mdbx: выпуск 0.12.10 "СЭМ"

Поддерживающий выпуск с исправлением обнаруженных ошибок и устранением недочетов в память Героя России гвардии майора Дмитрия Семёнова с позывным "СЭМ". Значимые исправления и доработки: --------------------------------- - Устранение унаследованной от LMDB ошибки приводящей к повреждению БД при использовании `MDBX_DUPFIXED`. - Исправление ложной ошибки `MDBX_CORRUPTED (-30796)` в сценарии работы в режиме `MDBX_DUPFIXED` и нечетной длинной мульти-значений. - Исправление недочета корректировки сопутствующих курсоров при разделении страницы по сценарию добавления пустой страницы слева. - Доработка `rebalance()` ради уменьшения WAF. - Исправление assert-проверки внутри `check_txn()` для случая завершенных транзакций в режиме `MDBX_NO_TLS`. Последствий ошибки, кроме срабатывания assert-проверки в отладочных сборках, нет. - Устранение ошибки при открытии БД на файловой системе только-для-чтения. - Удалены излишне строгие проверки в утилите `mdbx_chk`, которые приводили к ложно-позитивным ошибкам при проверке БД после серии последних доработок. Более подробная информация в [ChangeLog](https://libmdbx.dqdkfa.ru/md__change_log.html). git diff' stat: 19 commits, 57 files changed, 751 insertions(+), 331 deletions(-) Signed-off-by: Леонид Юрьев (Leonid Yuriev) <leo@yuriev.ru>
mdbx-chk: не считаем ошибкой под-страницы без данных пользователя.
2025-12-15 16:42:22 +08:00 · 2024-03-13 14:57:38 +03:00 · 2024-03-12 09:02:50 +03:00 · 2024-03-12 02:38:17 +03:00 · 2024-03-11 00:34:04 +03:00 · 2024-03-06 22:58:31 +03:00
59 changed files with 1418 additions and 732 deletions
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,5 @@
 ##
-##  Copyright 2020-2023 Leonid Yuriev <leo@yuriev.ru>
+##  Copyright 2020-2024 Leonid Yuriev <leo@yuriev.ru>
 ##  and other libmdbx authors: please see AUTHORS file.
 ##  All rights reserved.
 ##
--- a/2
+++ b/2
@@ -1,4 +1,4 @@
-Copyright 2015-2023 Leonid Yuriev <leo@yuriev.ru>.
+Copyright 2015-2024 Leonid Yuriev <leo@yuriev.ru>.
 Copyright 2011-2015 Howard Chu, Symas Corp.
 Copyright 2015,2016 Peter-Service R&D LLC.
 All rights reserved.
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -4,6 +4,151 @@ ChangeLog
 English version [by Google](https://gitflic-ru.translate.goog/project/erthink/libmdbx/blob?file=ChangeLog.md&_x_tr_sl=ru&_x_tr_tl=en)
 and [by Yandex](https://translated.turbopages.org/proxy_u/ru-en.en/https/gitflic.ru/project/erthink/libmdbx/blob?file=ChangeLog.md).

+## v0.12.10 "СЭМ" от 2024-03-12
+
+Поддерживающий выпуск с исправлением обнаруженных ошибок и устранением недочетов
+в память Героя России гвардии майора Дмитрия Семёнова с позывным "СЭМ".
+
+```
+git diff' stat: 19 commits, 57 files changed, 751 insertions(+), 331 deletions(-)
+Signed-off-by: Леонид Юрьев (Leonid Yuriev) <leo@yuriev.ru>
+```
+
+Благодарности:
+
+ - [Dvir H](https://t.me/Dvirsw) за [сообщение](https://t.me/libmdbx/5368)
+   об ошибке `MDBX_CORRUPTED` в сценарии работы в режиме `MDBX_DUPFIXED` и нечетной длинной
+   мульти-значений, с предоставлением точного минимального сценария воспроизведения.
+
+Значимые исправления и доработки:
+
+ - Устранение унаследованной от LMDB ошибки приводящей к повреждению БД при использовании `MDBX_DUPFIXED`.
+   Проблема была выявлена при расширении тестов сценариями с длинными мульти-значениями в режиме `MDBX_DUPFIXED`.
+   Сообщений о проявлении этой ошибки в эксплуатационных/продуктовых средах не поступало.
+
+   На LEAF2-страниц, используемых для компактного хранения мульти-значений фиксированной длины,
+   выполнялось резервирование места без учета возможности превышения размера страниц,
+   с последующим переполнением, повреждением структуры БД и/или повреждением содержимого ОЗУ.
+
+   Вероятность проявления ошибки существенно увеличивалась с увеличением размера/длины
+   мульти-значений/дубликатов и уменьшением размера страницы БД. Поэтому при использовании `MDBX_INTEGERDUP`
+   вероятность проявления близка к нулю, а сценарий такого проявления найти не удалось.
+
+   В MDBX ошибка присутствовала с момента отделения проекта от LMDB,
+   где эта ошибка присутствует более 11 лети, по настоящее время.
+
+ - Исправление ложной ошибки `MDBX_CORRUPTED (-30796)` в сценарии работы
+   в режиме `MDBX_DUPFIXED` и нечетной длинной мульти-значений.
+
+ - Исправление недочета корректировки сопутствующих курсоров при разделении страницы
+   по сценарию добавления пустой страницы слева.
+
+ - Доработка `rebalance()` ради уменьшения WAF. Новый функционал, включая
+   контролируемую пользователем опцию `enum MDBX_option_t`, будет доступен
+   в выпусках ветки `0.13.x`, а в этом выпуске доработка сводится к тактике
+   не-вовленичения чистой страницы при нехватке запаса страниц в ходе обновления GC,
+   за счет ухудшения баланса дерева страниц.
+
+ - Устранение упущения приводящего к нелогичной ситуации
+   `me_dxb_mmap.curren > me_dxb_mmap.limit` при "дребезге" размера БД.
+   В текущем понимании, последствий кроме срабатывания assert-проверки нет, а
+   вероятность проявления близка к нулю.
+
+ - Исправление в функционале обхода дерева, используемого утилитой
+   `mdbx_chk`, подсчета места затраченного на выравнивание на вложенной
+   под-странице, в случае нечетного количества dupfixed-элементов нечетного
+   размера.
+   Сообщений о проявлении этой ошибки в эксплуатационных/продуктовых средах не поступало.
+
+ - Исправление assert-проверки внутри `check_txn()` для случая завершенных транзакций в режиме `MDBX_NO_TLS`.
+   Последствий ошибки, кроме срабатывания assert-проверки в отладочных сборках, нет.
+
+ - Устранение ошибки при открытии БД на файловой системе только-для-чтения.
+
+ - Удалены излишне строгие проверки в утилите `mdbx_chk`, которые
+   приводили к ложно-позитивным ошибкам при проверке БД после серии
+   последних доработок. Подробности см в комментариях к коммитам [781b3f64d52b73cbaeb00a55811d1247c25624a8](https://gitflic.ru/project/erthink/libmdbx/commit/781b3f64d52b73cbaeb00a55811d1247c25624a8)
+   и [0741c81cfd8dc0864fcf55e04192b2207c8f68f7](https://gitflic.ru/project/erthink/libmdbx/commit/0741c81cfd8dc0864fcf55e04192b2207c8f68f7).
+
+Прочее:
+
+ - Расширение стохастического теста dupfixed-сценариями.
+ - Корректировка условия в assert-проверке для `MDBX_TXN_DRAINED_GC`.
+ - Добавление в jitter-сценарий простого теста сброса и перезапуска читающих транзакций.
+ - Вынужденное продолжение очистки/рефакторинга унаследованных ребусов в `cursor_put_nochecklen()`.
+ - Фиксация транзакции при ошибках теста для последующего анализа содержимого БД.
+ - Сопутствующий рефакторинг `node_shrink()` для ясности исходного кода.
+ - Приведение в соответствие протоколируемых имен тестов опциям командной строки.
+ - Добавление cmoke-теста `extra/dupfixed_addodd`.
+
+
+--------------------------------------------------------------------------------
+
+
+## v0.12.9 "Ясень-4" от 2023-12-11
+
+Стабилизирующий выпуск с исправлением обнаруженных ошибок и устранением недочетов.
+
+```
+git diff' stat: 32 commits, 8 files changed, 667 insertions(+), 401 deletions(-)
+Signed-off-by: Леонид Юрьев (Leonid Yuriev) <leo@yuriev.ru>
+```
+
+Исправления и доработки:
+
+ - Ликвидация зависимости от ранее удаленной опции `MDBX_ENABLE_PREFAULT`, из-за
+   чего опция `MDBX_ENABLE_MINCORE` не включалась автоматически, что приводило
+   к не-активации соответствующего улучшения и не-достижению  декларируемого уровня
+   производительности в сценариях использования в режиме `MDBX_WRITEMAP`.
+
+ - Исправление авто-установки `MDBX_ENV_CHECKPID` при отключении использования
+   функционала `madvise()` посредством опции сборки `MDBX_ENABLE_MADVISE=0`.
+   Из-за чего при поддержке системой `madvise(MADV_DONTFORK)` не включался контроль pid.
+
+ - Добавлена проверка переданного ключа на `NULL` при обработке `MDBX_GET_MULTIPLE`.
+
+ - Добавлена проверка номеров корневых страниц в `coherency_check()`.
+
+ - Обеспечен `const` для начала и конца диапазона в аргументах `mdbx_estimate_range()`.
+
+ - Из разрабатываемой версии перенесены не-нарушающие совместимости доработки C++ API:
+
+     - добавлен тип `mdbx::cursor::estimation_result`, а поведение методов
+      `cursor::estimate()` унифицировано с `cursor::move()`;
+     - для предотвращения незаметного неверного использования API, для инициализации
+       возвращаемых по ссылке срезов, вместо пустых срезов задействован `slice::invalid()`;
+     - добавлены дополнительные C++ операторы преобразования к типам C API;
+     - для совместимости со старыми стандартами C++ и старыми версиями STL перенесены
+       в public классы `buffer::move_assign_alloc` и `buffer::copy_assign_alloc`;
+     - добавлен тип `mdbx::default_buffer`;
+     - для срезов и буферов добавлены методы `hex_decode()`, `base64_decode()`, `base58_decode()`;
+     - добавлен тип `mdbx::comparator` и функций `mdbx::default_comparator()`;
+     - добавлены статические методы `buffer::hex()`, `base64()`, `base58()`;
+     - для транзакций и курсоров добавлены методы `get_/set_context`;
+     - добавлен метод `cursor::clone()`;
+
+ - Поддержка base58 приведена в соответствии с черновиком RFC.
+
+ - Переработка/исправление `to_hex()` и `from_hex()`.
+
+ - Уменьшение `MDBX_opt_rp_augment_limit` по умолчанию до 1/3 от текущего количества страниц в БД.
+
+Мелочи:
+
+ - Удаление устаревших `mdbx_set_compare()` и `mdbx_set_dupsort()`.
+ - Корректировка определения `MDBX_LAST_ADDED_ERRCODE`.
+ - Добавление в C++ API забытого исключения `mdbx::duplicated_lck_file`.
+ - Обновление патча для старых версий buildroot.
+ - Использование в API `const MDBX_txn` где это возможно.
+ - Удаление устаревшего упоминания `MDBX_EAGAIN`.
+ - Проверка pid процесса только в функциях API требующих активной среды/env.
+ - Исправление опечаток в комментариях, в том числе  в doxygen-описании.
+ - В тестах для совместимости с проблемными версиями glibc и glibc++
+   устранено использование `std::stoull()`.
+
+
+--------------------------------------------------------------------------------
+

 ## v0.12.8 "Владимир Уткин" от 2023-10-17

@@ -379,7 +524,7 @@ Signed-off-by: Леонид Юрьев (Leonid Yuriev) <leo@yuriev.ru>

 - Добавлен явный выбор `tls_model("local-dynamic")` для обхода проблемы
   `relocation R_X86_64_TPOFF32 against FOO cannot be used with -shared`
-   из-за ошибки в CLANG приводящей к использованию неверного режима `ls_model`.
+   из-за ошибки в CLANG приводящей к использованию неверного режима `tls_model`.

