Adding upstream version 2.11.2.upstream/2.11.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1770 insertions, 0 deletions

diff --git a/NEWS.md b/NEWS.md
new file mode 100644
index 0000000..4547a5d
--- /dev/null
+++ b/NEWS.md
@@ -0,0 +1,1770 @@
+man-db 2.11.2 (8 January 2023)
+==============================
+
+Fixes:
+
+ * Fix compile and test failures when `troff` is not `groff`.
+ * Fix segfault in typical uses of `man` when `nroff` is not installed.
+ * Fix crash in `mandb` when processing stray cats.
+
+Improvements:
+
+ * Check for stray cats even if no manual pages in a given manpath were
+   changed.
+
+man-db 2.11.1 (15 November 2022)
+================================
+
+Build:
+
+ * Transfer Git repository to https://gitlab.com/man-db/man-db.
+
+Fixes:
+
+ * SECURITY: Replace `$` characters in page names with `?` when constructing
+   `less` prompts.
+ * Silence error message when processing an empty manual page hierarchy with
+   a nonexistent cache directory.
+ * `man(1)` now sorts whatis references below real pages, even if the whatis
+   references are from a section with higher priority.
+
+Improvements:
+
+ * Add section `3type` to the default section list just after `2`.  This is
+   used by the Linux man-pages package.
+ * Recognize more Hungarian translations of the `NAME` section.
+
+man-db 2.11.0 (15 October 2022)
+===============================
+
+Fixes:
+
+ * `mandb` now correctly records filters in the database if it uses cached
+   whatis information.
+ * Upgrade Gnulib, fixing syntax error on glibc systems with GCC 11.
+ * The `CATWIDTH` configuration file directive now overrides `MINCATWIDTH`
+   and `MAXCATWIDTH`.
+ * Database entries for links were often incorrectly stored as if they were
+   entries for the ultimate source of the page.  They are now stored with
+   the correct type.
+ * Store links in the database using the section and extension of the link
+   rather than of the ultimate source file.
+ * Consider pages for adding to the database even if they seem to already
+   exist; this performance optimization is no longer needed due to caching,
+   and it produced inconsistent results in some unusual cases.
+ * `man` now runs any required preprocessors in the same order that `groff`
+   does, rather than trusting the order of filters in a page's preprocessor
+   string.
+ * Fix building on MinGW.  (I haven't been able to test this; help from
+   MinGW experts would be welcome.)
+
+Improvements:
+
+ * Add more recognized case variants for localized versions of the `NAME`
+   section.
+ * Maintain multi keys in sorted order, improving database reproducibility.
+ * Pick a more consistent name for the target of a whatis entry in the
+   database.
+ * Extend rules for when to replace one database entry with another,
+   producing more stable behaviour.
+ * Fully reorganize databases after writing them, allowing the reproduction
+   of bitwise-identical databases regardless of scan order (at least with
+   GDBM).
+
+man-db 2.10.2 (17 March 2022)
+=============================
+
+Build:
+
+ * Regenerating man-db's build system now explicitly requires Automake >=
+   1.14.  (This was already the case since at least man-db 2.10.0, but was
+   previously undocumented.)
+
+Fixes:
+
+ * Make `man -H` sleep for a few seconds after starting the browser, since
+   it may background itself before loading files (Dr. Werner Fink).
+ * If an override directory is configured using `--with-override-dir`, it is
+   now applied more consistently when building the manpath, and whether a
+   page was found in an override directory is considered when sorting
+   candidates for display (Mihail Konev).
+
+Improvements:
+
+ * Make the man-db manual build reproducible.
+ * Add some hardening options to the `systemd` service.
+ * `configure` now has a `--with-snapdir` option, for use on systems where
+   `snapd` is configured to use a directory other than `/snap`.
+
+man-db 2.10.1 (10 February 2022)
+================================
+
+Fixes:
+
+ * Fix occasional `mandb-symlink-target-timestamp` test failure.
+ * Fix inadvertent reliance on a GCC extension that caused build failures
+   with Clang.
+ * Fix building without `iconv`.
+ * Fix building on Cygwin.
+
+man-db 2.10.0 (4 February 2022)
+===============================
+
+Build:
+
+ * Move Git repository to GitLab (https://gitlab.com/cjwatson/man-db).
+ * Building man-db now requires a C99 compiler.
+ * Building man-db now requires Autoconf >= 2.64.
+
+Fixes:
+
+ * Manpath deduplication no longer mishandles the case where another entry
+   in the manpath is a suffix of a candidate path to append.
+ * Fix potential crash in path searching if `getcwd` fails for reasons other
+   than running out of memory.
+ * Fix crash in `globbing` test tool if run with no non-option arguments.
+ * `lexgrog` now produces output in the user's locale.
+ * Downgrade "malformed .lf request" warning to a debug message and rephrase
+   it somewhat, since `.lf` requests can use `*roff` arithmetic expressions
+   and we can't reasonably parse those.
+ * Avoid modifying the database without changing its mtime, which had been
+   possible since 2.7.0 if `mandb`'s purge phase found work to do but the
+   main phase didn't, and which confused some backup systems into reporting
+   possible filesystem corruption.
+ * `man` no longer inadvertently modifies the `MANSECT` environment variable
+   before passing it on to its subprocesses.
