e6a6b3634a26b508aa33ff2 document and clean up MaybeUpdateMempoolForReorg (glozow)
Pull request description:
followup to #23683, addressing https://github.com/bitcoin/bitcoin/pull/23683#issuecomment-989741186
ACKs for top commit:
hebasto:
ACK e177fcab3831b6d259da5164cabedcc9e78f6957, I have reviewed the code and it looks OK, I agree it can be merged.
instagibbs:
ACK e177fcab3831b6d259da5164cabedcc9e78f6957
MarcoFalke:
Approach ACK e177fcab3831b6d259da5164cabedcc9e78f6957 😶
Tree-SHA512: 8c2709dd5cab73cde41f3e5655d5f237bacfb341f78eac026169be579528695ca628c8777b7d89760d8677a4e6786913293681cfe16ab702b30c909703e1824c
-BEGIN VERIFY SCRIPT-
s() { sed -i 's/cs_mapLocalHost/g_maplocalhost_mutex/g' $1; }
s src/net.cpp
s src/net.h
s src/rpc/net.cpp
s src/test/net_tests.cpp
-END VERIFY SCRIPT-
No behavior change.
This code was introduced in 5add7a7 before we required C++11, which is
why the struct was needed. As we are now using more modern C++ and this
is the only place where lockpoints are updated for mempool entries, it
is more idiomatic to call `modify` with a lambda.
Co-authored-by: Hennadii Stepanov <32963518+hebasto@users.noreply.github.com>
7f122a4188af7130be9251611e41136a17c814f1 fuzz: non-addrman fuzz tests: override-able check ratio (Vasil Dimov)
3bd83e273d104e9474af8f1bdf4f969163e33ade fuzz: addrman fuzz tests: override-able check ratio (Vasil Dimov)
46b0fe78298c8f416a91dec9d4e0f3f4cb1e68b0 test: non-addrman unit tests: override-able check ratio (Vasil Dimov)
81e4d54d3a95f7bffeb353217a6c32eb2aca8b5c test: addrman unit tests: override-able check ratio (Vasil Dimov)
6dff6214be768a3fab6d5201daf5ef6071764746 bench: put addrman check ratio in a variable (Vasil Dimov)
6f7c7567c578b5a41f8e90ce4491e40f7faeaa56 fuzz: parse the command line arguments in fuzz tests (Vasil Dimov)
92a0f7e58d4b6323d21f1c45d4c20266c35df030 test: parse the command line arguments in unit tests (Vasil Dimov)
Pull request description:
Previously command line arguments passed to unit and fuzz tests would be ignored by the tests themselves. They would be used by the boost test framework (e.g. `--run_test="addrman_tests/*"`) or by the fuzzer (e.g. `-runs=1`). However both provide ways to pass down the extra arguments to the test itself. Use that, parse the arguments and make them available to the tests via `gArgs`.
This makes the tests more flexible as they can be run with any bitcoind config option specified on the command line.
When creating `AddrMan` objects in tests, use `-checkaddrman=` (if provided) instead of hardcoding the check ratio in many different places. See https://github.com/bitcoin/bitcoin/pull/20233#issuecomment-889813074 for further motivation for this.
ACKs for top commit:
mzumsande:
re-ACK 7f122a4188af7130be9251611e41136a17c814f1
josibake:
reACK 7f122a4188
Tree-SHA512: 3a05e61e4d70a0569bb67594bcce3aad8fdef63cdcc54e2823a3bc9f18679571985004412b6c332a210f67849bab32d8467b4115fbff8f5fac9834982e60dcf3
5574e6ed52d6effd3b7beff0f09b44449202a585 refactor: replace RecursiveMutex `m_callbacks_mutex` with Mutex (Sebastian Falbesoner)
3aa258109e3f3e0b1bfc4f811cbadfd6d516208c scripted-diff: rename `m_cs_callbacks_pending` -> `m_callbacks_mutex` (Sebastian Falbesoner)
Pull request description:
This PR is related to #19303 and gets rid of the RecursiveMutex `m_cs_callbacks_pending`. All of the critical sections (6 in total) only directly access the guarded elements, i.e. it is not possible that within one section another one is called, and we can use a regular Mutex:
807169e10b/src/scheduler.cpp (L138-L145)807169e10b/src/scheduler.cpp (L152-L160)807169e10b/src/scheduler.cpp (L169-L172)807169e10b/src/scheduler.cpp (L184-L187)807169e10b/src/scheduler.cpp (L197-L199)807169e10b/src/scheduler.cpp (L203-L206)
Also, it is renamed to adapt to the (unwritten) naming convention to use the `_mutex` suffix rather than the `cs_` prefix.