 - Изменение тактики слияния страниц при удалении.
   Теперь слияние выполняется преимущественно с уже измененной/грязной страницей.
--- a/cmake/compiler.cmake
+++ b/cmake/compiler.cmake
@@ -1,4 +1,4 @@
-##  Copyright (c) 2012-2023 Leonid Yuriev <leo@yuriev.ru>.
+##  Copyright (c) 2012-2024 Leonid Yuriev <leo@yuriev.ru>.
 ##
 ##  Licensed under the Apache License, Version 2.0 (the "License");
 ##  you may not use this file except in compliance with the License.
--- a/cmake/profile.cmake
+++ b/cmake/profile.cmake
@@ -1,4 +1,4 @@
-##  Copyright (c) 2012-2023 Leonid Yuriev <leo@yuriev.ru>.
+##  Copyright (c) 2012-2024 Leonid Yuriev <leo@yuriev.ru>.
 ##
 ##  Licensed under the Apache License, Version 2.0 (the "License");
 ##  you may not use this file except in compliance with the License.
--- a/cmake/utils.cmake
+++ b/cmake/utils.cmake
@@ -1,4 +1,4 @@
-##  Copyright (c) 2012-2023 Leonid Yuriev <leo@yuriev.ru>.
+##  Copyright (c) 2012-2024 Leonid Yuriev <leo@yuriev.ru>.
 ##
 ##  Licensed under the Apache License, Version 2.0 (the "License");
 ##  you may not use this file except in compliance with the License.
--- a/mdbx.h
+++ b/mdbx.h
@@ -25,7 +25,7 @@ _The Future will (be) [Positive](https://www.ptsecurity.com). Всё будет

 \section copyright LICENSE & COPYRIGHT

-\authors Copyright (c) 2015-2023, Leonid Yuriev <leo@yuriev.ru>
+\authors Copyright (c) 2015-2024, Leonid Yuriev <leo@yuriev.ru>
 and other _libmdbx_ authors: please see [AUTHORS](./AUTHORS) file.

 \copyright Redistribution and use in source and binary forms, with or without
@@ -1937,7 +1937,7 @@ enum MDBX_error_t {
  MDBX_DUPLICATED_CLK = -30413,

  /* The last of MDBX-added error codes */
-  MDBX_LAST_ADDED_ERRCODE = MDBX_TXN_OVERLAPPING,
+  MDBX_LAST_ADDED_ERRCODE = MDBX_DUPLICATED_CLK,

 #if defined(_WIN32) || defined(_WIN64)
  MDBX_ENODATA = ERROR_HANDLE_EOF,
@@ -2119,7 +2119,8 @@ enum MDBX_option_t {
   * growth, or/and to the inability of put long values.
   *
   * The `MDBX_opt_rp_augment_limit` controls described limit for the current
-   * process. Default is 262144, it is usually enough for most cases. */
+   * process. By default this limit adjusted dynamically to 1/3 of current
+   * quantity of DB pages, which is usually enough for most cases. */
  MDBX_opt_rp_augment_limit,

  /** \brief Controls the in-process limit to grow a cache of dirty
@@ -2352,7 +2353,6 @@ LIBMDBX_API int mdbx_env_get_option(const MDBX_env *env,
 *                            doesn't exist.
 * \retval MDBX_EACCES        The user didn't have permission to access
 *                            the environment files.
- * \retval MDBX_EAGAIN        The environment was locked by another process.
 * \retval MDBX_BUSY          The \ref MDBX_EXCLUSIVE flag was specified and the
 *                            environment is in use by another process,
 *                            or the current process tries to open environment
@@ -4293,8 +4293,8 @@ mdbx_int64_from_key(const MDBX_val);
 * \retval MDBX_THREAD_MISMATCH  Given transaction is not owned
 *                               by current thread.
 * \retval MDBX_EINVAL   An invalid parameter was specified. */
-LIBMDBX_API int mdbx_dbi_stat(MDBX_txn *txn, MDBX_dbi dbi, MDBX_stat *stat,
-                              size_t bytes);
+LIBMDBX_API int mdbx_dbi_stat(const MDBX_txn *txn, MDBX_dbi dbi,
+                              MDBX_stat *stat, size_t bytes);

 /** \brief Retrieve depth (bitmask) information of nested dupsort (multi-value)
 * B+trees for given database.
@@ -4311,7 +4311,7 @@ LIBMDBX_API int mdbx_dbi_stat(MDBX_txn *txn, MDBX_dbi dbi, MDBX_stat *stat,
 *                               by current thread.
 * \retval MDBX_EINVAL       An invalid parameter was specified.
 * \retval MDBX_RESULT_TRUE  The dbi isn't a dupsort (multi-value) database. */
-LIBMDBX_API int mdbx_dbi_dupsort_depthmask(MDBX_txn *txn, MDBX_dbi dbi,
+LIBMDBX_API int mdbx_dbi_dupsort_depthmask(const MDBX_txn *txn, MDBX_dbi dbi,
                                           uint32_t *mask);

 /** \brief DBI state bits returted by \ref mdbx_dbi_flags_ex()
@@ -4343,13 +4343,13 @@ DEFINE_ENUM_FLAG_OPERATORS(MDBX_dbi_state_t)
 * \param [out] state  Address where the state will be returned.
 *
 * \returns A non-zero error value on failure and 0 on success. */
-LIBMDBX_API int mdbx_dbi_flags_ex(MDBX_txn *txn, MDBX_dbi dbi, unsigned *flags,
-                                  unsigned *state);
+LIBMDBX_API int mdbx_dbi_flags_ex(const MDBX_txn *txn, MDBX_dbi dbi,
+                                  unsigned *flags, unsigned *state);
 /** \brief The shortcut to calling \ref mdbx_dbi_flags_ex() with `state=NULL`
 * for discarding it result.
 * \ingroup c_statinfo */
 LIBMDBX_INLINE_API(int, mdbx_dbi_flags,
-                   (MDBX_txn * txn, MDBX_dbi dbi, unsigned *flags)) {
+                   (const MDBX_txn *txn, MDBX_dbi dbi, unsigned *flags)) {
  unsigned state;
  return mdbx_dbi_flags_ex(txn, dbi, flags, &state);
 }
@@ -4425,7 +4425,7 @@ LIBMDBX_API int mdbx_drop(MDBX_txn *txn, MDBX_dbi dbi, bool del);
 *                               by current thread.
 * \retval MDBX_NOTFOUND  The key was not in the database.
 * \retval MDBX_EINVAL    An invalid parameter was specified. */
-LIBMDBX_API int mdbx_get(MDBX_txn *txn, MDBX_dbi dbi, const MDBX_val *key,
+LIBMDBX_API int mdbx_get(const MDBX_txn *txn, MDBX_dbi dbi, const MDBX_val *key,
                         MDBX_val *data);

 /** \brief Get items from a database
@@ -4458,7 +4458,7 @@ LIBMDBX_API int mdbx_get(MDBX_txn *txn, MDBX_dbi dbi, const MDBX_val *key,
 *                               by current thread.
 * \retval MDBX_NOTFOUND  The key was not in the database.
 * \retval MDBX_EINVAL    An invalid parameter was specified. */
-LIBMDBX_API int mdbx_get_ex(MDBX_txn *txn, MDBX_dbi dbi, MDBX_val *key,
+LIBMDBX_API int mdbx_get_ex(const MDBX_txn *txn, MDBX_dbi dbi, MDBX_val *key,
                            MDBX_val *data, size_t *values_count);

 /** \brief Get equal or great item from a database.
@@ -4489,7 +4489,7 @@ LIBMDBX_API int mdbx_get_ex(MDBX_txn *txn, MDBX_dbi dbi, MDBX_val *key,
 *                               by current thread.
 * \retval MDBX_NOTFOUND      The key was not in the database.
 * \retval MDBX_EINVAL        An invalid parameter was specified. */
-LIBMDBX_API int mdbx_get_equal_or_great(MDBX_txn *txn, MDBX_dbi dbi,
+LIBMDBX_API int mdbx_get_equal_or_great(const MDBX_txn *txn, MDBX_dbi dbi,
                                        MDBX_val *key, MDBX_val *data);

 /** \brief Store items into a database.
@@ -4731,7 +4731,7 @@ mdbx_cursor_get_userctx(const MDBX_cursor *cursor);
 * \retval MDBX_THREAD_MISMATCH  Given transaction is not owned
 *                               by current thread.
 * \retval MDBX_EINVAL  An invalid parameter was specified. */
-LIBMDBX_API int mdbx_cursor_bind(MDBX_txn *txn, MDBX_cursor *cursor,
+LIBMDBX_API int mdbx_cursor_bind(const MDBX_txn *txn, MDBX_cursor *cursor,
                                 MDBX_dbi dbi);

 /** \brief Create a cursor handle for the specified transaction and DBI handle.
@@ -4764,7 +4764,7 @@ LIBMDBX_API int mdbx_cursor_bind(MDBX_txn *txn, MDBX_cursor *cursor,
 * \retval MDBX_THREAD_MISMATCH  Given transaction is not owned
 *                               by current thread.
 * \retval MDBX_EINVAL  An invalid parameter was specified. */
-LIBMDBX_API int mdbx_cursor_open(MDBX_txn *txn, MDBX_dbi dbi,
+LIBMDBX_API int mdbx_cursor_open(const MDBX_txn *txn, MDBX_dbi dbi,
                                 MDBX_cursor **cursor);

 /** \brief Close a cursor handle.
@@ -4807,7 +4807,7 @@ LIBMDBX_API void mdbx_cursor_close(MDBX_cursor *cursor);
 * \retval MDBX_EINVAL  An invalid parameter was specified.
 * \retval MDBX_BAD_DBI The cursor was not bound to a DBI-handle
 *                      or such a handle became invalid. */
-LIBMDBX_API int mdbx_cursor_renew(MDBX_txn *txn, MDBX_cursor *cursor);
+LIBMDBX_API int mdbx_cursor_renew(const MDBX_txn *txn, MDBX_cursor *cursor);

 /** \brief Return the cursor's transaction handle.
 * \ingroup c_cursors
@@ -5186,9 +5186,11 @@ LIBMDBX_API int mdbx_estimate_move(const MDBX_cursor *cursor, MDBX_val *key,
 * \param [out] distance_items  A pointer to store range estimation result.
 *
 * \returns A non-zero error value on failure and 0 on success. */
-LIBMDBX_API int mdbx_estimate_range(MDBX_txn *txn, MDBX_dbi dbi,
-                                    MDBX_val *begin_key, MDBX_val *begin_data,
-                                    MDBX_val *end_key, MDBX_val *end_data,
+LIBMDBX_API int mdbx_estimate_range(const MDBX_txn *txn, MDBX_dbi dbi,
+                                    const MDBX_val *begin_key,
+                                    const MDBX_val *begin_data,
+                                    const MDBX_val *end_key,
+                                    const MDBX_val *end_data,
                                    ptrdiff_t *distance_items);

 /** \brief The EPSILON value for mdbx_estimate_range()
--- a/mdbx.h++
+++ b/mdbx.h++
@@ -1,7 +1,7 @@
 /// \file mdbx.h++
 /// \brief The libmdbx C++ API header file.
 ///
-/// \author Copyright (c) 2020-2023, Leonid Yuriev <leo@yuriev.ru>.
+/// \author Copyright (c) 2020-2024, Leonid Yuriev <leo@yuriev.ru>.
 /// \copyright SPDX-License-Identifier: Apache-2.0
 ///
 /// Tested with:
@@ -362,8 +362,11 @@ using default_allocator = polymorphic_allocator;
 using default_allocator = legacy_allocator;
 #endif /* __cpp_lib_memory_resource >= 201603L */

-/// \brief Default singe-byte string.
-template <class ALLOCATOR = legacy_allocator>
+/// \brief Default buffer.
+using default_buffer = buffer<default_allocator, default_capacity_policy>;
+
+/// \brief Default single-byte string.
+template <class ALLOCATOR = default_allocator>
 using string = ::std::basic_string<char, ::std::char_traits<char>, ALLOCATOR>;

 using filehandle = ::mdbx_filehandle_t;
@@ -558,6 +561,7 @@ MDBX_DECLARE_EXCEPTION(something_busy);
 MDBX_DECLARE_EXCEPTION(thread_mismatch);
 MDBX_DECLARE_EXCEPTION(transaction_full);
 MDBX_DECLARE_EXCEPTION(transaction_overlapping);
+MDBX_DECLARE_EXCEPTION(duplicated_lck_file);
 #undef MDBX_DECLARE_EXCEPTION

 [[noreturn]] LIBMDBX_API void throw_too_small_target_buffer();
@@ -732,6 +736,8 @@ struct LIBMDBX_API_TYPE slice : public ::MDBX_val {
  slice &operator=(const slice &) noexcept = default;
  inline slice &operator=(slice &&src) noexcept;
  inline slice &operator=(::MDBX_val &&src);
+  operator MDBX_val *() noexcept { return this; }
+  operator const MDBX_val *() const noexcept { return this; }

 #if defined(DOXYGEN) ||                                                        \
    (defined(__cpp_lib_string_view) && __cpp_lib_string_view >= 201606L)
@@ -1321,8 +1327,7 @@ struct LIBMDBX_API to_base58 {
  /// \brief Returns the buffer size in bytes needed for
  /// [Base58](https://en.wikipedia.org/wiki/Base58) dump of passed slice.
  MDBX_CXX11_CONSTEXPR size_t envisage_result_length() const noexcept {
-    const size_t bytes =
-        source.length() / 8 * 11 + (source.length() % 8 * 43 + 31) / 32;
+    const size_t bytes = (source.length() * 11 + 7) / 8;
    return wrap_width ? bytes + bytes / wrap_width : bytes;
  }