+ * `mandb` now stores the mtime of link targets as the mtime of their
+   corresponding database entries, rather than sometimes storing the mtime
+   of the link instead.
+ * Since man-db 2.4.2, `man` has behaved as if the `-l` option was given if
+   a manual page argument contains a slash.  Since man-db 2.5.6, this has
+   interacted slightly poorly with the subpage feature, emitting spurious
+   error messages if given multiple manual page arguments some of which
+   include a slash.  `man` no longer emits spurious error messages in this
+   case.
+
+Improvements:
+
+ * Reduce overhead of `MAN_DISABLE_SECCOMP=1` compared to building without
+   `libseccomp`.
+ * Document `MAN_DISABLE_SECCOMP` and `PIPELINE_DEBUG` environment variables
+   in `man(1)`.
+ * Add `man-pages(7)` reference to `man(1)`.
+ * Recognize Arabic and Persian translations of the `NAME` section.
+ * Delay the `systemd` timer using `RandomizedDelaySec`, so that multiple
+   containers/VMs on the same host are less prone to running `mandb` all at
+   the same time.
+ * Significantly improve `mandb(8)` and `man -K` performance in the common
+   case where pages are of moderate size and compressed using `zlib`: `mandb
+   -c` goes from 344 seconds to 10 seconds on a test system.
+
+man-db 2.9.4 (8 February 2021)
+==============================
+
+Improvements:
+
+ * Recognise Romanian translations of the NAME section.
+ * Treat `\[en]` (etc.) as another synonym for `\-` in NAME sections,
+   alongside the existing `\(en` (etc.).
+
+Fixes:
+
+ * Make the `seccomp` sandbox work better with libcs such as `musl` (S.
+   Gilles).
+ * Make the `seccomp` sandbox allow `clock_gettime64` as well as
+   `clock_gettime` (S. Gilles).
+
+man-db 2.9.3 (22 June 2020)
+===========================
+
+Fixes:
+
+ * Fix manual page translation infrastructure to compare `po4a` versions
+   with more than two components correctly.
+ * Avoid incorrect markup in `man(1)` with `po4a >= 0.58`.
+
+man-db 2.9.2 (1 June 2020)
+==========================
+
+Fixes:
+
+ * Fix `man -X75-12` and `man -X100-12` to set the document font size (using
+   `-rS12`) as well as the device (using `-TX75-12` or `-TX100-12`).
+ * Fix incompatibility of `man -X` and friends with the `seccomp` sandbox.
+
+Improvements:
+
+ * Add a bug tracker link to man-db's own manual pages.
+ * Add support for `zstd`-compressed manual pages, thanks to Bernhard
+   Rosenkränzer.
+
+man-db 2.9.1 (25 February 2020)
+===============================
+
+Improvements:
+
+ * Drop `fdutimens` patch for GNU/Hurd; the bug it was working around was
+   fixed in glibc 2.28.
+ * Add `MANDB_MAP` entry mapping `/snap/man` to `/var/cache/man/snap`.
+
+man-db 2.9.0 (23 October 2019)
+==============================
+
+Fixes:
+
+ * `man --recode` and `manconv` now adjust encoding declarations on the
+   first line of their input to refer to the new encoding.
+ * Fix comparison of candidate manual pages to correctly handle the case
+   where the language elements are the same and match the locale, but the
+   territory elements differ.
+
+Improvements:
+
+ * Many typographical improvements to man-db's own manual pages, largely
+   thanks to Bjarni Ingi Gislason.
+ * Rewrite parts of `man(1)` to make it a more accessible introduction.
+ * If run with no arguments or only a section, `man` now suggests running
+   `man man`.
+ * `man` now understands the `<page>(<section>)` form on its command line,
+   so for example `man 'chmod(2)'` is now the same as `man 2 chmod`.  While
+   this requires more quoting, it may also be more convenient when copying
+   and pasting cross-references to manual pages.
+ * `manconv` now guesses the input encoding based on the file name if it is
+   not explicitly specified.
+ * There is a new `man-recode` program.  It fulfils a purpose similar to
+   `man --recode`, but has an interface designed for bulk conversion and so
+   can be much faster when used on a large number of pages.
+
+Compatibility notes:
+
+ * Remove the ability to undefine `COMP_SRC` at build-time to disable
+   reading compressed manual pages.  This was always only a
+   micro-optimisation, and it wasn't worth the extra code complexity.  You
+   can still configure without any compressors (either by not having them
+   available at build time, or by configuring with `--with-gzip=` etc.) to
+   achieve much the same practical effect, although the test suite still
+   requires at least `gunzip`.
+
+man-db 2.8.7 (26 August 2019)
+=============================
+
+Fixes:
+
+ * Further workarounds for ESET File Security: allow `sendmsg` when it is in
+   use.
+ * The `seccomp` sandbox now causes disallowed system calls to return
+   `EPERM` rather than raising `SIGSYS`, in the hope of being less
+   disruptive to preload hacks.
+ * Make `seccomp` sandbox allow `getrandom`, used by Hardened Malloc.
+ * `man` no longer saves cat pages if `--no-hyphenation` or
+   `--no-justification` is used.