ACKs for top commit:
hebasto:
ACK 5574e6ed52d6effd3b7beff0f09b44449202a585, I have reviewed the code and it looks OK, I agree it can be merged.
w0xlt:
crACK 5574e6e
Tree-SHA512: ba4b151d956582f4c7183a1d51702b269158fc5e2902c51e6a242aaeb1c72cfcdf398f9ffa42e3072f5aba21a8c493086a5fe7c450c271322da69bd54c37ed1f
30927cb5306d01da2716786c2d9457c49ec49d0f refactor: replace RecursiveMutex `m_subver_mutex` with Mutex (Sebastian Falbesoner)
0639aba42ad8449fe43eb2aad0ffbe3390aabd37 scripted-diff: rename `cs_SubVer` -> `m_subver_mutex` (Sebastian Falbesoner)
Pull request description:
This PR is related to #19303 and gets rid of the RecursiveMutex `cs_SubVer`. Both of the critical sections only directly access the guarded variable, i.e. it is not possible that within one section another one is called, and we can use a regular Mutex.
ACKs for top commit:
hebasto:
ACK 30927cb5306d01da2716786c2d9457c49ec49d0f, I have reviewed the code and it looks OK, I agree it can be merged.
Tree-SHA512: 2faead792ea0b2f79f9f7fe99acde5cf2bfcd2f15c51fbb6cb1099d4f81276001a492f7d46a5139055f4366c2d58a36a8ba19f21d56df20e0ed93af3141dbe11
fa99e108e778b5169b3de2ce557af68f1fe0ac0b Fix implicit-integer-sign-change in arith_uint256 (MarcoFalke)
Pull request description:
This refactor doesn't change behaviour, but clarifies that the numbers being dealt with aren't supposed to be negative. This helps when reading the code and allows to remove a sanitizer suppression for the whole file.
ACKs for top commit:
PastaPastaPasta:
utACK fa99e108e778b5169b3de2ce557af68f1fe0ac0b
shaavan:
ACK fa99e108e778b5169b3de2ce557af68f1fe0ac0b
Tree-SHA512: f227e2fd22021e39f0445ec041f4a299d13477c23cef0fc06c53fb3313cbe550cec329336224a7e8775d9045b8009423052b394e83d42a1e40772085dfcdd471
fac22fd36b2d9f55dada31cc0da55520431b972a log: Remove GetAdjustedTime from IBD header progress estimation (MarcoFalke)
Pull request description:
This is a "refactor" that shouldn't change behaviour, because the two times are most likely equal. A minimum of 5 outbound peers are needed to adjust the time. And if the time is adjusted, it will be by at most 70 minutes (`DEFAULT_MAX_TIME_ADJUSTMENT`). Thus, the progress estimate should differ by at most 7 blocks.
ACKs for top commit:
laanwj:
Code review ACK fac22fd36b2d9f55dada31cc0da55520431b972a
vincenzopalazzo:
ACK fac22fd36b
Tree-SHA512: bf9f5eef66db0110dd268cf6dbfab64b9c11ba776924f5b386ceae3f2d005272cceb87ebcc96e0c8b854c051514854a2a5af39ae43bad008fac685b5aafaabd0
fa7238300c18938cdf627cacfc58d4b81602417f fuzz: Limit fuzzed time to years 2000-2100 (MarcoFalke)
Pull request description:
It doesn't make sense to fuzz times in the past, as Bitcoin Core will refuse to start in the past.
Fix that and also remove a sanitizer suppression, which would be hit in net_processing in `ProcessMessage`:
```cpp
if (addr.nTime <= 100000000 || addr.nTime > nNow + 10 * 60)
addr.nTime = nNow - 5 * 24 * 60 * 60; // <-- Here
```
This changes the format of fuzz inputs. Previously a time value was (de)serialized as 40 bytes, now it is 32 bytes.
ACKs for top commit:
mzumsande:
Code Review ACK fa7238300c18938cdf627cacfc58d4b81602417f
Tree-SHA512: ca6e7233beec2d9ef9fd481d8f1331942a4d2c8fe518b857629bebcc53a4f42ae123b994cf5d359384a0a8022098ff5a9c146600bc2593c6d88734e25bc240ad
In each of the critical sections, only the the guarded variable is
accessed, without any chance that within one section another one is
called. Hence, we can use an ordinary Mutex instead of RecursiveMutex.