@@ -1487,7 +1492,7 @@ struct LIBMDBX_API from_base58 {
  /// [Base58](https://en.wikipedia.org/wiki/Base58) dump from a passed slice to
  /// decoded data.
  MDBX_CXX11_CONSTEXPR size_t envisage_result_length() const noexcept {
-    return source.length() / 11 * 8 + source.length() % 11 * 32 / 43;
+    return source.length() /* могут быть все нули кодируемые один-к-одному */;
  }

  /// \brief Fills the destination with data decoded from
@@ -1575,10 +1580,6 @@ public:
 private:
  friend class txn;
  struct silo;
-  using move_assign_alloc =
-      allocation_aware_details::move_assign_alloc<silo, allocator_type>;
-  using copy_assign_alloc =
-      allocation_aware_details::copy_assign_alloc<silo, allocator_type>;
  using swap_alloc = allocation_aware_details::swap_alloc<silo, allocator_type>;
  struct silo /* Empty Base Class Optimization */ : public allocator_type {
    MDBX_CXX20_CONSTEXPR const allocator_type &get_allocator() const noexcept {
@@ -2070,6 +2071,11 @@ public:
  /// \todo buffer& operator>>(buffer&, ...) for reading (delegated to slice)
  /// \todo template<class X> key(X) for encoding keys while writing

+  using move_assign_alloc =
+      allocation_aware_details::move_assign_alloc<silo, allocator_type>;
+  using copy_assign_alloc =
+      allocation_aware_details::copy_assign_alloc<silo, allocator_type>;
+
  /// \brief Returns the associated allocator.
  MDBX_CXX20_CONSTEXPR allocator_type get_allocator() const {
    return silo_.get_allocator();
@@ -2338,6 +2344,126 @@ public:
    return slice_.as_pod<POD>();
  }

+  /// \brief Returns a new buffer with a hexadecimal dump of the slice content.
+  static buffer hex(const ::mdbx::slice &source, bool uppercase = false,
+                    unsigned wrap_width = 0,
+                    const allocator_type &allocator = allocator_type()) {
+    return source.template encode_hex<ALLOCATOR, CAPACITY_POLICY>(
+        uppercase, wrap_width, allocator);
+  }
+
+  /// \brief Returns a new buffer with a
+  /// [Base58](https://en.wikipedia.org/wiki/Base58) dump of the slice content.
+  static buffer base58(const ::mdbx::slice &source, unsigned wrap_width = 0,
+                       const allocator_type &allocator = allocator_type()) {
+    return source.template encode_base58<ALLOCATOR, CAPACITY_POLICY>(wrap_width,
+                                                                     allocator);
+  }
+  /// \brief Returns a new buffer with a
+  /// [Base64](https://en.wikipedia.org/wiki/Base64) dump of the slice content.
+  static buffer base64(const ::mdbx::slice &source, unsigned wrap_width = 0,
+                       const allocator_type &allocator = allocator_type()) {
+    return source.template encode_base64<ALLOCATOR, CAPACITY_POLICY>(wrap_width,
+                                                                     allocator);
+  }
+
+  /// \brief Returns a new buffer with a hexadecimal dump of the given pod.
+  template <typename POD>
+  static buffer hex(const POD &pod, bool uppercase = false,
+                    unsigned wrap_width = 0,
+                    const allocator_type &allocator = allocator_type()) {
+    return hex(mdbx::slice::wrap(pod), uppercase, wrap_width, allocator);
+  }
+
+  /// \brief Returns a new buffer with a
+  /// [Base58](https://en.wikipedia.org/wiki/Base58) dump of the given pod.
+  template <typename POD>
+  static buffer base58(const POD &pod, unsigned wrap_width = 0,
+                       const allocator_type &allocator = allocator_type()) {
+    return base58(mdbx::slice::wrap(pod), wrap_width, allocator);
+  }
+
+  /// \brief Returns a new buffer with a
+  /// [Base64](https://en.wikipedia.org/wiki/Base64) dump of the given pod.
+  template <typename POD>
+  static buffer base64(const POD &pod, unsigned wrap_width = 0,
+                       const allocator_type &allocator = allocator_type()) {
+    return base64(mdbx::slice::wrap(pod), wrap_width, allocator);
+  }
+
+  /// \brief Returns a new buffer with a hexadecimal dump of the slice content.
+  buffer encode_hex(bool uppercase = false, unsigned wrap_width = 0,
+                    const allocator_type &allocator = allocator_type()) const {
+    return slice().template encode_hex<ALLOCATOR, CAPACITY_POLICY>(
+        uppercase, wrap_width, allocator);
+  }
+
+  /// \brief Returns a new buffer with a
+  /// [Base58](https://en.wikipedia.org/wiki/Base58) dump of the slice content.
+  buffer
+  encode_base58(unsigned wrap_width = 0,
+                const allocator_type &allocator = allocator_type()) const {
+    return slice().template encode_base58<ALLOCATOR, CAPACITY_POLICY>(
+        wrap_width, allocator);
+  }
+  /// \brief Returns a new buffer with a
+  /// [Base64](https://en.wikipedia.org/wiki/Base64) dump of the slice content.
+  buffer
+  encode_base64(unsigned wrap_width = 0,
+                const allocator_type &allocator = allocator_type()) const {
+    return slice().template encode_base64<ALLOCATOR, CAPACITY_POLICY>(
+        wrap_width, allocator);
+  }
+
+  /// \brief Decodes hexadecimal dump from the slice content to returned buffer.
+  static buffer hex_decode(const ::mdbx::slice &source,
+                           bool ignore_spaces = false,
+                           const allocator_type &allocator = allocator_type()) {
+    return source.template hex_decode<ALLOCATOR, CAPACITY_POLICY>(ignore_spaces,
+                                                                  allocator);
+  }
+
+  /// \brief Decodes [Base58](https://en.wikipedia.org/wiki/Base58) dump
+  /// from the slice content to returned buffer.
+  static buffer
+  base58_decode(const ::mdbx::slice &source, bool ignore_spaces = false,
+                const allocator_type &allocator = allocator_type()) {
+    return source.template base58_decode<ALLOCATOR, CAPACITY_POLICY>(
+        ignore_spaces, allocator);
+  }
+
+  /// \brief Decodes [Base64](https://en.wikipedia.org/wiki/Base64) dump
+  /// from the slice content to returned buffer.
+  static buffer
+  base64_decode(const ::mdbx::slice &source, bool ignore_spaces = false,
+                const allocator_type &allocator = allocator_type()) {
+    return source.template base64_decode<ALLOCATOR, CAPACITY_POLICY>(
+        ignore_spaces, allocator);
+  }
+
+  /// \brief Decodes hexadecimal dump
+  /// from the buffer content to new returned buffer.
+  buffer hex_decode(bool ignore_spaces = false,
+                    const allocator_type &allocator = allocator_type()) const {
+    return hex_decode(slice(), ignore_spaces, allocator);
+  }
+
+  /// \brief Decodes [Base58](https://en.wikipedia.org/wiki/Base58) dump
+  /// from the buffer content to new returned buffer.
+  buffer
+  base58_decode(bool ignore_spaces = false,
+                const allocator_type &allocator = allocator_type()) const {
+    return base58_decode(slice(), ignore_spaces, allocator);
+  }
+
+  /// \brief Decodes [Base64](https://en.wikipedia.org/wiki/Base64) dump
+  /// from the buffer content to new returned buffer.
+  buffer
+  base64_decode(bool ignore_spaces = false,
+                const allocator_type &allocator = allocator_type()) const {
+    return base64_decode(slice(), ignore_spaces, allocator);
+  }
+
  /// \brief Reserves storage space.
  void reserve(size_t wanna_headroom, size_t wanna_tailroom) {
    wanna_headroom = ::std::min(::std::max(headroom(), wanna_headroom),
@@ -2982,6 +3108,7 @@ struct LIBMDBX_API_TYPE map_handle {
  map_handle(const map_handle &) noexcept = default;
  map_handle &operator=(const map_handle &) noexcept = default;
  operator bool() const noexcept { return dbi != 0; }
+  operator MDBX_dbi() const { return dbi; }

  using flags = ::MDBX_db_flags_t;
  using state = ::MDBX_dbi_state_t;
@@ -3007,6 +3134,14 @@ struct LIBMDBX_API_TYPE map_handle {
  };
 };

+using comparator = ::MDBX_cmp_func *;
+inline comparator default_comparator(key_mode mode) noexcept {
+  return ::mdbx_get_keycmp(static_cast<MDBX_db_flags_t>(mode));
+}
+inline comparator default_comparator(value_mode mode) noexcept {
+  return ::mdbx_get_keycmp(static_cast<MDBX_db_flags_t>(mode));
+}
+
 /// \brief Key-value pairs put mode.
 enum put_mode {
  insert_unique = MDBX_NOOVERWRITE, ///< Insert only unique keys.
@@ -3444,7 +3579,7 @@ public:
  inline void *get_context() const noexcept;

  /// \brief Sets the application context associated with the environment.
-  inline env &set_context(void *);
+  inline env &set_context(void *your_context);

  /// \brief Sets threshold to force flush the data buffers to disk, for
  /// non-sync durability modes.
@@ -3802,6 +3937,12 @@ public:
  /// \brief Return the transaction's ID.
  inline uint64_t id() const;

+  /// \brief Returns the application context associated with the transaction.
+  inline void *get_context() const noexcept;
+
+  /// \brief Sets the application context associated with the transaction.
+  inline txn &set_context(void *your_context);
+
  /// \brief Checks whether the given data is on a dirty page.
  inline bool is_dirty(const void *ptr) const;

@@ -3838,7 +3979,7 @@ public:
  txn_managed start_nested();

  /// \brief Opens cursor for specified key-value map handle.
-  inline cursor_managed open_cursor(map_handle map);
+  inline cursor_managed open_cursor(map_handle map) const;

  /// \brief Open existing key-value map.
  inline map_handle open_map(
@@ -4037,10 +4178,12 @@ public:
    put_multiple(map, key, vector.data(), vector.size(), mode);
  }

-  inline ptrdiff_t estimate(map_handle map, pair from, pair to) const;
-  inline ptrdiff_t estimate(map_handle map, slice from, slice to) const;
-  inline ptrdiff_t estimate_from_first(map_handle map, slice to) const;
-  inline ptrdiff_t estimate_to_last(map_handle map, slice from) const;
+  inline ptrdiff_t estimate(map_handle map, const pair &from,
+                            const pair &to) const;
+  inline ptrdiff_t estimate(map_handle map, const slice &from,
+                            const slice &to) const;
+  inline ptrdiff_t estimate_from_first(map_handle map, const slice &to) const;
+  inline ptrdiff_t estimate_to_last(map_handle map, const slice &from) const;
 };

 /// \brief Managed database transaction.
@@ -4121,6 +4264,7 @@ public:
  inline cursor &operator=(cursor &&other) noexcept;
  inline cursor(cursor &&other) noexcept;
  inline ~cursor() noexcept;
+  inline cursor_managed clone(void *your_context = nullptr) const;
  MDBX_CXX14_CONSTEXPR operator bool() const noexcept;
  MDBX_CXX14_CONSTEXPR operator const MDBX_cursor *() const;
  MDBX_CXX14_CONSTEXPR operator MDBX_cursor *();
@@ -4129,6 +4273,12 @@ public:
  friend MDBX_CXX11_CONSTEXPR bool operator!=(const cursor &a,
                                              const cursor &b) noexcept;

+  /// \brief Returns the application context associated with the cursor.
+  inline void *get_context() const noexcept;
+
+  /// \brief Sets the application context associated with the cursor.
+  inline cursor &set_context(void *your_context);
+
  enum move_operation {
    first = MDBX_FIRST,
    last = MDBX_LAST,
@@ -4153,10 +4303,13 @@ public:

  struct move_result : public pair_result {
    inline move_result(const cursor &cursor, bool throw_notfound);
-    inline move_result(cursor &cursor, move_operation operation,
-                       bool throw_notfound);
-    inline move_result(cursor &cursor, move_operation operation,
-                       const slice &key, bool throw_notfound);
+    move_result(cursor &cursor, move_operation operation, bool throw_notfound)
+        : move_result(cursor, operation, slice::invalid(), slice::invalid(),
+                      throw_notfound) {}
+    move_result(cursor &cursor, move_operation operation, const slice &key,
+                bool throw_notfound)
+        : move_result(cursor, operation, key, slice::invalid(),
+                      throw_notfound) {}
    inline move_result(cursor &cursor, move_operation operation,
                       const slice &key, const slice &value,
                       bool throw_notfound);
@@ -4164,6 +4317,20 @@ public:
    move_result &operator=(const move_result &) noexcept = default;
  };