+ * Move decompression code out of `libman`.  This should really fix a link
+   failure using the Darwin linker (unsuccessfully attempted in 2.8.6), and
+   possibly on other platforms too.
+ * Pass the database file name around in function parameters, rather than
+   storing it in a global variable with an unresolved symbol from
+   `libmandb`.  Like the previous item, this fixes a link failure using the
+   Darwin linker, and possibly on other platforms too.
+ * Return database entries in sorted order when using NDBM.  (This is based
+   on a similar fix to the GDBM backend in man-db 2.4.2.)
+
+Improvements:
+
+ * Recognise Esperanto, Tamil, and Ukrainian translations of the `NAME`
+   section.
+
+man-db 2.8.6.1 (5 August 2019)
+==============================
+
+Fixes:
+
+ * Fix missing memory copies in `ult_src` that caused segfaults in `mandb`.
+
+man-db 2.8.6 (3 August 2019)
+============================
+
+Fixes:
+
+ * If more than one of `../man`, `man`, `../share/man`, and `share/man`
+   exist relative to a directory on `$PATH`, then all of them are now added
+   to the automatically-determined manpath; previously, only the first was
+   considered.
+ * Remove arbitrary limit on manpath size.
+ * The `systemd` database maintenance service now runs `mandb` with the
+   `--quiet` option, avoiding excess log messages.
+ * Default to `--without-systemdsystemunitdir` and
+   `--without-systemdtmpfilesdir` on non-Linux systems.
+ * Fix failure to link `libman` using the Darwin linker.
+ * `apropos -w` now works when given a non-lower-case pattern.
+
+Improvements:
+
+ * Convert most list and hash table code to Gnulib's container types: these
+   are more flexible and normally more concise than home-grown equivalents.
+ * There is a new configure option `--disable-manual`, which causes the
+   man-db manual not to be built or installed.
+
+man-db 2.8.5 (5 January 2019)
+=============================
+
+Build:
+
+ * Building man-db now requires Autoconf >= 2.63 and Automake >= 1.11.2.
+
+Fixes:
+
+ * Fix build with Berkeley DB.
+ * Fail to configure if `flex` is needed but missing.
+ * Fix the comment in the first line of the configuration file in the case
+   where `configure` was not given a `--with-config-file` option.
+ * Fix several resource and memory leaks.
+ * Fix handling of `\-` in the right-hand side of a `NAME` section.
+ * Work around Microsoft's proprietary "System Center Endpoint Protection"
+   antivirus program in the seccomp sandbox.
+
+Improvements:
+
+ * Ship a `systemd` timer to perform daily database maintenance.
+ * Allow disabling the installation of the `systemd` `tmpfiles` snippet and
+   the `systemd` timer by configuring with `--with-systemdtmpfilesdir=no`
+   and `--with-systemdsystemunitdir=no` respectively.
+
+man-db 2.8.4 (27 July 2018)
+===========================
+
+Fixes:
+
+ * Rely on decompressors reading from their standard input rather than
+   redundantly passing them the input file on their command line.  This
+   works better with downstream AppArmor confinement of decompressors.
+ * Fix invalid syntax in `tmpfiles.d/man-db.conf` when configured with
+   `--disable-cache-owner`.
+ * Make `seccomp` sandbox allow `sched_getaffinity`, sometimes used by `xz`.
+ * Check for `mandb_nfmt` and `mandb_tfmt` in the manual page hierarchy as
+   documented, not in the current directory.  This was broken by the
+   working-directory-handling changes in 2.8.3.  Note that this change means
+   that `man -l` will never use an external formatter (which was never
+   documented behaviour and was surely a bad idea).
+ * Make `seccomp` sandbox allow some shared memory operations across the
+   board rather than just when ESET File Security is in use; the Astrill VPN
+   seems to require something similar, and there are doubtless other such
+   preload hacks.
+ * Some versions of ESET File Security call `msgget` and `msgsnd`; if this
+   program is in use, then allow those.
+
+man-db 2.8.3 (5 April 2018)
+===========================
+
+Fixes:
+
+ * Make `seccomp` sandbox allow `madvise`, since that's used by `lbzip2`.
+ * Make `seccomp` sandbox allow `kill` and `tgkill` outright, since `groff`
+   uses `kill` to pass on signals to its child processes.
+ * Make `seccomp` sandbox allow sibling architectures on
+   `x86`/`x86_64`/`x32`, since people sometimes mix and match architectures
+   there for performance reasons.
+ * Fix version check in locale macro loading to tolerate `groff` release
+   candidates.
+ * `man` now only changes working directory in child processes, so never
+   fails due to being unable to change back to its original working
+   directory.
+ * `accessdb`, `apropos`, and `lexgrog` no longer emit spurious `gettext`
+   headers in their `--help` output when localised.
+
+man-db 2.8.2 (28 February 2018)
+===============================
+
+Fixes:
+
+ * Make `seccomp` sandbox allow `kill` and `tgkill` when the signal is
+   directed at the current process or one of its threads; this is needed by
+   `xz`.
+ * Make `seccomp` sandbox allow `ioctl(fd, TIOCGWINSZ)`, since that's used
+   by `musl`.
+ * Work around the proprietary "ESET File Security" antivirus program in
+   `seccomp` sandbox: if this is in use then we need to allow some
+   socket-related system calls.