In each of the critical sections, only the the guarded variables are
accessed, without any chance that within one section another one is
called. Hence, we can use an ordinary Mutex instead of RecursiveMutex.
c62d763fc313585d79ad833c9d729f6acf2652aa Necessary improvements to make configure work without libevent installed (Perlover)
091ccc38c2e589b649648cbcc99aca4802f98775 The evhttp_connection_get_peer function from libevent changes the type of the second parameter. Fixing the problem. (Perlover)
Pull request description:
The second parameter of evhttp_connection_get_peer in libevent already has type as `const char **`
The compilation of bitcoind with the fresh libevent occurs errors
Details: https://github.com/bitcoin/bitcoin/issues/23606
ACKs for top commit:
laanwj:
Code review ACK c62d763fc313585d79ad833c9d729f6acf2652aa
luke-jr:
tACK c62d763fc313585d79ad833c9d729f6acf2652aa
Tree-SHA512: d1c8062d90bd0d55c582dae2c3a7e5ee1b6c7ca872bf4aa7fe6f45a52ac4a8f59464215759d961f8efde0efbeeade31b08daf9387d7d50d7622baa1c06992d83
This distribution is used for more than just the next inv send, so make
the name more generic.
Also rename to "exponential" to avoid the confusion that this is a
poisson distribution.
-BEGIN VERIFY SCRIPT-
ren() { sed -i "s/\<$1\>/$2/g" $(git grep -l "$1" ./src) ; }
ren PoissonNextSend GetExponentialRand
ren "a poisson timer" "an exponential timer"
-END VERIFY SCRIPT-
b5c9bb5cb9f4a8db57b33ef7399310c7d6de5822 util: Restore GetIntArg saturating behavior (James O'Beirne)
Pull request description:
The new locale-independent atoi64 method introduced in #20452 parses large integer values higher than maximum representable value as 0 instead of the maximum value, which breaks backwards compatibility. This commit restores compatibility and adds test coverage for this case in terms of the related GetIntArg and strtoll functions.
Specifically, command line or bitcoin.conf integer values greater than `9223372036854775807` (`2**63-1`) used to be parsed as `9223372036854775807` before #20452. Then #20452 caused them to be parsed as `0`. And after this PR they will be parsed as `9223372036854775807` again.
This change is a stripped-down alternative version of #23841 by jamesob
ACKs for top commit:
jamesob:
Github ACK b5c9bb5cb9
vincenzopalazzo:
ACK b5c9bb5cb9
MarcoFalke:
review ACK b5c9bb5cb9f4a8db57b33ef7399310c7d6de5822 🌘
Tree-SHA512: 4e8abdbabf3cf4713cf5a7c5169539159f359ab4109a4e7e644cc2e9b2b0c3c532fad9f6b772daf015e1c5340ce59280cd9a41f2730afda6099cbf636b7d23ae
3c4f5d2a2024a71523a2e43e8144cdb0818dee6f scripted-diff: Rename functions to drop mention of boost (Hennadii Stepanov)
Pull request description:
Nothing specific to Boost is in `GUIUtil::qstringToBoostPath` and `GUIUtil::boostPathToQString` functions.
Related to bitcoin/bitcoin#20744.
ACKs for top commit:
laanwj:
Concept and code review ACK 3c4f5d2a2024a71523a2e43e8144cdb0818dee6f
promag:
Code review ACK 3c4f5d2a2024a71523a2e43e8144cdb0818dee6f 👋
Tree-SHA512: 0c8790979783a067811f7699b4ce4c204f6e0818d5f32986ec24b2c71583b4496d7a0e0c0361dd77c7e641a75d983fee35cd51ef722bbca9a5f13194efb3b4c0
The new locale-independent atoi64 method introduced in #20452 parses
large integer values higher than maximum representable value as 0
instead of the maximum value, which breaks backwards compatibility.
This commit restores compatibility and adds test coverage for this case
in terms of the related GetIntArg and strtoll functions.
Co-authored-by: Ryan Ofsky <ryan@ofsky.org>
Make it possible to override from the command line (without recompiling)
the addrman check ratio in non-addrman fuzz tests (connman and
deserialize) instead of hardcoding it to 0:
```
FUZZ=connman ./src/test/fuzz/fuzz --checkaddrman=5
```
Make it possible to override from the command line (without recompiling)
the addrman check ratio in addrman fuzz tests instead of hardcoding it
to 0:
```
FUZZ=addrman ./src/test/fuzz/fuzz --checkaddrman=5
```
Make it possible to override from the command line (without recompiling)
the addrman check ratio in the common `TestingSetup::m_node::addrman`
(used by all unit tests) instead of hardcoding it to 0:
```
test_bitcoin --run_test="transaction_tests/tx_valid" -- -checkaddrman=1
```
In addrman unit tests, make it possible to override the check ratio from
the command line, without recompiling:
```
test_bitcoin --run_test="addrman_tests/*" -- -checkaddrman=1
```
Also, make the arguments of the constructor of `AddrManTest` the
same as the arguments of `AddrMan`.