+  struct estimate_result : public pair {
+    ptrdiff_t approximate_quantity;
+    estimate_result(const cursor &cursor, move_operation operation)
+        : estimate_result(cursor, operation, slice::invalid(),
+                          slice::invalid()) {}
+    estimate_result(const cursor &cursor, move_operation operation,
+                    const slice &key)
+        : estimate_result(cursor, operation, key, slice::invalid()) {}
+    inline estimate_result(const cursor &cursor, move_operation operation,
+                           const slice &key, const slice &value);
+    estimate_result(const estimate_result &) noexcept = default;
+    estimate_result &operator=(const estimate_result &) noexcept = default;
+  };
+
 protected:
  inline bool move(move_operation operation, MDBX_val *key, MDBX_val *value,
                   bool throw_notfound) const
@@ -4208,19 +4375,20 @@ public:
  inline bool eof() const;
  inline bool on_first() const;
  inline bool on_last() const;
-  inline ptrdiff_t estimate(slice key, slice value) const;
-  inline ptrdiff_t estimate(slice key) const;
-  inline ptrdiff_t estimate(move_operation operation) const;
+  inline estimate_result estimate(const slice &key, const slice &value) const;
+  inline estimate_result estimate(const slice &key) const;
+  inline estimate_result estimate(move_operation operation) const;
+  inline estimate_result estimate(move_operation operation, slice &key) const;

  //----------------------------------------------------------------------------

  /// \brief Renew/bind a cursor with a new transaction and previously used
  /// key-value map handle.
-  inline void renew(::mdbx::txn &txn);
+  inline void renew(const ::mdbx::txn &txn);

  /// \brief Bind/renew a cursor with a new transaction and specified key-value
  /// map handle.
-  inline void bind(::mdbx::txn &txn, ::mdbx::map_handle map_handle);
+  inline void bind(const ::mdbx::txn &txn, ::mdbx::map_handle map_handle);

  /// \brief Returns the cursor's transaction.
  inline ::mdbx::txn txn() const;
@@ -4274,7 +4442,8 @@ class LIBMDBX_API_TYPE cursor_managed : public cursor {

 public:
  /// \brief Creates a new managed cursor with underlying object.
-  cursor_managed() : cursor_managed(::mdbx_cursor_create(nullptr)) {
+  cursor_managed(void *your_context = nullptr)
+      : cursor_managed(::mdbx_cursor_create(your_context)) {
    if (MDBX_UNLIKELY(!handle_))
      MDBX_CXX20_UNLIKELY error::throw_exception(MDBX_ENOMEM);
  }
@@ -5416,6 +5585,15 @@ MDBX_CXX11_CONSTEXPR bool operator!=(const txn &a, const txn &b) noexcept {
  return a.handle_ != b.handle_;
 }

+inline void *txn::get_context() const noexcept {
+  return mdbx_txn_get_userctx(handle_);
+}
+
+inline txn &txn::set_context(void *ptr) {
+  error::success_or_throw(::mdbx_txn_set_userctx(handle_, ptr));
+  return *this;
+}
+
 inline bool txn::is_dirty(const void *ptr) const {
  int err = ::mdbx_is_dirty(handle_, ptr);
  switch (err) {
@@ -5456,7 +5634,7 @@ inline txn::info txn::get_info(bool scan_reader_lock_table) const {
  return r;
 }

-inline cursor_managed txn::open_cursor(map_handle map) {
+inline cursor_managed txn::open_cursor(map_handle map) const {
  MDBX_cursor *ptr;
  error::success_or_throw(::mdbx_cursor_open(handle_, map.dbi, &ptr));
  return cursor_managed(ptr);
@@ -5854,28 +6032,32 @@ inline size_t txn::put_multiple(map_handle map, const slice &key,
  return args[1].iov_len /* done item count */;
 }

-inline ptrdiff_t txn::estimate(map_handle map, pair from, pair to) const {
+inline ptrdiff_t txn::estimate(map_handle map, const pair &from,
+                               const pair &to) const {
  ptrdiff_t result;
  error::success_or_throw(mdbx_estimate_range(
      handle_, map.dbi, &from.key, &from.value, &to.key, &to.value, &result));
  return result;
 }

-inline ptrdiff_t txn::estimate(map_handle map, slice from, slice to) const {
+inline ptrdiff_t txn::estimate(map_handle map, const slice &from,
+                               const slice &to) const {
  ptrdiff_t result;
  error::success_or_throw(mdbx_estimate_range(handle_, map.dbi, &from, nullptr,
                                              &to, nullptr, &result));
  return result;
 }

-inline ptrdiff_t txn::estimate_from_first(map_handle map, slice to) const {
+inline ptrdiff_t txn::estimate_from_first(map_handle map,
+                                          const slice &to) const {
  ptrdiff_t result;
  error::success_or_throw(mdbx_estimate_range(handle_, map.dbi, nullptr,
                                              nullptr, &to, nullptr, &result));
  return result;
 }

-inline ptrdiff_t txn::estimate_to_last(map_handle map, slice from) const {
+inline ptrdiff_t txn::estimate_to_last(map_handle map,
+                                       const slice &from) const {
  ptrdiff_t result;
  error::success_or_throw(mdbx_estimate_range(handle_, map.dbi, &from, nullptr,
                                              nullptr, nullptr, &result));
@@ -5886,6 +6068,21 @@ inline ptrdiff_t txn::estimate_to_last(map_handle map, slice from) const {

 MDBX_CXX11_CONSTEXPR cursor::cursor(MDBX_cursor *ptr) noexcept : handle_(ptr) {}

+inline cursor_managed cursor::clone(void *your_context) const {
+  cursor_managed clone(your_context);
+  error::success_or_throw(::mdbx_cursor_copy(handle_, clone.handle_));
+  return clone;
+}
+
+inline void *cursor::get_context() const noexcept {
+  return mdbx_cursor_get_userctx(handle_);
+}
+
+inline cursor &cursor::set_context(void *ptr) {
+  error::success_or_throw(::mdbx_cursor_set_userctx(handle_, ptr));
+  return *this;
+}
+
 inline cursor &cursor::operator=(cursor &&other) noexcept {
  handle_ = other.handle_;
  other.handle_ = nullptr;
@@ -5924,22 +6121,8 @@ MDBX_CXX11_CONSTEXPR bool operator!=(const cursor &a,

 inline cursor::move_result::move_result(const cursor &cursor,
                                        bool throw_notfound)
-    : pair_result(key, value, false) {
-  done = cursor.move(get_current, &key, &value, throw_notfound);
-}
-
-inline cursor::move_result::move_result(cursor &cursor,
-                                        move_operation operation,
-                                        bool throw_notfound)
-    : pair_result(key, value, false) {
-  done = cursor.move(operation, &key, &value, throw_notfound);
-}
-
-inline cursor::move_result::move_result(cursor &cursor,
-                                        move_operation operation,
-                                        const slice &key, bool throw_notfound)
-    : pair_result(key, slice(), false) {
-  this->done = cursor.move(operation, &this->key, &this->value, throw_notfound);
+    : pair_result(slice(), slice(), false) {
+  done = cursor.move(get_current, &this->key, &this->value, throw_notfound);
 }

 inline cursor::move_result::move_result(cursor &cursor,
@@ -5966,6 +6149,14 @@ inline bool cursor::move(move_operation operation, MDBX_val *key,
  }
 }

+inline cursor::estimate_result::estimate_result(const cursor &cursor,
+                                                move_operation operation,
+                                                const slice &key,
+                                                const slice &value)
+    : pair(key, value), approximate_quantity(PTRDIFF_MIN) {
+  approximate_quantity = cursor.estimate(operation, &this->key, &this->value);
+}
+
 inline ptrdiff_t cursor::estimate(move_operation operation, MDBX_val *key,
                                  MDBX_val *value) const {
  ptrdiff_t result;
@@ -6088,24 +6279,26 @@ inline bool cursor::on_last() const {
  return error::boolean_or_throw(::mdbx_cursor_on_last(*this));
 }

-inline ptrdiff_t cursor::estimate(slice key, slice value) const {
-  return estimate(multi_exactkey_lowerboundvalue, &key, &value);
+inline cursor::estimate_result cursor::estimate(const slice &key,
+                                                const slice &value) const {
+  return estimate_result(*this, multi_exactkey_lowerboundvalue, key, value);
 }

-inline ptrdiff_t cursor::estimate(slice key) const {
-  return estimate(key_lowerbound, &key, nullptr);
+inline cursor::estimate_result cursor::estimate(const slice &key) const {
+  return estimate_result(*this, key_lowerbound, key);
 }

-inline ptrdiff_t cursor::estimate(move_operation operation) const {
-  slice unused_key;
-  return estimate(operation, &unused_key, nullptr);
+inline cursor::estimate_result
+cursor::estimate(move_operation operation) const {
+  return estimate_result(*this, operation);
 }

-inline void cursor::renew(::mdbx::txn &txn) {
+inline void cursor::renew(const ::mdbx::txn &txn) {
  error::success_or_throw(::mdbx_cursor_renew(txn, handle_));
 }

-inline void cursor::bind(::mdbx::txn &txn, ::mdbx::map_handle map_handle) {
+inline void cursor::bind(const ::mdbx::txn &txn,
+                         ::mdbx::map_handle map_handle) {
  error::success_or_throw(::mdbx_cursor_bind(txn, handle_, map_handle.dbi));
 }

--- a/packages/buildroot/0001-package-libmdbx-new-package-library-database.patch
+++ b/packages/buildroot/0001-package-libmdbx-new-package-library-database.patch
@@ -1,7 +1,7 @@
-From 790cbdc02c2597650964a564e05fbb5af503adc9 Mon Sep 17 00:00:00 2001
+From 3efdf07a80f750c23de126ac80e78fb0545a1b63 Mon Sep 17 00:00:00 2001
 From: =?UTF-8?q?=D0=9B=D0=B5=D0=BE=D0=BD=D0=B8=D0=B4=20=D0=AE=D1=80=D1=8C?=
 =?UTF-8?q?=D0=B5=D0=B2=20=28Leonid=20Yuriev=29?= <leo@yuriev.ru>
-Date: Wed, 19 Apr 2023 13:34:37 +0300
+Date: Mon, 23 Oct 2023 18:07:13 +0300
 Subject: [PATCH] package/libmdbx: new package (library/database).
 MIME-Version: 1.0
 Content-Type: text/plain; charset=UTF-8
@@ -15,8 +15,9 @@ This patch adds libmdbx:
   in terms of reliability, features and performance.
 - https://gitflic.ru/project/erthink/libmdbx

-The v0.12.5 "Dynamo" is stable release of frontward _libmdbx_ branch with new superior features
-on the day of 100 anniversary of USSR' «Dynamo» sports and fitness society.
+The v0.12.8 "Vladimir Utkin" is stable release of frontward _libmdbx_
+branch with new superior features on the day of 100 anniversary of the birth
+of the outstanding Soviet and Russian scientist and engineer Vladimir Fedorovich Utkin.

 The complete ChangeLog: https://gitflic.ru/project/erthink/libmdbx/blob?file=ChangeLog.md

@@ -111,18 +112,18 @@ index 0000000000..a9a4ac45c5
 +		!BR2_TOOLCHAIN_GCC_AT_LEAST_4_4
 diff --git a/package/libmdbx/libmdbx.hash b/package/libmdbx/libmdbx.hash
 new file mode 100644
-index 0000000000..7a5b19952e
+index 0000000000..82cf28d6a9
 --- /dev/null
 +++ b/package/libmdbx/libmdbx.hash
@@ -0,0 +1,5 @@
 +# Hashes from: https://libmdbx.dqdkfa.ru/release/SHA256SUMS
-+sha256  9c3abaaf9079a9518bb7155734817a2e286fffea46f7cc0825dfbd1cf9174075  libmdbx-amalgamated-0.12.5.tar.xz
+sha256  c78c56c53708bbfc519bf53ebf520d1f09d30ee6427a4bedf713316696e671d0  libmdbx-amalgamated-0.12.8.tar.xz
 +
 +# Locally calculated
 +sha256  310fe25c858a9515fc8c8d7d1f24a67c9496f84a91e0a0e41ea9975b1371e569  LICENSE
 diff --git a/package/libmdbx/libmdbx.mk b/package/libmdbx/libmdbx.mk
 new file mode 100644
-index 0000000000..9a196eda60
+index 0000000000..d198fe5b22
 --- /dev/null
 +++ b/package/libmdbx/libmdbx.mk
@@ -0,0 +1,42 @@
@@ -132,7 +133,7 @@ index 0000000000..9a196eda60
 +#
 +################################################################################
 +
-+LIBMDBX_VERSION = 0.12.5
+LIBMDBX_VERSION = 0.12.8
 +LIBMDBX_SOURCE = libmdbx-amalgamated-$(LIBMDBX_VERSION).tar.xz
 +LIBMDBX_SITE = https://libmdbx.dqdkfa.ru/release
 +LIBMDBX_SUPPORTS_IN_SOURCE_BUILD = NO
@@ -169,5 +170,5 @@ index 0000000000..9a196eda60
 +
 +$(eval $(cmake-package))
 -- 
-2.34.1
+2.42.0