+ * Work around the `snoopy` `execve()` wrapper and logger in `seccomp`
+   sandbox: if this is in use then we need to allow some socket-related
+   system calls.
+ * Interpret `EFAULT` from `seccomp_load` as meaning that `seccomp` is
+   unavailable, since this can be returned by some versions of `qemu-user`.
+
+man-db 2.8.1 (9 February 2018)
+==============================
+
+Fixes:
+
+ * Fix `seccomp` sandbox build on Linux/POWER.
+ * Fix `manconv` execution under `seccomp` when `man` is installed setuid.
+ * Make `seccomp` sandbox allow `mremap` (used by `iconv`, for example).
+
+Improvements:
+
+ * `configure` now has a `--without-libseccomp` option to disable the use of
+   `seccomp` even if the library is available.
+
+man-db 2.8.0 (4 February 2018)
+==============================
+
+Fixes:
+
+ * Fix locale macro loading for Chinese to load the macro file corresponding
+   to just the language part of the user's locale.
+ * Honour `--enable-cache-owner` in generated `systemd` `tmpfiles` snippet
+   rather than hardcoding `man`.
+ * If `man` adds prefixes to a page to handle such things as disabling
+   hyphenation, then take account of those when looking for a preprocessor
+   line at the start of the page.
+ * Fix a segfault in `man -D --help`.
+
+Improvements:
+
+ * Treat `\(en` as another synonym for `\-` in NAME sections.
+ * Confine most subprocesses that handle untrusted data using `seccomp`.
+   This mainly deals with subprocesses that perform encoding conversions,
+   (de)compressors, `groff` programs, and a few other odds and ends.
+   `groff` programs use a slightly more permissive filter since they need to
+   create temporary files, so additional path-based confinement (e.g. using
+   AppArmor) is still useful.
+
+   If this goes wrong, then `MAN_DISABLE_SECCOMP=1` can be set in the
+   environment to disable it, but please report any such problem as a bug.
+
+ * `man` now falls back to `cat` if the compile-time default pager is not
+   executable.
+
+man-db 2.7.6.1 (12 December 2016)
+=================================
+
+Fixes:
+
+ * Don't `chmod` `CACHEDIR.TAG` if it doesn't exist.
+ * Correct installation of Swedish manual pages.
+
+man-db 2.7.6 (11 December 2016)
+===============================
+
+Fixes:
+
+ * Fix build warnings with Perl 5.22.
+ * Document that `man -K` searches page source, not rendered text.
+ * Fix a long-standing bug in man-db's internal cleanup stack mechanism: if
+   a cleanup function was pushed unexpectedly between a push/pop pair, then
+   popping the stack would remove the wrong cleanup function and chaos could
+   ensue.  Avoid this by being more precise about which cleanup function
+   should be popped.
+ * SECURITY: Eliminate dangerous setgid-root directories.  In the default
+   configuration, cache files and directories are now owned by `man:man`
+   rather than `man:root`; `man` and `mandb` are now setgid `man` as well as
+   setuid `man` (except in the `--disable-setuid` case).  This is a much
+   simpler and safer solution to the original problem that caused my
+   predecessor to make directories setgid `root`, and doesn't introduce any
+   interesting new privilege since the `man` group's only real purpose is to
+   be the `man` user's primary group and nothing in cache directories is
+   group-writeable.
+
+   Maintainers of distribution packages should take care to review their
+   installation rules in light of this change.
+
+   As far as I know this has no CVE ID, but it is described
+   [here](https://www.halfdog.net/Security/2015/SetgidDirectoryPrivilegeEscalation/).
+
+ * Fix manual page translation infrastructure to render tables correctly
+   with `po4a` 0.47.
+
+Improvements:
+
+ * `man` now understands the `<page>.<section>` form on its command line, so
+   for example `man chmod.2` is now the same as `man 2 chmod`.  (Contributed
+   by Mihail Konev.)
+ * The owner of cache files is now configured separately from whether `man`
+   and `mandb` are installed setuid, using the `--enable-cache-owner[=USER]`
+   option.
+
+man-db 2.7.5 (6 November 2015)
+==============================
+
+Fixes:
+
+ * Adjust line number when inserting extra roff input.
+ * Disable roff input insertion with `--recode`.
+ * Build text manual with `LC_ALL=C`, to help reproducible builds.
+
+man-db 2.7.4 (8 October 2015)
+=============================
+
+Fixes:
+
+ * Fix crash when eliminating manpath duplicates if canonicalising a manpath
+   entry fails.
+ * Fix a build system bug that sometimes caused substitutions in manual
+   pages to be left unexpanded.
+ * `man` exits with status 3 rather than 0 if its formatting command exits
+   non-zero, even if its display command exits zero.
+ * `man` honours `MANWIDTH` in conjunction with the `-Z` option, to make it
+   easier to diagnose warnings in manual pages.
+
+man-db 2.7.3 (9 September 2015)
+===============================
+
+Fixes:
+
+ * Tools that consider the terminal line length now try the `TIOCGWINSZ`
+   ioctl on `/dev/tty` as well as standard input/output.
+ * `mandb` does a better job of coping with index files having incorrect
+   ownership.