Retrieve the command line arguments from the fuzzer and save them for
later retrieval by `BasicTestingSetup` so that we gain extra flexibility
of passing any config options on the test command line, e.g.:
```
FUZZ=addrman ./src/test/fuzz/fuzz --checkaddrman=5
```
A fuzz test should call `MakeNoLogFileContext<>()` in its initialize
function in order to invoke the constructor of `BasicTestingSetup`,
which sets `gArgs`.
Retrieve the command line arguments from boost and pass them to
`BasicTestingSetup` so that we gain extra flexibility of passing any
config options on the test command line, e.g.:
```
test_bitcoin -- -printtoconsole=1 -checkaddrman=5
```
BlockManager is a large data structure, and cs_main is not required to
take its address or access every part of it. Individual BlockManager
fields and methods which do require cs_main like m_block_index and
LookupBlockIndex are already annotated separately, and these other
annotations describe locking requirements more accurately and do a
better job enforcing thread safety.
Since cs_main is not needed to access the address of the m_block object,
this commit drops cs_main LOCK calls which were added pointlessly to
satisfy this annotation in the past.
Co-authored-by: Carl Dong <contact@carldong.me>
e5b6aef61221b621ad77b5f075a16897e08835bf Move CBlockFileInfo::ToString method where class is declared (Russell Yanofsky)
f7086fd8ff084ab0dd656d75b7485e59263bdfd8 Add src/wallet/* code to wallet:: namespace (Russell Yanofsky)
90fc8b089d591cabff60ee829a33f96c37fd27ba Add src/node/* code to node:: namespace (Russell Yanofsky)
Pull request description:
There are no code changes, this is just adding `namespace` and `using` declarations and `node::` or `wallet::` qualifiers in some places.
Motivations for this change are:
- To make it easier to see when node and wallet code is being accessed places where it shouldn't be. For example if GUI code is accessing node and wallet internals or if wallet and node code are referencing each other.
- To make source code organization clearer ([#15732](https://github.com/bitcoin/bitcoin/issues/15732)), being able to know that `wallet::` code is in `src/wallet/`, `node::` code is in `src/node/`, `init::` code is in `src/init/`, `util::` code is in `src/util/`, etc.
Reviewing with `git log -p -n1 -U0 --word-diff-regex=.` can be helpful to verify this is only updating declarations, not changing code.
ACKs for top commit:
achow101:
ACK e5b6aef61221b621ad77b5f075a16897e08835bf
MarcoFalke:
Concept ACK e5b6aef61221b621ad77b5f075a16897e08835bf 🍨
Tree-SHA512: 3797745c90246794e2d55a2ee6e8b0ad5c811e4e03a242d3fdfeb68032f8787f0d48ed4097f6b7730f540220c0af99ef423cd9dbe7f76b2ec12e769a757a2c8d
3a45dc36a663ea67f13e7d5c413518b9385ec594 Change type of `backup_file` parameter in RestoreWallet/restoreWallet (Hennadii Stepanov)
213172c7348091794b173c2edf5f7f3bbe010912 refactor: Block unsafe std::string fs::path conversion copy_file calls (Hennadii Stepanov)
Pull request description:
This PR is an optional prerequisite for bitcoin/bitcoin#20744 "Use std::filesystem. Remove Boost Filesystem & System" which:
- makes further code changes safer
- prevents [some](https://cirrus-ci.com/task/6525835388649472) test failures on native Windows
ACKs for top commit:
ryanofsky:
Code review ACK 3a45dc36a663ea67f13e7d5c413518b9385ec594. Looks great! Thanks for debugging and fixing this and making #20744 smaller!
Tree-SHA512: c6dfaef6b45b9c268bc9ee9b943b9d679152c9d565ca4f86da8d33f8eb9b3cdbe9ba6df7b7578eacc0d00db6551048beff97419f86eb4b1d3182c43e2b4eb9a5
`fs::path` looks more native than `std::string` for a parameter which
represents a backup file. This change eliminates back-and-forth type
conversions.
There is no change in behavior. This just helps prepare for the
transition from boost::filesystem to std::filesystem by avoiding
copy_file calls that will be unsafe after the transition to
std::filesystem to due lack of a boost::filesystem::path::imbue
equivalent and inability to set a predictable locale.