--- a/src/alloy.c
+++ b/src/alloy.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2015-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/src/base.h
+++ b/src/base.h
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2015-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/src/core.c
+++ b/src/core.c
--- a/src/internals.h
+++ b/src/internals.h
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2015-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
@@ -1376,8 +1376,12 @@ struct MDBX_env {
  struct MDBX_lockinfo *me_lck;

  unsigned me_psize;          /* DB page size, initialized from me_os_psize */
-  unsigned me_leaf_nodemax;   /* max size of a leaf-node */
-  unsigned me_branch_nodemax; /* max size of a branch-node */
+  uint16_t me_leaf_nodemax;   /* max size of a leaf-node */
+  uint16_t me_branch_nodemax; /* max size of a branch-node */
+  uint16_t me_subpage_limit;
+  uint16_t me_subpage_room_threshold;
+  uint16_t me_subpage_reserve_prereq;
+  uint16_t me_subpage_reserve_limit;
  atomic_pgno_t me_mlocked_pgno;
  uint8_t me_psize2log; /* log2 of DB page size */
  int8_t me_stuck_meta; /* recovery-only: target meta page or less that zero */
--- a/src/lck-posix.c
+++ b/src/lck-posix.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2015-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/src/lck-windows.c
+++ b/src/lck-windows.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2015-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/src/man1/mdbx_chk.1
+++ b/src/man1/mdbx_chk.1
@@ -1,6 +1,6 @@
-.\" Copyright 2015-2023 Leonid Yuriev <leo@yuriev.ru>.
+.\" Copyright 2015-2024 Leonid Yuriev <leo@yuriev.ru>.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.TH MDBX_CHK 1 "2023-10-17" "MDBX 0.12.8"
+.TH MDBX_CHK 1 "2024-03-13" "MDBX 0.12.10"
 .SH NAME
 mdbx_chk \- MDBX checking tool
 .SH SYNOPSIS
--- a/src/man1/mdbx_copy.1
+++ b/src/man1/mdbx_copy.1
@@ -1,8 +1,8 @@
-.\" Copyright 2015-2023 Leonid Yuriev <leo@yuriev.ru>.
+.\" Copyright 2015-2024 Leonid Yuriev <leo@yuriev.ru>.
 .\" Copyright 2015,2016 Peter-Service R&D LLC <http://billing.ru/>.
 .\" Copyright 2012-2015 Howard Chu, Symas Corp. All Rights Reserved.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.TH MDBX_COPY 1 "2023-10-17" "MDBX 0.12.8"
+.TH MDBX_COPY 1 "2024-03-13" "MDBX 0.12.10"
 .SH NAME
 mdbx_copy \- MDBX environment copy tool
 .SH SYNOPSIS
--- a/src/man1/mdbx_drop.1
+++ b/src/man1/mdbx_drop.1
@@ -1,7 +1,7 @@
-.\" Copyright 2021-2023 Leonid Yuriev <leo@yuriev.ru>.
+.\" Copyright 2021-2024 Leonid Yuriev <leo@yuriev.ru>.
 .\" Copyright 2014-2021 Howard Chu, Symas Corp. All Rights Reserved.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.TH MDBX_DROP 1 "2023-10-17" "MDBX 0.12.8"
+.TH MDBX_DROP 1 "2024-03-13" "MDBX 0.12.10"
 .SH NAME
 mdbx_drop \- MDBX database delete tool
 .SH SYNOPSIS
--- a/src/man1/mdbx_dump.1
+++ b/src/man1/mdbx_dump.1
@@ -1,8 +1,8 @@
-.\" Copyright 2015-2023 Leonid Yuriev <leo@yuriev.ru>.
+.\" Copyright 2015-2024 Leonid Yuriev <leo@yuriev.ru>.
 .\" Copyright 2015,2016 Peter-Service R&D LLC <http://billing.ru/>.
 .\" Copyright 2014-2015 Howard Chu, Symas Corp. All Rights Reserved.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.TH MDBX_DUMP 1 "2023-10-17" "MDBX 0.12.8"
+.TH MDBX_DUMP 1 "2024-03-13" "MDBX 0.12.10"
 .SH NAME
 mdbx_dump \- MDBX environment export tool
 .SH SYNOPSIS
--- a/src/man1/mdbx_load.1
+++ b/src/man1/mdbx_load.1
@@ -1,8 +1,8 @@
-.\" Copyright 2015-2023 Leonid Yuriev <leo@yuriev.ru>.
+.\" Copyright 2015-2024 Leonid Yuriev <leo@yuriev.ru>.
 .\" Copyright 2015,2016 Peter-Service R&D LLC <http://billing.ru/>.
 .\" Copyright 2014-2015 Howard Chu, Symas Corp. All Rights Reserved.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.TH MDBX_LOAD 1 "2023-10-17" "MDBX 0.12.8"
+.TH MDBX_LOAD 1 "2024-03-13" "MDBX 0.12.10"
 .SH NAME
 mdbx_load \- MDBX environment import tool
 .SH SYNOPSIS
--- a/src/man1/mdbx_stat.1
+++ b/src/man1/mdbx_stat.1
@@ -1,8 +1,8 @@
-.\" Copyright 2015-2023 Leonid Yuriev <leo@yuriev.ru>.
+.\" Copyright 2015-2024 Leonid Yuriev <leo@yuriev.ru>.
 .\" Copyright 2015,2016 Peter-Service R&D LLC <http://billing.ru/>.
 .\" Copyright 2012-2015 Howard Chu, Symas Corp. All Rights Reserved.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.TH MDBX_STAT 1 "2023-10-17" "MDBX 0.12.8"
+.TH MDBX_STAT 1 "2024-03-13" "MDBX 0.12.10"
 .SH NAME
 mdbx_stat \- MDBX environment status tool
 .SH SYNOPSIS
--- a/src/mdbx.c++
+++ b/src/mdbx.c++
@@ -1,5 +1,5 @@
 //
-// Copyright (c) 2020-2023, Leonid Yuriev <leo@yuriev.ru>.
+// Copyright (c) 2020-2024, Leonid Yuriev <leo@yuriev.ru>.
 // SPDX-License-Identifier: Apache-2.0
 //
 // Non-inline part of the libmdbx C++ API
@@ -207,6 +207,44 @@ __cold  bug::~bug() noexcept {}

 #endif /* Unused*/

+struct line_wrapper {
+  char *line, *ptr;
+  line_wrapper(char *buf) noexcept : line(buf), ptr(buf) {}
+  void put(char c, size_t wrap_width) noexcept {
+    *ptr++ = c;
+    if (wrap_width && ptr >= wrap_width + line) {
+      *ptr++ = '\n';
+      line = ptr;
+    }
+  }
+  void put(const ::mdbx::slice &chunk, size_t wrap_width) noexcept {
+    if (!wrap_width || wrap_width > (ptr - line) + chunk.length()) {
+      memcpy(ptr, chunk.data(), chunk.length());
+      ptr += chunk.length();
+    } else {
+      for (size_t i = 0; i < chunk.length(); ++i)
+        put(chunk.char_ptr()[i], wrap_width);
+    }
+  }
+};
+
+template <typename TYPE, unsigned INPLACE_BYTES = unsigned(sizeof(void *) * 64)>
+struct temp_buffer {
+  TYPE inplace[(INPLACE_BYTES + sizeof(TYPE) - 1) / sizeof(TYPE)];
+  const size_t size;
+  TYPE *const area;
+  temp_buffer(size_t bytes)
+      : size((bytes + sizeof(TYPE) - 1) / sizeof(TYPE)),
+        area((bytes > sizeof(inplace)) ? new TYPE[size] : inplace) {
+    memset(area, 0, sizeof(TYPE) * size);
+  }
+  ~temp_buffer() {
+    if (area != inplace)
+      delete[] area;
+  }
+  TYPE *end() const { return area + size; }
+};
+
 } // namespace

 //------------------------------------------------------------------------------
@@ -285,7 +323,7 @@ DEFINE_EXCEPTION(something_busy)
 DEFINE_EXCEPTION(thread_mismatch)
 DEFINE_EXCEPTION(transaction_full)
 DEFINE_EXCEPTION(transaction_overlapping)
-
+DEFINE_EXCEPTION(duplicated_lck_file)
 #undef DEFINE_EXCEPTION

 __cold const char *error::what() const noexcept {
@@ -371,6 +409,7 @@ __cold void error::throw_exception() const {
    CASE_EXCEPTION(thread_mismatch, MDBX_THREAD_MISMATCH);
    CASE_EXCEPTION(transaction_full, MDBX_TXN_FULL);
    CASE_EXCEPTION(transaction_overlapping, MDBX_TXN_OVERLAPPING);
+    CASE_EXCEPTION(duplicated_lck_file, MDBX_DUPLICATED_CLK);
 #undef CASE_EXCEPTION
  default:
    if (is_mdbx_error())
@@ -598,7 +637,7 @@ char *to_hex::write_bytes(char *__restrict const dest, size_t dest_size) const {

  auto ptr = dest;
  auto src = source.byte_ptr();
-  const char alphabase = (uppercase ? 'A' : 'a') - 10;
+  const char alpha_shift = (uppercase ? 'A' : 'a') - '9' - 1;
  auto line = ptr;
  for (const auto end = source.end_byte_ptr(); src != end; ++src) {
    if (wrap_width && size_t(ptr - line) >= wrap_width) {
@@ -607,8 +646,8 @@ char *to_hex::write_bytes(char *__restrict const dest, size_t dest_size) const {
    }
    const int8_t hi = *src >> 4;
    const int8_t lo = *src & 15;
-    ptr[0] = char(alphabase + hi + (((hi - 10) >> 7) & -7));
-    ptr[1] = char(alphabase + lo + (((lo - 10) >> 7) & -7));
+    ptr[0] = char('0' + hi + (((9 - hi) >> 7) & alpha_shift));
+    ptr[1] = char('0' + lo + (((9 - lo) >> 7) & alpha_shift));
    ptr += 2;
    assert(ptr <= dest + dest_size);
  }
@@ -620,7 +659,7 @@ char *to_hex::write_bytes(char *__restrict const dest, size_t dest_size) const {
    MDBX_CXX20_LIKELY {
      ::std::ostream::sentry sentry(out);
      auto src = source.byte_ptr();
-      const char alphabase = (uppercase ? 'A' : 'a') - 10;
+      const char alpha_shift = (uppercase ? 'A' : 'a') - '9' - 1;
      unsigned width = 0;
      for (const auto end = source.end_byte_ptr(); src != end; ++src) {
        if (wrap_width && width >= wrap_width) {
@@ -629,8 +668,8 @@ char *to_hex::write_bytes(char *__restrict const dest, size_t dest_size) const {
        }
        const int8_t hi = *src >> 4;
        const int8_t lo = *src & 15;
-        out.put(char(alphabase + hi + (((hi - 10) >> 7) & -7)));
-        out.put(char(alphabase + lo + (((lo - 10) >> 7) & -7)));
+        out.put(char('0' + hi + (((9 - hi) >> 7) & alpha_shift)));
+        out.put(char('0' + lo + (((9 - lo) >> 7) & alpha_shift)));
        width += 2;
      }
    }
@@ -661,11 +700,11 @@ char *from_hex::write_bytes(char *__restrict const dest,

    int8_t hi = src[0];
    hi = (hi | 0x20) - 'a';
-    hi += 10 + ((hi >> 7) & 7);
+    hi += 10 + ((hi >> 7) & 39);

    int8_t lo = src[1];
    lo = (lo | 0x20) - 'a';
-    lo += 10 + ((lo >> 7) & 7);
+    lo += 10 + ((lo >> 7) & 39);

    *ptr++ = hi << 4 | lo;
    src += 2;
@@ -708,156 +747,135 @@ enum : signed char {
  IL /* invalid */ = -1
 };

-static const byte b58_alphabet[58] = {
-    '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F',
-    'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
-    'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'm',
-    'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'};
-
-#ifndef bswap64
-#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
-static inline uint64_t bswap64(uint64_t v) noexcept {
-#if __GNUC_PREREQ(4, 4) || __CLANG_PREREQ(4, 0) ||                             \
-    __has_builtin(__builtin_bswap64)
-  return __builtin_bswap64(v);
-#elif defined(_MSC_VER) && !defined(__clang__)
-  return _byteswap_uint64(v);
-#elif defined(__bswap_64)
-  return __bswap_64(v);
-#elif defined(bswap_64)
-  return bswap_64(v);
+#if MDBX_WORDBITS > 32
+using b58_uint = uint_fast64_t;
 #else
-  return v << 56 | v >> 56 | ((v << 40) & UINT64_C(0x00ff000000000000)) |
-         ((v << 24) & UINT64_C(0x0000ff0000000000)) |
-         ((v << 8) & UINT64_C(0x000000ff00000000)) |
-         ((v >> 8) & UINT64_C(0x00000000ff000000)) |
-         ((v >> 24) & UINT64_C(0x0000000000ff0000)) |
-         ((v >> 40) & UINT64_C(0x000000000000ff00));
+using b58_uint = uint_fast32_t;
 #endif
-}
-#endif /* __BYTE_ORDER__ */
-#endif /* ifndef bswap64 */

