log4cplus-2.2.1

[Bruce Dubbs]

New point version.

[Joe Locash]

# Unreleased (2.2.1)

  - **IMPORTANT**: CMake builds now require CMake 3.20 or later. The
    implementation language remains C++11. GitHub PR #698.

  - **IMPORTANT**: iOS builds now use CMake's native platform support. The
    legacy custom iOS toolchain, `IOS_PLATFORM`/`CMAKE_IOS_*` variables, and
    ARMv7/i386 build scripts have been removed. The obsolete Android
    `LIBRARY_OUTPUT_PATH_ROOT` toolchain integration has also been removed.
    GitHub PR #698.

  - Prevent `DailyRollingFileAppender` process-exit rollover from accessing a
    destroyed directory separator string when `RollOnClose` is enabled. Keep
    the separator valid throughout shutdown by using a constant character.
    GitHub issue #272. GitHub PR #711.

  - Fix `TimeBasedRollingFileAppender` archive cleanup when consecutive
    cleanups cross a partial rollover period, so expired archives are not
    skipped during sparse logging. GitHub issue #634. GitHub PR #687,
    backported in #690. (fhgffy)

  - Fix `TimeBasedRollingFileAppender` rollover when `File` is omitted or
    empty. Keep completed dated files and append to the next `FilenamePattern`
    destination, preserving existing messages during repeated rollover and
    `RollOnClose`. Initial opening still honors `Append`. GitHub issue #668.
    GitHub PR #697.

  - Honor `CreateDirs` for dated archive directories in
    `TimeBasedRollingFileAppender` with a fixed `File`. On rename failure,
    preserve the active log and retry the original archive destination on the
    next eligible event instead of truncating the log. Report rename errors
    through the appender's error handler. GitHub issue #644. GitHub PR #708.

  - Fix `TimeBasedRollingFileAppender` period recovery across sequential
    process restarts. Use the modification time of a nonempty fixed `File`
    opened with `Append=true` to select its archive period, and roll over an
    expired period before writing the first eligible new event. Retain that
    period through stream reopens and failed rollover retries. GitHub issue
    #588. GitHub PR #710.

  - Fix accounting for asynchronous events dropped when the nonblocking thread
    pool queue is full. Appender shutdown and destruction can now finish after
    accepted events drain when `log4cplus.threadPoolBlockOnFull=false`. GitHub
    PR #694.

  - Fix asynchronous event accounting when an accepted nonblocking task
    finishes with an exception before its result is polled. Decrement the
    pending count only once, preventing unsigned underflow and shutdown hangs
    after queued work has drained. GitHub PR #716.

  - Fix `AsyncAppender::close()` to join its queue worker even after the
    worker stops running, so `close()` waits for thread-local cleanup after
    worker failure. Preserve queue draining and the synchronous logging
    fallback. GitHub PR #705.

  - Update the internal ThreadPool to recover safely from worker creation and
    pool growth failures, create one worker when a zero size is requested,
    reclaim retired workers, and wait for complete worker exit during
    shutdown. GitHub issue #646. GitHub PR #701 and ThreadPool PR
    log4cplus/ThreadPool#3.

  - Fix Windows DLL cleanup hangs and crashes during process termination
    through `exit()` or `ExitProcess()`. Skip resource cleanup once Windows
    has started terminating threads. Pending logging may be lost during
    process termination; orderly shutdown still drains accepted events. GitHub
    issue #408. GitHub PR #703.

  - Keep fractional timestamp padding for `%q` and `%Q` valid during startup
    and shutdown by replacing global strings with constant literal tables.
    Preserve the existing formatted output. GitHub issue #273. GitHub PR #714.

  - Fix installed CMake packages to discover `Threads` for static
    multithreaded libraries and provide `log4cplus::log4cplus` for static and
    Unicode builds with decorated library names. Add installed-package
    consumer regression coverage for shared/static and narrow/Unicode
    configurations. GitHub PR #690.

  - Generate CMake pkg-config metadata using the selected library name,
    including static/Unicode decoration and the Windows Debug postfix. Refresh
    the installed metadata when switching build configurations. GitHub PR
    #698.

  - Enable the internal thread pool in the handwritten MSBuild projects,
    restoring asynchronous logging support in both shared and static builds.
    GitHub PR #698.

  - Fix Windows archive-cleanup unit-test compilation and fixture creation.
    Remove an obsolete Win32 stream test source dependency from MinGW
    Autotools builds. GitHub PR #691 and #698.

  - Move Visual Studio 2019 and 2022 CMake/MSBuild CI builds to GitHub Actions
    with explicit `v142`/`v143` toolsets. Retain Visual Studio 2017 on
    AppVeyor and update its CMake installation to satisfy the new minimum
    version. GitHub PR #691 and #699.

  - Support native CMake device and Simulator builds for iOS 15 and later. iOS
    builds default to static libraries with tests and the logging server
    disabled, and disable interprocedural optimization so that installed
    archives can be packaged into an XCFramework. GitHub PR #698.

  - Add the Android-only `log4cplus::AndroidAppender`, which writes formatted
    events to Logcat through system `liblog`. Its `Tag` property defaults to
    `log4cplus`; tags and long message chunks preserve UTF-8 boundaries.
    Android production builds now link `liblog`, with static CMake consumers
    receiving the dependency without an absolute NDK path. GitHub PR #698.

  - Modernize Android build and installed-package validation using NDK r29,
    C++11, API level 21, and all four current NDK ABIs. The logging server now
    defaults to disabled on Android. GitHub PR #698.

  - Add iOS archive and XCFramework CI validation. Mobile CI checks
    compilation, linking, installation and packaging, without running device
    tests. GitHub PR #698.

  - Preserve the configured IPv6 setting when `SocketAppender` and
    `SysLogAppender` reconnect. Improve Apple socket portability by preventing
    `SIGPIPE` on socket writes and avoiding descriptor and size narrowing.
    GitHub PR #698.

Fixed at e8f228ae56.