+ * Squeeze blank lines internally rather than relying on the pager
+   supporting the `-s` option.
+ * Fix use-after-free in `ult_src`.
+ * Fix crash when running from a missing and unreadable current directory,
+   such as an orphaned subdirectory of `/proc`.
+ * Restore the ability to use `man -a` noninteractively.
+
+man-db 2.7.2 (16 August 2015)
+=============================
+
+Fixes:
+
+ * `man -k` and `man -f` now pass any provided `-l` option through to the
+   underlying `apropos`/`whatis` programs.
+ * `apropos` and `whatis` no longer truncate names if long output was
+   requested.
+ * The database handle is no longer stored in a global variable, fixing a
+   class of possible double-close bugs.
+
+man-db 2.7.1 (7 November 2014)
+==============================
+
+Fixes:
+
+ * Various portability fixes for Solaris, contributed by Peter Bray.
+ * `man` now runs correctly when its current working directory has been
+   deleted.  (As a result of this fix, man-db now requires `libpipeline >=
+   1.4.0`.)
+ * `man -a` sends its prompts to `/dev/tty` rather than to `stderr`, and
+   likewise reads replies from `/dev/tty` rather than from `stdin`.
+
+man-db 2.7.0.2 (28 September 2014)
+==================================
+
+Fixes:
+
+ * Be more careful to avoid using or double-closing closed database handles.
+   Fixes test suite failures on some systems.
+ * Patch the `fdutimens` function imported from Gnulib to work around a
+   libc bug in GNU/Hurd.
+
+man-db 2.7.0.1 (24 September 2014)
+==================================
+
+Fixes:
+
+ * Fix test suite in the case where the system supports high-precision
+   timestamps but the file system containing the build directory does not.
+
+man-db 2.7.0 (22 September 2014)
+================================
+
+Upgrading from previous versions:
+
+ * For the first time since version 2.4.0, the database format has changed
+   slightly, so you will need to run `mandb --create` after installing the
+   new version to rebuild your databases from scratch.  (Distribution
+   packages should do this automatically for system databases.)
+
+Fixes:
+
+ * `lexgrog` now filters terminal escape sequences out of cat pages before
+   trying to parse them.
+ * Tools that consider the terminal line length now prioritise the `COLUMNS`
+   environment variable above the `TIOCGWINSZ` ioctl.
+ * Manpath elements are no longer canonicalised before being inserted into
+   the search path; this caused the use of incorrect catpaths in some cases.
+   This was broken by the `LANGUAGE`-handling fixes in 2.5.4.
+
+Improvements:
+
+ * Ship a `systemd` `tmpfiles` snippet to clean up old cat files after a
+   week.
+ * The modification time of manual databases is now simply stored in the
+   mtime of the database files themselves, rather than using a special row.
+   This makes databases reproducible between otherwise-identical
+   installations, as long as the underlying database has predictable
+   behaviour.  As a bonus, man-db now uses high-precision timestamps to
+   determine whether it needs to update databases.
+ * Timestamps of manual pages are also now stored in the database with high
+   precision and compared accordingly.
+ * Files are now ordered by first physical extent before reading them, for
+   substantial performance improvements in operations such as `mandb` and
+   `man -K`.
+ * `man -H` shows a better error message if no browser is configured.
+ * `zsoelim` is now installed in `$pkglibexecdir`, to avoid clashes with
+   other packages.
+
+man-db 2.6.7.1 (10 April 2014)
+==============================
+
+Fixes:
+
+ * Remove test suite dependency on `realpath(1)`.
+
+man-db 2.6.7 (10 April 2014)
+============================
+
+Fixes:
+
+ * Fix a test failure when configured with `--enable-undoc`.
+ * Run the pager in `man`'s original working directory rather than in the
+   manual hierarchy.  (As a result of this fix, man-db now requires
+   libpipeline >= 1.3.0.)
+ * `mandb` only creates a cache directory tag if the catpath is different
+   from the manpath, since it should only be created in directories that
+   consist entirely of cached information.
+
+man-db 2.6.6 (23 January 2014)
+==============================
+
+man-db is now revision-controlled using git (https://git-scm.com/).  See
+`docs/HACKING` for the location of the repository.
+
+Fixes:
+
+ * `apropos`'s `--and` option now works again; it was broken by the
+   optimisations in 2.6.2.
+ * Restore compatibility with Automake 1.10.
+ * Improve support for translation of common elements of help messages.
+ * Don't issue error messages when the database refers to a page that no
+   longer exists.
+ * Pass macro and hyphenation language tags to `groff` again (broken in
+   2.6.5).
+
+Improvements:
+
+ * `./configure --with-override-dir=OVERRIDE` arranges to look for manual
+   pages in `DIR/OVERRIDE` before each path element `DIR`.
+
+man-db 2.6.5 (27 June 2013)
+===========================
+
+Fixes:
+
+ * `man`'s `--warnings` option works again on systems with versions of
+   `groff` that support it (broken in 2.6.4).
+ * `man` automatically falls back to `C.UTF-8` and then `en_US.UTF-8` if
+   trying to find a UTF-8 locale on a system without
+   `/usr/share/i18n/SUPPORTED`.
+
+man-db 2.6.4 (23 June 2013)
+===========================
+
+Fixes:
+
+ * `man(1)` and `catman(8)` now document the default section list set at
+   configure time.