-static inline char b58_8to11(uint64_t &v) noexcept {
-  const unsigned i = unsigned(v % 58);
+struct b58_buffer : public temp_buffer<b58_uint> {
+  b58_buffer(size_t bytes, size_t estimation_ratio_numerator,
+             size_t estimation_ratio_denominator, size_t extra = 0)
+      : temp_buffer((/* пересчитываем по указанной пропорции */
+                     bytes = (bytes * estimation_ratio_numerator +
+                              estimation_ratio_denominator - 1) /
+                             estimation_ratio_denominator,
+                     /* учитываем резервный старший байт в каждом слове */
+                     ((bytes + sizeof(b58_uint) - 2) / (sizeof(b58_uint) - 1) *
+                          sizeof(b58_uint) +
+                      extra) *
+                         sizeof(b58_uint))) {}
+};
+
+static byte b58_8to11(b58_uint &v) noexcept {
+  static const char b58_alphabet[58] = {
+      '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F',
+      'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
+      'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'm',
+      'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'};
+
+  const auto i = size_t(v % 58);
  v /= 58;
  return b58_alphabet[i];
 }

+static slice b58_encode(b58_buffer &buf, const byte *begin, const byte *end) {
+  auto high = buf.end();
+  const auto modulo =
+      b58_uint((sizeof(b58_uint) > 4) ? UINT64_C(0x1A636A90B07A00) /* 58^9 */
+                                      : UINT32_C(0xACAD10) /* 58^4 */);
+  static_assert(sizeof(modulo) == 4 || sizeof(modulo) == 8, "WTF?");
+  while (begin < end) {
+    b58_uint carry = *begin++;
+    auto ptr = buf.end();
+    do {
+      assert(ptr > buf.area);
+      carry += *--ptr << CHAR_BIT;
+      *ptr = carry % modulo;
+      carry /= modulo;
+    } while (carry || ptr > high);
+    high = ptr;
+  }
+
+  byte *output = static_cast<byte *>(static_cast<void *>(buf.area));
+  auto ptr = output;
+  for (auto porous = high; porous < buf.end();) {
+    auto chunk = *porous++;
+    static_assert(sizeof(chunk) == 4 || sizeof(chunk) == 8, "WTF?");
+    assert(chunk < modulo);
+    if (sizeof(chunk) > 4) {
+      ptr[8] = b58_8to11(chunk);
+      ptr[7] = b58_8to11(chunk);
+      ptr[6] = b58_8to11(chunk);
+      ptr[5] = b58_8to11(chunk);
+      ptr[4] = b58_8to11(chunk);
+      ptr[3] = b58_8to11(chunk);
+      ptr[2] = b58_8to11(chunk);
+      ptr[1] = b58_8to11(chunk);
+      ptr[0] = b58_8to11(chunk);
+      ptr += 9;
+    } else {
+      ptr[3] = b58_8to11(chunk);
+      ptr[2] = b58_8to11(chunk);
+      ptr[1] = b58_8to11(chunk);
+      ptr[0] = b58_8to11(chunk);
+      ptr += 4;
+    }
+    assert(static_cast<void *>(ptr) < static_cast<void *>(porous));
+  }
+
+  while (output < ptr && *output == '1')
+    ++output;
+  return slice(output, ptr);
+}
+
 char *to_base58::write_bytes(char *__restrict const dest,
                             size_t dest_size) const {
  if (MDBX_UNLIKELY(envisage_result_length() > dest_size))
    MDBX_CXX20_UNLIKELY throw_too_small_target_buffer();

-  auto ptr = dest;
-  auto src = source.byte_ptr();
-  size_t left = source.length();
-  auto line = ptr;
-  while (MDBX_LIKELY(left > 7)) {
-    uint64_t v;
-    std::memcpy(&v, src, 8);
-    src += 8;
-#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
-    v = bswap64(v);
-#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
-#else
-#error "FIXME: Unsupported byte order"
-#endif /* __BYTE_ORDER__ */
-    ptr[10] = b58_8to11(v);
-    ptr[9] = b58_8to11(v);
-    ptr[8] = b58_8to11(v);
-    ptr[7] = b58_8to11(v);
-    ptr[6] = b58_8to11(v);
-    ptr[5] = b58_8to11(v);
-    ptr[4] = b58_8to11(v);
-    ptr[3] = b58_8to11(v);
-    ptr[2] = b58_8to11(v);
-    ptr[1] = b58_8to11(v);
-    ptr[0] = b58_8to11(v);
-    assert(v == 0);
-    ptr += 11;
-    left -= 8;
-    if (wrap_width && size_t(ptr - line) >= wrap_width && left) {
-      *ptr = '\n';
-      line = ++ptr;
-    }
-    assert(ptr <= dest + dest_size);
+  auto begin = source.byte_ptr();
+  auto end = source.end_byte_ptr();
+  line_wrapper wrapper(dest);
+  while (MDBX_LIKELY(begin < end) && *begin == 0) {
+    wrapper.put('1', wrap_width);
+    assert(wrapper.ptr <= dest + dest_size);
+    ++begin;
  }

-  if (left) {
-    uint64_t v = 0;
-    unsigned parrots = 31;
-    do {
-      v = (v << 8) + *src++;
-      parrots += 43;
-    } while (--left);
-
-    auto tail = ptr += parrots >> 5;
-    assert(ptr <= dest + dest_size);
-    do {
-      *--tail = b58_8to11(v);
-      parrots -= 32;
-    } while (parrots > 31);
-    assert(v == 0);
-  }
-
-  return ptr;
+  b58_buffer buf(end - begin, 11, 8);
+  wrapper.put(b58_encode(buf, begin, end), wrap_width);
+  return wrapper.ptr;
 }

 ::std::ostream &to_base58::output(::std::ostream &out) const {
  if (MDBX_LIKELY(!is_empty()))
    MDBX_CXX20_LIKELY {
      ::std::ostream::sentry sentry(out);
-      auto src = source.byte_ptr();
-      size_t left = source.length();
+      auto begin = source.byte_ptr();
+      auto end = source.end_byte_ptr();
      unsigned width = 0;
-      std::array<char, 11> buf;
-
-      while (MDBX_LIKELY(left > 7)) {
-        uint64_t v;
-        std::memcpy(&v, src, 8);
-        src += 8;
-#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
-        v = bswap64(v);
-#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
-#else
-#error "FIXME: Unsupported byte order"
-#endif /* __BYTE_ORDER__ */
-        buf[10] = b58_8to11(v);
-        buf[9] = b58_8to11(v);
-        buf[8] = b58_8to11(v);
-        buf[7] = b58_8to11(v);
-        buf[6] = b58_8to11(v);
-        buf[5] = b58_8to11(v);
-        buf[4] = b58_8to11(v);
-        buf[3] = b58_8to11(v);
-        buf[2] = b58_8to11(v);
-        buf[1] = b58_8to11(v);
-        buf[0] = b58_8to11(v);
-        assert(v == 0);
-        out.write(&buf.front(), 11);
-        left -= 8;
-        if (wrap_width && (width += 11) >= wrap_width && left) {
+      while (MDBX_LIKELY(begin < end) && *begin == 0) {
+        out.put('1');
+        if (wrap_width && ++width >= wrap_width) {
          out << ::std::endl;
          width = 0;
        }
+        ++begin;
      }

-      if (left) {
-        uint64_t v = 0;
-        unsigned parrots = 31;
-        do {
-          v = (v << 8) + *src++;
-          parrots += 43;
-        } while (--left);
-
-        auto ptr = buf.end();
-        do {
-          *--ptr = b58_8to11(v);
-          parrots -= 32;
-        } while (parrots > 31);
-        assert(v == 0);
-        out.write(&*ptr, buf.end() - ptr);
+      b58_buffer buf(end - begin, 11, 8);
+      const auto chunk = b58_encode(buf, begin, end);
+      if (!wrap_width || wrap_width > width + chunk.length())
+        out.write(chunk.char_ptr(), chunk.length());
+      else {
+        for (size_t i = 0; i < chunk.length(); ++i) {
+          out.put(chunk.char_ptr()[i]);
+          if (wrap_width && ++width >= wrap_width) {
+            out << ::std::endl;
+            width = 0;
+          }
+        }
      }
    }
  return out;
@@ -883,10 +901,46 @@ const signed char b58_map[256] = {
    IL, IL, IL, IL, IL, IL, IL, IL, IL, IL, IL, IL, IL, IL, IL, IL  // f0
 };

-static inline signed char b58_11to8(uint64_t &v, const byte c) noexcept {
-  const signed char m = b58_map[c];
-  v = v * 58 + m;
-  return m;
+static slice b58_decode(b58_buffer &buf, const byte *begin, const byte *end,
+                        bool ignore_spaces) {
+  auto high = buf.end();
+  while (begin < end) {
+    const auto c = b58_map[*begin++];
+    if (MDBX_LIKELY(c >= 0)) {
+      b58_uint carry = c;
+      auto ptr = buf.end();
+      do {
+        assert(ptr > buf.area);
+        carry += *--ptr * 58;
+        *ptr = carry & (~b58_uint(0) >> CHAR_BIT);
+        carry >>= CHAR_BIT * (sizeof(carry) - 1);
+      } while (carry || ptr > high);
+      high = ptr;
+    } else if (MDBX_UNLIKELY(!ignore_spaces || !isspace(begin[-1])))
+      MDBX_CXX20_UNLIKELY
+    throw std::domain_error("mdbx::from_base58:: invalid base58 string");
+  }
+
+  byte *output = static_cast<byte *>(static_cast<void *>(buf.area));
+  auto ptr = output;
+  for (auto porous = high; porous < buf.end(); ++porous) {
+    auto chunk = *porous;
+    static_assert(sizeof(chunk) == 4 || sizeof(chunk) == 8, "WTF?");
+    assert(chunk <= (~b58_uint(0) >> CHAR_BIT));
+    if (sizeof(chunk) > 4) {
+      *ptr++ = byte(uint_fast64_t(chunk) >> CHAR_BIT * 6);
+      *ptr++ = byte(uint_fast64_t(chunk) >> CHAR_BIT * 5);
+      *ptr++ = byte(uint_fast64_t(chunk) >> CHAR_BIT * 4);
+      *ptr++ = byte(chunk >> CHAR_BIT * 3);
+    }
+    *ptr++ = byte(chunk >> CHAR_BIT * 2);
+    *ptr++ = byte(chunk >> CHAR_BIT * 1);
+    *ptr++ = byte(chunk >> CHAR_BIT * 0);
+  }
+
+  while (output < ptr && *output == 0)
+    ++output;
+  return slice(output, ptr);
 }

 char *from_base58::write_bytes(char *__restrict const dest,
@@ -895,98 +949,33 @@ char *from_base58::write_bytes(char *__restrict const dest,
    MDBX_CXX20_UNLIKELY throw_too_small_target_buffer();

  auto ptr = dest;
-  auto src = source.byte_ptr();
-  for (auto left = source.length(); left > 0;) {
-    if (MDBX_UNLIKELY(isspace(*src)) && ignore_spaces) {
-      ++src;
-      --left;
-      continue;
-    }
-
-    if (MDBX_LIKELY(left > 10)) {
-      uint64_t v = 0;
-      if (MDBX_UNLIKELY((b58_11to8(v, src[0]) | b58_11to8(v, src[1]) |
-                         b58_11to8(v, src[2]) | b58_11to8(v, src[3]) |
-                         b58_11to8(v, src[4]) | b58_11to8(v, src[5]) |
-                         b58_11to8(v, src[6]) | b58_11to8(v, src[7]) |
-                         b58_11to8(v, src[8]) | b58_11to8(v, src[9]) |
-                         b58_11to8(v, src[10])) < 0))
-        MDBX_CXX20_UNLIKELY goto bailout;
-#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
-      v = bswap64(v);
-#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
-#else
-#error "FIXME: Unsupported byte order"
-#endif /* __BYTE_ORDER__ */
-      std::memcpy(ptr, &v, 8);
-      ptr += 8;
-      src += 11;
-      left -= 11;
-      assert(ptr <= dest + dest_size);
-      continue;
-    }
-
-    constexpr unsigned invalid_length_mask = 1 << 1 | 1 << 4 | 1 << 8;
-    if (MDBX_UNLIKELY(invalid_length_mask & (1 << left)))
-      MDBX_CXX20_UNLIKELY goto bailout;
-
-    uint64_t v = 1;
-    unsigned parrots = 0;
-    do {
-      if (MDBX_UNLIKELY(b58_11to8(v, *src++) < 0))
-        MDBX_CXX20_UNLIKELY goto bailout;
-      parrots += 32;
-    } while (--left);
-
-    auto tail = ptr += parrots / 43;
-    assert(ptr <= dest + dest_size);
-    do {
-      *--tail = byte(v);
-      v >>= 8;
-    } while (v > 255);
-    break;
+  auto begin = source.byte_ptr();
+  auto const end = source.end_byte_ptr();
+  while (begin < end && *begin <= '1') {
+    if (MDBX_LIKELY(*begin == '1'))
+      MDBX_CXX20_LIKELY *ptr++ = 0;
+    else if (MDBX_UNLIKELY(!ignore_spaces || !isspace(*begin)))
+      MDBX_CXX20_UNLIKELY
+    throw std::domain_error("mdbx::from_base58:: invalid base58 string");
+    ++begin;
  }
-  return ptr;

