Bitcoin Core

Set minimum supported Windows version to 1903 (May 2019 Update)

This version is the minimum required to support the UTF-8 code page
(CP_UTF8).

Simplify fs::path by dropping filename() and make_preferred() overloads

These overloads were needed to allow passing `fs::path` objects directly to
libstdc++'s `fstream` constructors, but after the previous commit, there is no
longer any remaining code that does pass `fs::path` objects to `fstream`
constructors. Writing new code which does this is also discouraged because the
standard has been updated in https://wg21.link/lwg3430 to disallow it.

Dropping these also means its no longer possible to pass `fs::path` arguments
directly to `fstream::open` in libstdc++, which is somewhat unfortunate but not
a big loss because it is already not possible to pass them to the constructor.
So this commit updates `fstream::open` calls.

Additionally, this change required updates to src/bitcoin.cpp since it was
relying on the overloaded filename() method.

Fix windows libc++ fs::path fstream compile errors

As reported by hebasto in https://github.com/bitcoin/bitcoin/issues/33545,
newer libc++ versions implementing https://wg21.link/lwg3430 will no longer
implicitly convert `fs::path` objects to `std::filesystem::path` objects when
constructing `std::ifstream` and `std::ofstream` types.

This is not a problem in Unix systems since `fs::path` objects use
`std::string` as their native string type, but it causes compile errors on
Windows which use `std::wstring` as their string type, since `fstream`s can't
be constructed from `wstring`s.

Fix the windows libc++ compile errors by adding a new `fs::path::std_path()`
method and using it construct `fstream`s more portably.

Additionally, delete `fs::path`'s implicit `native_string` conversion so these
errors will not go undetected in the future, even though there is not currently
a CI job testing Windows libc++ builds.

doc: Update multisig-tutorial.md to use multipath descriptors

Update doc/multisig-tutorial.md to use a single multipath descriptor
instead of separate external/internal descriptors, per PR #22838.
Extract one xpub per participant, build a multipath descriptor with
<0;1> change index, and use getdescriptorinfo to append the checksum.
Clarify importdescriptors expands multipath descriptors into internal
and external forms. Tested shell snippets to confirm equivalent
listdescriptors output as the two-descriptor method.

Added missing loadwallet command for multisig_wallet_01

test: Use multipath descriptors in the functional wallet test
wallet_multisig_descriptor_psbt as this is intended as documentation

doc: replace `bitcoin-cli` with `bitcoin rpc` in multisig-tutorial.md

removed -named parameter where possible.

fixed a couple bugs where -signet was not passed

the call to getcoins.py requires the bitcoin-cli command still

test: addrman: check isTerrible when time is more than 10min in the future

[test] wallet send 3 generation TRUC

[wallet] never try to spend from unconfirmed TRUC that already has ancestors

chain: make use of pskip in LastCommonAncestor (optimization)

By using the pskip pointer, which regularly allows jumping back much faster
than pprev, the forking point between two CBlockIndex entries can be found
much faster.

A simulation shows that no more than 136 steps are needed to jump anywhere
within the first 2^20 block heights, and on average 65 jumps for uniform
forking points around that height.

tests: add unit tests for CBlockIndex::GetAncestor and LastCommonAncestor

ci: Check windows manifests for all executables

The other executables have manifests and these should be checked in
addition to bitcoind. Skipping fuzz.exe, bench_bitcoin.exe and
test_bitcoin-qt.exe as they do not have manifests.

ci: use a more generic way of finding mt.exe

This sets up a vs developer command prompt and should hopefully should
be more resilient to upstream changes

Co-authored-by: David Gumberg <davidzgumberg@gmail.com>

refactor: increase string_view usage

Update select functions that take a const std::string& to take a
std::string_view instead. In a next commit, this allows us to use
the {Arg,MaybeArg}<std::string_view> helper.

rpc: refactor: use more (Maybe)Arg<std::string_view>

Use the {Arg,MaybeArg}<std::string_view> helper in all places where
it is a trivial change. In many places, this simplifies the logic
and reduces duplication of default values.

rpc: refactor: use string_view in Arg/MaybeArg

Modernizes interface by not forcing users to deal with raw pointers,
without adding copying overhead. Generalizes the logic of whether
we return by value or by optional/pointer.

In cases where functions take a `const std::string&` and it would
be too much work to update them, a string copy is made (which was
already happening anyway).

net: support overriding the proxy selection in ConnectNode()

Normally `ConnectNode()` would choose whether to use a proxy and which
one. Make it possible to override this from the callers and same for
`OpenNetworkConnection()` - pass down the proxy to `ConnectNode()`.

