mdbx package code
Copyright (c) 2026 Pedro Baltazar
License: MIT

Covers everything outside src/vendor/: the R sources under R/, the binding
layer src/r_mdbx.cpp, src/r_mdbx.h, src/r_flags.cpp, src/r_mdbx_hooks.cpp and
src/r_mdbx_hooks.h, the cpp11-generated src/cpp11.cpp and R/cpp11.R, the build
glue src/Makevars and src/Makevars.win, and the contents of man/ and tests/.
The same applies to the maintainer scripts under tools/ in the source
repository, which are not part of the distributed package.

Vendored third-party code
=========================

Component: libmdbx (aka MDBX)
Location: src/vendor/libmdbx
Upstream: https://libmdbx.dqdkfa.ru
Copyright (c) 2015-2026 Leonid Yuriev <leo@yuriev.ru>
License: Apache-2.0

The vendored files are mdbx.c, mdbx.h and mdbx-internals.h -- the three files
that constitute the official libmdbx amalgamation -- together with the upstream
LICENSE, NOTICE and COPYRIGHT, which are retained verbatim in
src/vendor/libmdbx and apply to the files there. libmdbx's command-line tools,
C++ API, test suite and build system are not vendored.

The sources were taken from release tag v0.14.3 (tag object
cf3e13938bf974260872e629713f6ecf30e62030, commit
f7a3a9323cacacfa9dc6137ae7a7252a67744ff0) via upstream's GitHub mirror at
https://github.com/erthink/libmdbx. Per-file SHA-256 digests of the pristine
sources are recorded in .agents/vendoring.md in the package's source
repository.

Local modifications to the vendored sources, which constitute the notice
required by section 4(b) of the Apache License, are confined to
src/vendor/libmdbx/mdbx.c, src/vendor/libmdbx/mdbx.h and
src/vendor/libmdbx/mdbx-internals.h. They route libmdbx's panic path through a
package-owned guard that marks the owning handle unusable and raises an R
condition instead of calling the platform assert handler or abort(); send log
output through R's console instead of stderr; read NT_TIB::Self directly rather
than through __readgsqword(), which avoids a false-positive -Warray-bounds from
Rtools' MinGW headers; remove nine upstream diagnostic-suppression pragmas
(#pragma GCC/clang diagnostic ignored ...), which are unnecessary under R's
compilation flags and trip CRAN's pragma check; and restrict the compatibility
definitions of bool, true, false and nullptr to compilers older than C23, which
promoted all four to keywords; and declare three trailing arrays that are
deliberately indexed past their declared length (the dirty-page list, the
defragmentation map list and the write-ring gather list) as C99 flexible array
members, or index them through a pointer, so that bounds-checking sanitizers do
not report them. Allocation sizes are unchanged. Together these ensure no compiled code writes to
stderr or terminates the R process. Each change is also recorded as a patch in
tools/patches/ in the package's source repository. LICENSE, NOTICE and COPYRIGHT
are unmodified.

Third-party code within libmdbx
===============================

libmdbx was derived from LMDB in 2015 and subsequently rewritten. The copyright
notices and licences of that ancestry are reproduced in full in
src/vendor/libmdbx/COPYRIGHT, and are in summary:

Component: LMDB
Copyright (c) 2011-2015 Howard Chu, Symas Corp. All rights reserved.
License: OpenLDAP Public License

Component: btree.c, from which LMDB derived code
Copyright (c) 2009, 2010 Martin Hedenfalk <martin@bzero.se>
License: ISC-style permissive licence