-bailout:
-  throw std::domain_error("mdbx::from_base58:: invalid base58 string");
+  b58_buffer buf(end - begin, 47, 64);
+  auto slice = b58_decode(buf, begin, end, ignore_spaces);
+  memcpy(ptr, slice.data(), slice.length());
+  return ptr + slice.length();
 }

 bool from_base58::is_erroneous() const noexcept {
-  bool got = false;
-  auto src = source.byte_ptr();
-  for (auto left = source.length(); left > 0;) {
-    if (MDBX_UNLIKELY(*src <= ' ') &&
-        MDBX_LIKELY(ignore_spaces && isspace(*src))) {
-      ++src;
-      --left;
-      continue;
-    }
-
-    if (MDBX_LIKELY(left > 10)) {
-      if (MDBX_UNLIKELY((b58_map[src[0]] | b58_map[src[1]] | b58_map[src[2]] |
-                         b58_map[src[3]] | b58_map[src[4]] | b58_map[src[5]] |
-                         b58_map[src[6]] | b58_map[src[7]] | b58_map[src[8]] |
-                         b58_map[src[9]] | b58_map[src[10]]) < 0))
-        MDBX_CXX20_UNLIKELY return true;
-      src += 11;
-      left -= 11;
-      got = true;
-      continue;
-    }
-
-    constexpr unsigned invalid_length_mask = 1 << 1 | 1 << 4 | 1 << 8;
-    if (invalid_length_mask & (1 << left))
-      return false;
-
-    do
-      if (MDBX_UNLIKELY(b58_map[*src++] < 0))
-        MDBX_CXX20_UNLIKELY return true;
-    while (--left);
-    got = true;
-    break;
+  auto begin = source.byte_ptr();
+  auto const end = source.end_byte_ptr();
+  while (begin < end) {
+    if (MDBX_UNLIKELY(b58_map[*begin] < 0 &&
+                      !(ignore_spaces && isspace(*begin))))
+      return true;
+    ++begin;
  }
-  return !got;
+  return false;
 }

 //------------------------------------------------------------------------------
--- a/src/mdbx_chk.c
+++ b/src/mdbx_chk.c
@@ -1,7 +1,7 @@
 /* mdbx_chk.c - memory-mapped database check tool */

 /*
- * Copyright 2015-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2015-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
@@ -537,26 +537,14 @@ static int pgvisitor(const uint64_t pgno, const unsigned pgnumber,
      data_tree_problems += !is_gc_tree;
      gc_tree_problems += is_gc_tree;
    }
-    if (payload_bytes < 1) {
-      if (nentries > 1) {
-        problem_add("page", pgno, "zero size-of-entry",
-                    "%s-page: payload %" PRIuPTR " bytes, %" PRIuPTR " entries",
-                    pagetype_caption, payload_bytes, nentries);
-        /* if ((size_t)header_bytes + unused_bytes < page_size) {
-          // LY: hush a misuse error
-          page_bytes = page_size;
-        } */
-        data_tree_problems += !is_gc_tree;
-        gc_tree_problems += is_gc_tree;
-      } else {
-        problem_add("page", pgno, "empty",
-                    "%s-page: payload %" PRIuPTR " bytes, %" PRIuPTR
-                    " entries, deep %i",
-                    pagetype_caption, payload_bytes, nentries, deep);
-        dbi->pages.empty += 1;
-        data_tree_problems += !is_gc_tree;
-        gc_tree_problems += is_gc_tree;
-      }
+    if (nentries < 1 || (pagetype == MDBX_page_branch && nentries < 2)) {
+      problem_add("page", pgno, nentries ? "half-empty" : "empty",
+                  "%s-page: payload %" PRIuPTR " bytes, %" PRIuPTR
+                  " entries, deep %i",
+                  pagetype_caption, payload_bytes, nentries, deep);
+      dbi->pages.empty += 1;
+      data_tree_problems += !is_gc_tree;
+      gc_tree_problems += is_gc_tree;
    }

    if (pgnumber) {
@@ -611,7 +599,7 @@ static int handle_freedb(const uint64_t record_number, const MDBX_val *key,
        problem_add("entry", txnid, "wrong idl size", "%" PRIuPTR,
                    data->iov_len);
      size_t number = (data->iov_len >= sizeof(pgno_t)) ? *iptr++ : 0;
-      if (number < 1 || number > MDBX_PGL_LIMIT)
+      if (number > MDBX_PGL_LIMIT)
        problem_add("entry", txnid, "wrong idl length", "%" PRIuPTR, number);
      else if ((number + 1) * sizeof(pgno_t) > data->iov_len) {
        problem_add("entry", txnid, "trimmed idl",
--- a/src/mdbx_copy.c
+++ b/src/mdbx_copy.c
@@ -1,7 +1,7 @@
 /* mdbx_copy.c - memory-mapped database backup tool */

 /*
- * Copyright 2015-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2015-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/src/mdbx_drop.c
+++ b/src/mdbx_drop.c
@@ -1,7 +1,7 @@
 /* mdbx_drop.c - memory-mapped database delete tool */

 /*
- * Copyright 2021-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2021-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 *
 * Copyright 2016-2021 Howard Chu, Symas Corp.
--- a/src/mdbx_dump.c
+++ b/src/mdbx_dump.c
@@ -1,7 +1,7 @@
 /* mdbx_dump.c - memory-mapped database dump tool */

 /*
- * Copyright 2015-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2015-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/src/mdbx_load.c
+++ b/src/mdbx_load.c
@@ -1,7 +1,7 @@
 /* mdbx_load.c - memory-mapped database load tool */

 /*
- * Copyright 2015-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2015-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/src/mdbx_stat.c
+++ b/src/mdbx_stat.c
@@ -1,7 +1,7 @@
 /* mdbx_stat.c - memory-mapped database status tool */

 /*
- * Copyright 2015-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2015-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/src/options.h
+++ b/src/options.h
@@ -28,9 +28,17 @@
 #define MDBX_OSX_SPEED_INSTEADOF_DURABILITY MDBX_OSX_WANNA_DURABILITY
 #endif /* MDBX_OSX_SPEED_INSTEADOF_DURABILITY */

+/** Controls using of POSIX' madvise() and/or similar hints. */
+#ifndef MDBX_ENABLE_MADVISE
+#define MDBX_ENABLE_MADVISE 1
+#elif !(MDBX_ENABLE_MADVISE == 0 || MDBX_ENABLE_MADVISE == 1)
+#error MDBX_ENABLE_MADVISE must be defined as 0 or 1
+#endif /* MDBX_ENABLE_MADVISE */
+
 /** Controls checking PID against reuse DB environment after the fork() */
 #ifndef MDBX_ENV_CHECKPID
-#if defined(MADV_DONTFORK) || defined(_WIN32) || defined(_WIN64)
+#if (defined(MADV_DONTFORK) && MDBX_ENABLE_MADVISE) || defined(_WIN32) ||      \
+    defined(_WIN64)
 /* PID check could be omitted:
 *  - on Linux when madvise(MADV_DONTFORK) is available, i.e. after the fork()
 *    mapped pages will not be available for child process.
@@ -96,8 +104,7 @@
 /** Controls using Unix' mincore() to determine whether DB-pages
 * are resident in memory. */
 #ifndef MDBX_ENABLE_MINCORE
-#if MDBX_ENABLE_PREFAULT &&                                                    \
-    (defined(MINCORE_INCORE) || !(defined(_WIN32) || defined(_WIN64)))
+#if defined(MINCORE_INCORE) || !(defined(_WIN32) || defined(_WIN64))
 #define MDBX_ENABLE_MINCORE 1
 #else
 #define MDBX_ENABLE_MINCORE 0
@@ -118,13 +125,6 @@
 #error MDBX_ENABLE_BIGFOOT must be defined as 0 or 1
 #endif /* MDBX_ENABLE_BIGFOOT */

-/** Controls using of POSIX' madvise() and/or similar hints. */
-#ifndef MDBX_ENABLE_MADVISE
-#define MDBX_ENABLE_MADVISE 1
-#elif !(MDBX_ENABLE_MADVISE == 0 || MDBX_ENABLE_MADVISE == 1)
-#error MDBX_ENABLE_MADVISE must be defined as 0 or 1
-#endif /* MDBX_ENABLE_MADVISE */
-
 /** Disable some checks to reduce an overhead and detection probability of
 * database corruption to a values closer to the LMDB. */
 #ifndef MDBX_DISABLE_VALIDATION
--- a/src/osal.c
+++ b/src/osal.c
@@ -1,7 +1,7 @@
 /* https://en.wikipedia.org/wiki/Operating_system_abstraction_layer */

 /*
- * Copyright 2015-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2015-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
@@ -1826,8 +1826,8 @@ MDBX_INTERNAL_FUNC int osal_check_fs_rdonly(mdbx_filehandle_t handle,
 #else
  struct statvfs info;
  if (err != MDBX_ENOFILE) {
-    if (statvfs(pathname, &info) == 0 && (info.f_flag & ST_RDONLY) == 0)
-      return err;
+    if (statvfs(pathname, &info) == 0)
+      return (info.f_flag & ST_RDONLY) ? MDBX_SUCCESS : err;
    if (errno != MDBX_ENOFILE)
      return errno;
  }
@@ -2571,7 +2571,7 @@ retry_mapview:;
          ptr_disp(map->base, size),
          ((map->current < map->limit) ? map->current : map->limit) - size);
    }
-    map->current = size;
+    map->current = (size < map->limit) ? size : map->limit;
  }

  if (limit == map->limit)
@@ -2732,6 +2732,7 @@ retry_mapview:;
    map->base = ptr;
  }
  map->limit = limit;
+  map->current = size;

 #if MDBX_ENABLE_MADVISE
 #ifdef MADV_DONTFORK
--- a/src/osal.h
+++ b/src/osal.h
@@ -1,7 +1,7 @@
 /* https://en.wikipedia.org/wiki/Operating_system_abstraction_layer */

 /*
- * Copyright 2015-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2015-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -72,6 +72,10 @@ if(UNIX AND NOT SUBPROJECT)
  target_include_directories(test_extra_upsert_alldups PRIVATE "${PROJECT_SOURCE_DIR}")
  target_link_libraries(test_extra_upsert_alldups ${TOOL_MDBX_LIB})

+  add_executable(test_extra_dupfixed_addodd extra/dupfixed_addodd.c)
+  target_include_directories(test_extra_dupfixed_addodd PRIVATE "${PROJECT_SOURCE_DIR}")
+  target_link_libraries(test_extra_dupfixed_addodd ${TOOL_MDBX_LIB})
+
  if(MDBX_BUILD_CXX)
    add_executable(test_extra_maindb_ordinal extra/maindb_ordinal.c++)
    target_include_directories(test_extra_maindb_ordinal PRIVATE "${PROJECT_SOURCE_DIR}")
@@ -168,6 +172,7 @@ else()

  if(UNIX AND NOT SUBPROJECT)
    add_test(NAME extra_upsert_alldups COMMAND test_extra_upsert_alldups)
+    add_test(NAME extra_dupfixed_addodd COMMAND test_extra_dupfixed_addodd)
    if(MDBX_BUILD_CXX)
      add_test(NAME extra_maindb_ordinal COMMAND test_extra_maindb_ordinal)
      add_test(NAME extra_dupfixed_multiple COMMAND test_extra_dupfixed_multiple)
--- a/test/append.c++
+++ b/test/append.c++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/test/base.h++
+++ b/test/base.h++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/test/cases.c++
+++ b/test/cases.c++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/test/chrono.c++
+++ b/test/chrono.c++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/test/chrono.h++
+++ b/test/chrono.h++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/test/config.c++
+++ b/test/config.c++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
@@ -667,7 +667,10 @@ bool actor_config::deserialize(const char *str, actor_config &config) {
  }
  str = slash + 1;