+ * Build fixes for Automake 1.13.
+ * man-db 2.6.0 arranged to search the full manpath when expanding `.so`
+   directives in manual pages (so that `.so name.1` works as well as `.so
+   man1/name.1`), but this incorrectly did not take effect for manual pages
+   that consist only of a `.so` directive.  This is now fixed.
+
+Improvements:
+
+ * The `MANLESS` environment variable is now treated as if it were a default
+   value for the `-r` option to `man`: occurrences of the text `$MAN_PN` are
+   expanded, and explicitly using the `-r` option overrides the default.
+ * The (unfortunately still hardcoded) maximum length for paths to manual
+   page hierarchies in the configuration file is now 511 characters rather
+   than 49.
+ * `MANPATH` entries now undergo `glob(7)`-style wildcard expansion,
+   allowing entries such as `/opt/*/man`.
+
+man-db 2.6.3 (17 September 2012)
+================================
+
+Fixes:
+
+ * Build fixes for glibc 2.16 and Automake 1.12.
+
+man-db 2.6.2 (18 June 2012)
+===========================
+
+Fixes:
+
+ * `apropos` prints an error message and returns non-zero when it finds no
+   matches.  (Regression introduced in 2.5.1.)
+ * The presence of a 64-bit GDBM database on the manpath no longer causes a
+   32-bit `man` process to exit with a fatal error.
+
+Improvements:
+
+ * `apropos` is much faster when run with many arguments.
+ * `whatis` may be given the full path to an executable as an argument, in
+   which case it will look up the base name of that executable in the
+   appropriate parts of the manpath.
+
+man-db 2.6.1 (14 February 2012)
+===============================
+
+Fixes:
+
+ * `--with-db=db*` and `--with-db=ndbm` compile again.
+ * Translated manual pages are no longer displayed starting with a spurious
+   blank line.
+ * `straycats` tries to ensure that `col` is invoked with `LC_CTYPE` set to
+   a UTF-8 locale.
+ * Fix double-free in `mandb` when encountering a symlink outside the manual
+   hierarchy, thanks to Peter Schiffer.
+
+Improvements:
+
+ * `mandb` creates a cache directory tag, per the [Cache Directory Tagging
+   Standard](http://www.brynosaurus.com/cachedir/).
+ * Add support for Lzip-compressed manual pages, thanks to Matias A. Fonzo.
+ * Running `man -w` (with a new `--path` alias) without a name now prints
+   the manpath, for compatibility with other `man` implementations.  The
+   `vim` viewdoc plugin makes use of this.
+
+man-db 2.6.0.2 (13 April 2011)
+==============================
+
+Fixes:
+
+ * Fix a segfault when scanning links to empty pages.
+ * Once we've seen at least one record in a page's `NAME` section, ignore
+   any further records that don't include a `whatis` description, as they
+   tend to be noise.
+
+man-db 2.6.0.1 (10 April 2011)
+==============================
+
+Fixes:
+
+ * Ensure that the target of a symlink or `.so` chain is always recorded as
+   a real page.
+ * Read a user-specified configuration file even if `HOME` is unset.
+
+man-db 2.6.0 (9 April 2011)
+===========================
+
+Fixes:
+
+ * Fix build with versions of GNU `ld` that default to
+   `--no-copy-dt-needed-entries`.
+ * Fix failure to display manual pages in some encodings when installed
+   setuid.
+ * Wrap long table cells in `man(1)`, fixing test failures with `groff`
+   1.21.
+ * If an explicit section is passed to `man`, then pages that match that
+   section exactly will be preferred over pages that only have that section
+   as a prefix.
+ * Fix a segfault when `man -K` tries to display certain pages.
+ * Fix a segfault in some situations when processes are killed by `SIGHUP`,
+   `SIGINT`, or `SIGTERM`.
+
+Improvements:
+
+ * As promised in the release notes for man-db 2.5.8, man-db no longer ships
+   its own copy of [libpipeline](https://nongnu.org/libpipeline/).  You must
+   build and install that library separately.
+ * Search the full manpath when expanding `.so` directives in manual pages.
+   As part of this, `.so name.1` should now work as well as `.so
+   man1/name.1`.
+ * `lexgrog` handles roff named glyphs and `perldoc` strings in `NAME`
+   sections.
+ * `man` no longer starts a pager if standard output is not a tty.
+ * The `-s` option to `whatis` and `apropos` now takes a colon- or
+   comma-separated list of sections, similar to `man -S`.
+ * `mandb` error output is neater when `stderr` is not a terminal.
+ * Add basic support for the implementation of `nroff`/`troff` in the
+   Heirloom Documentation Tools.  Title lengths are not properly set as yet,
+   and many features are untested.
+ * `mandb` removes `cat*` and NLS subdirectories of `cat` directories whose
+   corresponding `man` directories no longer exist.
+ * `mandb` forces `SIGPIPE` back to its default disposition on startup, to
+   avoid noisy output in case it was started in a context where `SIGPIPE`
+   was ignored.
+ * `SECTION` entries in a user configuration file now override those in the
+   system configuration file, rather than appending to them.
+ * The default `less` prompt now includes "(press h for help or q to quit)"
+   to help novices find their way around.