Document both functions.

This is useful if we want to open connections to IPv4 or IPv6 peers
through the Tor SOCKS5 proxy.

Also have `OpenNetworkConnection()` return whether the connection
succeeded or not. This can be used when the caller needs to keep track
of how many (successful) connections were opened.

refactor: untangle assumevalid decision branches

Flatten nested conditionals into a linear gating sequence for readability and precise logging. No functional change, TODOs are addressed in next commit

log: split assumevalid ancestry-failure-reason message

When the assumevalid ancestry check fails, log a precise reason:
- "block height above assumevalid height" if the block is above the assumevalid block (the default reason)
- "block not in of assumevalid chain" otherwise

The new split was added under the existing condition to simplify conceptually that the two cases are related.
It could still be useful to know when the block is just above the assumevalid block or when it's not even on the same chain.

Update the functional test to assert the new reason strings. No behavior change.

Co-authored-by: Hodlinator <172445034+hodlinator@users.noreply.github.com>

validation: log initial script verification state

Replaced `atomic<bool>` with `std::optional<bool>` (logged once on first observation). Safe because `ConnectBlock` holds `cs_main`.\
After this change, the state is logged before the very first `UpdateTip` line.

Co-authored-by: Eunovo <eunovo9@gmail.com>
Co-authored-by: Hodlinator <172445034+hodlinator@users.noreply.github.com>
Co-authored-by: w0xlt <woltx@protonmail.com>

log: separate script verification reasons

Replace `fScriptChecks` with `script_check_reason` and log the precise reason when checks are enabled; log a plain "Disabling" when they are skipped.
Adjust the functional test to assert the new reason strings.

Co-authored-by: w0xlt <woltx@protonmail.com>
Co-authored-by: Eunovo <eunovo9@gmail.com>
Co-authored-by: Hodlinator <172445034+hodlinator@users.noreply.github.com>
Co-authored-by: TheCharlatan <seb.kung@gmail.com>
Co-authored-by: Andrew Toth <andrewstoth@gmail.com>

test: add assumevalid scenarios scaffold

Increase the test to 6 nodes and add flows for baseline, deep anchor, and too-recent cases, plus scaffolding for off-best-header, not-in-assumevalid,
and reindex gates.
Assertions are minimal here; follow-ups add reason checks.

Co-authored-by: Hodlinator <172445034+hodlinator@users.noreply.github.com>

init: Signal m_tip_block_cv on Ctrl-C

Signal m_tip_block_cv when Ctrl-C is pressed or SIGTERM is received, the same
way it is currently signalled when the `stop` RPC is called. This lets RPC
calls like `waitforblockheight` and IPC calls like `waitTipChanged` be
interrupted, instead of waiting for their original timeouts and delaying
shutdown.

Historical notes:

- The behavior where `stop` RPC signals `m_tip_block_cv`, but CTRL-C does not,
has been around since the condition variable was introduced in #30409
(7eccdaf16081d6f624c4dc21df75b0474e049d2b).
- The signaling was later moved without changing behavior in #30967
(5ca28ef28bcca1775ff49921fc2528d9439b71ab). This commit moves it again to
the Interrupt() function, which is probably the place it should have been
added initially, so it works for Ctrl-C shutdowns as well as `stop`
shutdowns.
- A Qt shutdown bug calling wait methods was fixed previously in #18452
(da73f1513a637a9f347b64de66564d6cdb2541f8), and this change updates that
fix to avoid the hang happening again in Qt.

net: change FindNode() to not return a node and rename it

All callers of `CConnman::FindNode()` use its return value `CNode*` only
as a boolean null/notnull. So change that method to return `bool`.

This removes the dangerous pattern of handling a `CNode` object (the
return value of `FindNode()`) without holding `CConnman::m_nodes_mutex`
and without having that object's reference count incremented for the
duration of the usage.

Also rename the method to better describe what it does.

doc: clarify peer address in getpeerinfo and addnode RPC help

The returned value in `getpeerinfo/addr` could be a hostname as well as
an IP address and the `:port` part could be missing. It is displayed
from `CNode::m_addr_name` which could have been set from RPC `addnode`
where the argument is allowed to be a hostname and an optional port.

net: avoid recursive m_nodes_mutex lock in DisconnectNode()

Have `CConnman::DisconnectNode()` iterate `m_nodes` itself instead of
using `FindNode()`. This avoids recursive mutex lock and drops the only
caller of `FindNode()` which used the return value for something else
than a boolean found/notfound.

fuzz: Drop unused workaround after Apple-Clang bump