-  uint64_t verify = std::stoull(std::string(str));
+  uint64_t verify = 0;
+  while (*str >= '0' && *str <= '9')
+    verify = verify * 10 + *str++ - '0';
+
  if (checksum.value != verify) {
    TRACE("<< actor_config::deserialize: checksum mismatch\n");
    return false;
--- a/test/config.h++
+++ b/test/config.h++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/test/dead.c++
+++ b/test/dead.c++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/test/extra/dupfixed_addodd.c
+++ b/test/extra/dupfixed_addodd.c
@@ -0,0 +1,93 @@
+/*
+ * @Dvirsw (https://t.me/Dvirsw)
+ * I think there is a bug with DUPFIXED. The following code fails.
+ *
+ * https://t.me/libmdbx/5368
+ */
+
+#include <sys/stat.h>
+#include <sys/time.h>
+
+#include "mdbx.h"
+#include <assert.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int main() {
+  int rc;
+  MDBX_env *env = NULL;
+  MDBX_dbi dbi = 0;
+  MDBX_val key, data;
+  MDBX_txn *txn = NULL;
+
+  rc = mdbx_env_create(&env);
+  if (rc != MDBX_SUCCESS) {
+    fprintf(stderr, "mdbx_env_create: (%d) %s\n", rc, mdbx_strerror(rc));
+    exit(EXIT_FAILURE);
+  }
+
+  rc = mdbx_env_set_maxdbs(env, 1);
+  if (rc != MDBX_SUCCESS) {
+    fprintf(stderr, "mdbx_env_create: (%d) %s\n", rc, mdbx_strerror(rc));
+    exit(EXIT_FAILURE);
+  }
+
+  rc = mdbx_env_open(env, "./example-db",
+                     MDBX_NOSUBDIR | MDBX_COALESCE | MDBX_LIFORECLAIM, 0664);
+  if (rc != MDBX_SUCCESS) {
+    fprintf(stderr, "mdbx_env_open: (%d) %s\n", rc, mdbx_strerror(rc));
+    exit(EXIT_FAILURE);
+  }
+
+  rc = mdbx_txn_begin(env, NULL, 0, &txn);
+  if (rc != MDBX_SUCCESS) {
+    fprintf(stderr, "mdbx_txn_begin: (%d) %s\n", rc, mdbx_strerror(rc));
+    exit(EXIT_FAILURE);
+  }
+
+  rc = mdbx_dbi_open(txn, "test", MDBX_DUPSORT | MDBX_DUPFIXED | MDBX_CREATE,
+                     &dbi);
+  if (rc != MDBX_SUCCESS) {
+    fprintf(stderr, "mdbx_dbi_open: (%d) %s\n", rc, mdbx_strerror(rc));
+    exit(EXIT_FAILURE);
+  }
+
+  char key_bytes[32] = {0};
+  key.iov_len = 32;
+  key.iov_base = key_bytes;
+
+  // Another put after this will fail.
+  unsigned char idx;
+  for (idx = 0; idx < 129; idx++) {
+    char data_bytes[15] = {idx};
+    data.iov_len = 15;
+    data.iov_base = data_bytes;
+    rc = mdbx_put(txn, dbi, &key, &data, 0);
+    if (rc != MDBX_SUCCESS) {
+      fprintf(stderr, "mdbx_put: (%d) %s\n", rc, mdbx_strerror(rc));
+      exit(EXIT_FAILURE);
+    }
+  }
+
+  // This will fail and exit.
+  char data_bytes[15] = {idx};
+  data.iov_len = 15;
+  data.iov_base = data_bytes;
+  rc = mdbx_put(txn, dbi, &key, &data, 0);
+  if (rc != MDBX_SUCCESS) {
+    fprintf(stderr, "mdbx_put: (%d) %s\n", rc, mdbx_strerror(rc));
+    fprintf(stderr, "expected failure\n");
+    exit(EXIT_FAILURE);
+  }
+
+  rc = mdbx_txn_commit(txn);
+  if (rc) {
+    fprintf(stderr, "mdbx_txn_commit: (%d) %s\n", rc, mdbx_strerror(rc));
+    exit(EXIT_FAILURE);
+  }
+}
--- a/test/extra/pcrf/pcrf_test.c
+++ b/test/extra/pcrf/pcrf_test.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2023 Leonid Yuriev <leo@yuriev.ru>.
+ * Copyright 2016-2024 Leonid Yuriev <leo@yuriev.ru>.
 * Copyright 2015 Vladimir Romanov
 * <https://www.linkedin.com/in/vladimirromanov>, Yota Lab.
 *
--- a/test/hill.c++
+++ b/test/hill.c++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/test/jitter.c++
+++ b/test/jitter.c++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
@@ -99,6 +99,37 @@ bool testcase_jitter::run() {
      jitter_delay();
      txn_begin(true);
      fetch_canary();
+      if (flipcoin()) {
+        MDBX_txn_info info;
+        err = mdbx_txn_reset(txn_guard.get());
+        if (err)
+          failure_perror("mdbx_txn_reset()", err);
+        err = mdbx_txn_info(txn_guard.get(), &info, false);
+        if (err != MDBX_BAD_TXN)
+          failure_perror("mdbx_txn_info(MDBX_BAD_TXN)", err);
+        err = mdbx_txn_reset(txn_guard.get());
+        if (err)
+          failure_perror("mdbx_txn_reset(again)", err);
+        err = mdbx_txn_break(txn_guard.get());
+        if (err)
+          failure_perror("mdbx_txn_break()", err);
+
+        err = mdbx_txn_abort(txn_guard.get());
+        if (err)
+          failure_perror("mdbx_txn_abort()", err);
+        txn_guard.release();
+        txn_begin(true);
+        err = mdbx_txn_reset(txn_guard.get());
+        if (err)
+          failure_perror("mdbx_txn_reset()", err);
+
+        err = mdbx_txn_renew(txn_guard.get());
+        if (err)
+          failure_perror("mdbx_txn_renew()", err);
+        err = mdbx_txn_info(txn_guard.get(), &info, false);
+        if (err)
+          failure_perror("mdbx_txn_info()", err);
+      }
      jitter_delay();
      txn_end(flipcoin());
    }
--- a/test/keygen.c++
+++ b/test/keygen.c++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/test/keygen.h++
+++ b/test/keygen.h++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/test/log.c++
+++ b/test/log.c++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/test/log.h++
+++ b/test/log.h++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/test/long_stochastic.sh
+++ b/test/long_stochastic.sh
@@ -432,6 +432,12 @@ for nops in 10 33 100 333 1000 3333 10000 33333 100000 333333 1000000 3333333 10
        --pagesize=$PAGESIZE --size-upper-upto=${db_size_mb}M --table=+data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%4]} \
        --keygen.seed=${seed}
+      caption="Probe #$((++count)) int-key,fixdups, split=${split}, case $((++subcase)) of ${cases}" probe \
+        --keygen.seed=${seed} --pagesize=$PAGESIZE --size-upper-upto=${db_size_mb}M --table=+key.integer,+data.fixed --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen=9 \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%4]}
+      caption="Probe #$((++count)) fixdups, split=${split}, case $((++subcase)) of ${cases}" probe \
+        --keygen.seed=${seed} --pagesize=$PAGESIZE --size-upper-upto=${db_size_mb}M --table=+data.fixed --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen=11 \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%4]}

      split=24
      caption="Probe #$((++count)) int-key,with-dups, split=${split}, case $((++subcase)) of ${cases}" probe \
@@ -446,6 +452,12 @@ for nops in 10 33 100 333 1000 3333 10000 33333 100000 333333 1000000 3333333 10
        --pagesize=$PAGESIZE --size-upper-upto=${db_size_mb}M --table=+data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%4]} \
        --keygen.seed=${seed}
+      caption="Probe #$((++count)) int-key,fixdups, split=${split}, case $((++subcase)) of ${cases}" probe \
+        --keygen.seed=${seed} --pagesize=$PAGESIZE --size-upper-upto=${db_size_mb}M --table=+key.integer,+data.fixed --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen=10 \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%4]}
+      caption="Probe #$((++count)) fixdups, split=${split}, case $((++subcase)) of ${cases}" probe \
+        --keygen.seed=${seed} --pagesize=$PAGESIZE --size-upper-upto=${db_size_mb}M --table=+data.fixed --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen=12 \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%4]}

      split=16
      caption="Probe #$((++count)) int-key,w/o-dups, split=${split}, case $((++subcase)) of ${cases}" probe \
@@ -468,6 +480,12 @@ for nops in 10 33 100 333 1000 3333 10000 33333 100000 333333 1000000 3333333 10
        --pagesize=$PAGESIZE --size-upper-upto=${db_size_mb}M --table=+data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%4]} \
        --keygen.seed=${seed}
+      caption="Probe #$((++count)) int-key,fixdups, split=${split}, case $((++subcase)) of ${cases}" probe \
+        --keygen.seed=${seed} --pagesize=$PAGESIZE --size-upper-upto=${db_size_mb}M --table=+key.integer,+data.fixed --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen=9 \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%4]}
+      caption="Probe #$((++count)) fixdups, split=${split}, case $((++subcase)) of ${cases}" probe \
+        --keygen.seed=${seed} --pagesize=$PAGESIZE --size-upper-upto=${db_size_mb}M --table=+data.fixed --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen=11 \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%4]}

      if [ "$EXTRA" != "no" ]; then
        split=10
@@ -491,6 +509,12 @@ for nops in 10 33 100 333 1000 3333 10000 33333 100000 333333 1000000 3333333 10
          --pagesize=$PAGESIZE --size-upper-upto=${db_size_mb}M --table=+data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=max \
          --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%4]} \
          --keygen.seed=${seed}
+        caption="Probe #$((++count)) int-key,fixdups, split=${split}, case $((++subcase)) of ${cases}" probe \
+          --keygen.seed=${seed} --pagesize=$PAGESIZE --size-upper-upto=${db_size_mb}M --table=+key.integer,+data.fixed --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen=13 \
+          --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%4]}
+        caption="Probe #$((++count)) fixdups, split=${split}, case $((++subcase)) of ${cases}" probe \
+          --keygen.seed=${seed} --pagesize=$PAGESIZE --size-upper-upto=${db_size_mb}M --table=+data.fixed --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen=16 \
+          --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%4]}
      fi

      split=4
@@ -506,6 +530,12 @@ for nops in 10 33 100 333 1000 3333 10000 33333 100000 333333 1000000 3333333 10
        --pagesize=$PAGESIZE --size-upper-upto=${db_size_mb}M --table=-data.dups --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen.min=min --datalen.max=1111 \
        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%4]} \
        --keygen.seed=${seed}
+      caption="Probe #$((++count)) int-key,fixdups, split=${split}, case $((++subcase)) of ${cases}" probe \
+        --keygen.seed=${seed} --pagesize=$PAGESIZE --size-upper-upto=${db_size_mb}M --table=+key.integer,+data.fixed --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen=21 \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%4]}
+      caption="Probe #$((++count)) fixdups, split=${split}, case $((++subcase)) of ${cases}" probe \
+        --keygen.seed=${seed} --pagesize=$PAGESIZE --size-upper-upto=${db_size_mb}M --table=+data.fixed --keygen.split=${split} --keylen.min=min --keylen.max=max --datalen=32 \
+        --nops=$nops --batch.write=$wbatch --mode=$(bits2options $bits)${syncmodes[count%4]}
    done # options
    loop=$((loop + 1))
    if [ -n "$LOOPS" ] && [ $loop -ge "$LOOPS" ]; then break; fi
--- a/test/main.c++
+++ b/test/main.c++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/test/nested.c++
+++ b/test/nested.c++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/test/osal-unix.c++
+++ b/test/osal-unix.c++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/test/osal-windows.c++
+++ b/test/osal-windows.c++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/test/osal.h++
+++ b/test/osal.h++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/test/test.c++
+++ b/test/test.c++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
@@ -24,9 +24,9 @@ const char *testcase2str(const actor_testcase testcase) {
  case ac_hill:
    return "hill";
  case ac_deadread:
-    return "deadread";
+    return "dead.reader";
  case ac_deadwrite:
-    return "deadwrite";
+    return "dead.writer";
  case ac_jitter:
    return "jitter";
  case ac_try:
@@ -733,6 +733,18 @@ void testcase::speculum_check_iterator(const char *where, const char *stage,
            mdbx_dump_val(&v, dump_value, sizeof(dump_value)));
 }

+void testcase::failure(const char *fmt, ...) const {
+  va_list ap;
+  va_start(ap, fmt);
+  fflush(nullptr);
+  logging::output_nocheckloglevel_ap(logging::failure, fmt, ap);
+  va_end(ap);
+  fflush(nullptr);
+  if (txn_guard)
+    mdbx_txn_commit(const_cast<testcase *>(this)->txn_guard.release());
+  exit(EXIT_FAILURE);
+}
+
 #if SPECULUM_CURSORS
 void testcase::speculum_check_cursor(const char *where, const char *stage,
                                     const testcase::SET::const_iterator &it,
--- a/test/test.h++
+++ b/test/test.h++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
@@ -277,6 +277,7 @@ protected:
  void signal();
  bool should_continue(bool check_timeout_only = false) const;

+  void failure(const char *fmt, ...) const;
  void generate_pair(const keygen::serial_t serial, keygen::buffer &out_key,
                     keygen::buffer &out_value, keygen::serial_t data_age) {
    keyvalue_maker.pair(serial, out_key, out_value, data_age, false);
--- a/test/ttl.c++
+++ b/test/ttl.c++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/test/utils.c++
+++ b/test/utils.c++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *
--- a/test/utils.h++
+++ b/test/utils.h++
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 Leonid Yuriev <leo@yuriev.ru>
+ * Copyright 2017-2024 Leonid Yuriev <leo@yuriev.ru>
 * and other libmdbx authors: please see AUTHORS file.
 * All rights reserved.
 *