+ * man-db may now be built to use Berkeley DB version 5 (`--with-db=db5`).
+
+man-db 2.5.9 (17 November 2010)
+===============================
+
+Fixes:
+
+ * Fix test failures on some systems.  A change made in 2.5.8 was overly
+   sensitive to directory ordering.
+ * Configuring with `--disable-nls` works again.
+
+man-db 2.5.8 (15 November 2010)
+===============================
+
+Fixes:
+
+ * Fix assertion failure on `man -l` with an uncompressed page and any of
+   `--no-hyphenation`, `--no-justification`, or a non-English page.
+ * 2.5.7 introduced a regression when running `catman` in some locales, most
+   notably in the C locale: while converting the output to UTF-8, `iconv`
+   was run after the compressor rather than before it.  This release fixes
+   that.
+
+Improvements:
+
+ * Add support for XZ-compressed manual pages, thanks to Darren Salt.
+ * Try underscore-separated subpages as well as hyphen-separated ones,
+   thanks to Tanguy Ortolo.
+ * Build `libman` and `libmandb` as shared libraries, reducing installed
+   footprint by about 200K (at least on GNU/Linux).
+ * `libintl` is no longer shipped with man-db.  If your system does not
+   already have GNU `libintl` installed and you want man-db's messages to be
+   translated, then please install [GNU
+   libintl](https://www.gnu.org/software/gettext/) separately.
+ * Warnings about unrecognised locales are now suppressed if the
+   `DPKG_RUNNING_VERSION` environment variable is set (i.e. man-db is
+   running within a Debian package's maintainer script), since the system
+   locales are often out of sync with the C library in that context.  Thanks
+   to the Debian Perl maintainers for the idea.
+ * Allow building with an external
+   [libpipeline](https://nongnu.org/libpipeline/), which has been split out
+   from man-db.  This is a transitional measure: a future version of man-db
+   will stop shipping its own copy of `libpipeline`.
+ * `mandb` should no longer repeatedly rescan manual page hierarchies when a
+   `whatis` entry turns into a broken link.
+
+man-db 2.5.7 (16 February 2010)
+===============================
+
+Fixes:
+
+ * If a subprocess exits before `man` manages to read all the output from
+   it, it now drains the output file descriptor rather than immediately
+   discarding it.
+ * If `/usr/share/i18n/SUPPORTED` is available, `man` attempts to use it to
+   ensure that `LC_CTYPE` is set to an appropriate locale for the selected
+   character set when invoking `col`.  This fixes `LANG=C man -E UTF-8`, as
+   used by lintian.
+ * Don't run tests if cross-compiling.
+ * Fix possible `mandb` crash when `MAN_MUST_CREATE` is unset.
+
+Improvements:
+
+ * `man` can now tell `nroff` to disable justification if the
+   `--no-justification` option is used.
+ * If the full path to an executable is given as an argument, `man` will try
+   looking up the corresponding manual page in the appropriate part of the
+   manpath, rather than just trying to format the text of the executable as
+   a manual page.
+ * In the GNU manual hierarchy layout, search `man<sec><ext>` directories as
+   well as just `man<sec>` (e.g. `/usr/share/man/man3p` as well as
+   `/usr/share/man/man3`).
+ * By request, `man` now prefers getting a page from the best manual section
+   over getting a page in the correct language.
+ * All programs now support a `MAN_DEBUG` environment variable which can be
+   used in place of the `-d`/`--debug` option.  This is useful in some
+   situations where a program is being called deep in a process tree.
+ * man-db now builds with heirloom-doctools, thanks to Diego Pettenò of
+   Gentoo.
+ * Add support for emulating `pipe()` with `socketpair()`, which is faster
+   on some systems; thanks to Werner Fink of SUSE.
+ * Cat pages are now always saved in UTF-8, and converted to the proper
+   encoding at display time, which means that cat pages can now be saved
+   regardless of locale. Note that a consequence of this is that cat pages
+   now include formatting information (e.g.  overstriking) and need to be
+   run through `col(1)` before display.
+
+man-db 2.5.6 (26 August 2009)
+=============================
+
+Fixes:
+
+ * Exact-section database lookups were incorrectly returning all database
+   entries whose section names were prefixes of the requested section name.
+   In some cases this could confuse `mandb` into never believing that the
+   database was up to date.
+ * Fix handling of pages with comma-separated names ("foo, bar, baz") in
+   their `NAME` sections, broken by a change in 2.5.0 (!) to ignore manual
+   page names containing spaces.
+ * Fixed a buffer overflow in the pipeline library's line-reading functions.
+   I don't believe this to be exploitable: at worst we might believe that
+   there's some garbage at the end of manual pages (whose contents are
+   untrusted anyway) and this bug typically resulted in a failed assertion
+   the next time anything tried to read a line.
+ * Plugged two substantial memory leaks in the pipeline library.
+ * `whatis` and `apropos` only display any given manual page, or pointers to
+   it, once.
+ * `man` now sets `less(1)`'s environment up correctly for manual pages
+   encoded in CP1251.
+ * `manconv` no longer confuses situations such as "this UTF-8 character is
+   not representable in the target encoding" with "this text is not in
+   UTF-8".
