Bitcoin Core

test: socket error handling in HTTPServer using ErrorSock mock socket

Implements a child class of DynSock which is used as the mock
socket for HTTPServer unit tests. The ErrorSock::Send() method
raises a non-permanent error on the first HTTPRequest::WriteReply()
and then succeeds after the second.

In httpserver_tests.cpp use this mechanism to ensure that the
server retries a send operation if such an error is encountered,
and cover both optimistic (worker thread WriteReply()) and
non-optimistic (I/O thread SocketHandlerConnected()) send paths.

http: prevent race condition between worker thread and I/O thread

This prevents a losing race condition that could prevent the server
from reading requests from an HTTP client.

A connected socket can either be written to or read from based on the
result of GenerateWaitSockets(). That method checks the HTTPRemoteClient
flag m_send_ready. If it's `true` the implication is that there is
data in the client's send buffer ready to go. Once that data is sent
and the buffer is empty, MaybeSendBytesFromBuffer() sets it `false` again.

The sad case was when a worker thread calling WriteReply() adds
data to the send buffer, but before it sets m_send_ready to `true`,
the I/O thread sends that data and empties the buffer. With the
buffer unexpectedly empty, WriteReply() sets m_send_ready to `true`.

The effect of this is that the socket will stay in "write" mode
with nothing to write. With nothing to write, MaybeSendBytesFromBuffer()
never sets it back to `false` and the socket is stuck forever.

depends: add openbsd_LDFLAGS

ci: add openBSD cross CI job

wallet: Replace CWalletTx's vOrderForm with specific fields

vOrderForm contained 2 kinds of strings: BIP 21 messages, and BIP 70
Payment Requests. Instead of having both inside of a single vOrderForm
field that is opaque, split them into separate std::vector<std::string>
to contain this metadata.

wallet: Drop vOrderForm from CommitTransaction

This parameter is only used to pass in the "Messages" from the GUI.
Instead of making it opaque by putting those into vOrderForm, use a
specific dedicated parameter for providing the messages.

fuzz: restore CreateSock in PCP targets

scripted-diff: Rename `StatusLevel::{INFO,WARN,ERR}`

The `ERR` macro is defined on illumos-based systems in the `regset.h`
header included by the Boost.Test framework, which may cause a
compilation error.

-BEGIN VERIFY SCRIPT-

ren() { sed -i "s/\<$1\>/$2/g" $( git grep -l "$1" ./src/qt/psbtoperationsdialog.* ) ; }
ren StatusLevel::INFO StatusLevel::Info
ren INFO Info
ren StatusLevel::WARN StatusLevel::Warn
ren WARN Warn
ren StatusLevel::ERR StatusLevel::Error
ren ERR Error

-END VERIFY SCRIPT-

scripted-diff: Rename `Sock::{RECV,SEND,ERR}`

The `ERR` macro is defined on illumos-based systems in the `regset.h`
header included by the Boost.Test framework, which causes a compilation
error.

-BEGIN VERIFY SCRIPT-

ren1() { sed -i "s/\<$1\>/$2/g" $( git grep -l "$1" ./src/util/sock.* ./src/httpserver.h ) ; }
ren1 RECV RecvEvent
ren1 SEND SendEvent
ren1 ERR ErrorEvent

ren2() { sed -i "s/\<$1\>/$2/g" $( git grep -l "$1" ./src/ ) ; }
ren2 Sock::RECV Sock::RecvEvent
ren2 Sock::SEND Sock::SendEvent
ren2 Sock::ERR Sock::ErrorEvent

-END VERIFY SCRIPT-

util, refactor: Rename local `ERR` in `Sock::Accept`

The local `static constexpr auto ERR` shadowed the `Sock::ERR` static
data member. Rename it to `accept_error`, per the Developer Notes'
shadowing guidance.

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

ci: Bump tsan config to ubuntu:26.04 with -U_FORTIFY_SOURCE

log: expose -logratelimit option

The existing `-logratelimit` option can disable log rate limiting, but it is hidden from ordinary help because it is registered as `DEBUG_ONLY`.
Expose it in normal help so users affected by log suppression can discover the supported runtime knob.

script: qa: Improve Key::Fingerprint type safety

nanobench: fix perf counter buffer init

The perf counter read buffer comment says the vectors start with three metadata slots, but brace initialization creates one element with value 3.
Normal benchmark construction usually hides this because successful `monitor()` calls resize the buffers before `updateResults()`, while failed setup sets `mHasError` before the indexed reads.
Initialize the vectors with the size constructor so a default-constructed `LinuxPerformanceCounters` object satisfies the `read_format` invariant instead of relying on that construction path.
Reproducer: https://godbolt.org/z/scE8rMd8Y

test: add interface_gui.py to test bitcoin-gui startup via RPC

Adds a functional test that starts bitcoin-gui (via the bitcoin wrapper
with "gui" subcommand) using QT_QPA_PLATFORM=minimal for headless
operation, then verifies it responds to a stop RPC call. This catches
startup regressions in the GUI that have no CI coverage today.

Extends the test framework to support use_gui=True in TestNode, which
invokes "bitcoin gui" instead of "bitcoin node" and automatically sets
QT_QPA_PLATFORM=minimal. Adds BUILD_GUI to test/config.ini.in and
is_gui_compiled()/skip_if_no_gui() helpers to BitcoinTestFramework.

Co-Authored-By: MarcoFalke <*~=`'#}+{/-|&$^_@721217.xyz>
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

cmake: Remove `SelectLibraryConfigurations` from `FindQRencode` module

Co-authored-by: Daniel Pfeifer <daniel@pfeifer-mail.de>

depends: Remove unused `lib/pkgconfig` in `qrencode` package

cmake: Drop optional `PkgConfig` use in `FindQRencode` module

doc: add send RPC release note

doc: Clarify build docs about `pkgconf` / `pkg-config` requirements

wallet: remove experimental warning from send RPCs

ci: remove some packages from Chimera job

This doesn't build QT, so drop ninja and xz, and add a comment.
With libevent removed, and no Qt build, we can also drop pkgconf.

Add CI job for riscv bare metal

Add CI job for producing a static bare metal binary

build: Add option for building for bare metal envs

A bare metal build is now supported by setting CMAKE_SYSTEM_NAME=Generic

Skip the platform-dependent feature checks, such as threads and atomics,
which are typically not available on bare metal. Also only make the
boost headers mandatory if they exist for the target.

Also exclude aes from the crypto library, since that requires the secure
allocator, which uses more advance features, such as mutexes.