+
+Improvements:
+
+ * The default configuration file now includes section 0, used on some
+   systems to document C library header files.
+ * `make check` now passes in the presence of a UTF-8-aware `col`, such as
+   that in util-linux-ng.
+ * The `man -K` option is now supported to search the full text of all
+   manual pages.  This was inspired by a similar option in the other `man`
+   package (currently at version 1.6f) currently maintained by Federico
+   Lucifredi and formerly by Andries Brouwer, but I took advantage of
+   man-db's pipeline library to implement it entirely in-process, without
+   having to start a separate `grep` process for every manual page.  In my
+   tests with fairly typical searches across variously all manual pages or
+   just one section, man-db's implementation ran between 3 and 10 times
+   faster.
+ * Database directories are now only created when there are corresponding
+   manual page directories, not just because they're mentioned in the
+   configuration file.
+ * By default, `man` will now try to interpret pairs of manual page names
+   given on the command line as equivalent to a single manual page name
+   containing a hyphen (e.g. `man foo bar` => `foo-bar(1)`).  This supports
+   the common pattern of programs that implement a number of subcommands,
+   allowing them to provide manual pages for each that can be accessed using
+   similar syntax as would be used to invoke the subcommands themselves.
+   Suggested by H. Peter Anvin, Federico Lucifredi, and others on the git
+   mailing list.
+ * The build process is now quieter by default.  Use `./configure
+   --disable-silent-rules` or `make V=0` if you don't like this or your
+   `make(1)` doesn't support the non-standard extension required.
+ * `make install` now installs the manual.
+ * `manconv` understands a wider range of Emacs-style coding tags.
+ * Recommendations to change `MAN_DB_CREATES`, `MAN_DB_UPDATES`, and
+   `MAN_CATS` `#define` options in `manconfig.h` have been replaced by new
+   `configure` options `--enable-automatic-create`,
+   `--disable-automatic-update`, and `--disable-cats` respectively.  Note
+   that automatic user database creation is now off by default, as it is
+   often too slow for the usefulness it adds; use
+   `--enable-automatic-create` to enable it.
+
+man-db 2.5.5 (14 March 2009)
+============================
+
+Fixes:
+
+ * Pages that declare a non-default encoding in their preprocessor lines are
+   now handled correctly.
+ * Fix an uninitialised variable when sorting manual page candidates that
+   could lead to excessive memory allocation and possible crashes.
+
+Improvements:
+
+ * man-db's `make check` now tests that all its own manual pages format
+   without errors or warnings from `groff`, to ensure a better-quality
+   release.
+
+man-db 2.5.4 (24 February 2009)
+===============================
+
+Fixes:
+
+ * Build fixes for systems without GNU Make, and for systems without
+   `gettext`; this successfully covers at least FreeBSD.
+ * The `distclean` target now works if `po4a` isn't installed.
+ * Exit as soon as possible if database writes return `ENOSPC`.
+ * `lexgrog` now stops on any unrecognised roff request, rather than
+   continuing and often littering the database with garbage.
+ * `man` no longer requires both standard input and standard output to be
+   terminals in order to use the terminal line length.  The line length from
+   standard output is preferred if available.
+ * The manpath was built completely wrongly when multiple entries were
+   present in `LANGUAGE`: duplicates were handled strangely, and languages
+   were effectively iterated in reverse order.  It should be rather more
+   sensible now.
+
+Improvements:
+
+ * The `MAN_KEEP_STDERR` environment variable can now be used to override
+   `man`'s default of discarding `stderr` when `stdout` is a terminal.
+ * Handling of terminal widths for cat pages is now configurable, using the
+   `MINCATWIDTH`, `MAXCATWIDTH`, and `CATWIDTH` configuration file
+   directives.
+ * `man -a` now detects duplicate manual page candidates more reliably, and
+   sorts them better.
+ * Belarusian, Estonian, Greek, Latvian, Lithuanian, Macedonian, Romanian,
+   Slovenian, and Ukrainian pages are now supported.
+ * `man` can now search for pages using regular expressions (with `--regex`)
+   or shell wildcards (with `--wildcard`).  By default this searches both
+   page names and descriptions, like `apropos`, but if the `--names-only`
+   option is used then it searches page names only, like `whatis`.
+ * `man` can now tell `nroff` to disable hyphenation if the
+   `--no-hyphenation` option is used.
+ * man-db already searched for manual pages in `../man` and `man`
+   directories relative to each `$PATH` component; it now searches in
+   `../share/man` and `share/man` directories too.
+ * Groff 1.20 was recently released, including the `preconv` preprocessor.
+   Although man-db has supported `preconv` to some extent since 2.4.4,
+   man-db's `configure` now detects its presence and infers that `groff`
+   supports Unicode input using it; `man` also now takes slightly better
+   advantage of `preconv` than before.
+ * Per-locale `groff` macros are now loaded if possible, allowing us to take
+   advantage of such things as localised versions of predefined strings and
+   language-aware hyphenation.  This only works with Groff 1.20.2 or better
+   (not yet released), since earlier versions did not allow us to suppress
+   warnings in the event that the appropriate macro file is not available.
+
+man-db 2.5.3 (17 November 2008)
+===============================
+
+Fixes:
+
+ * Cleaned up a number of possible crashes, memory leaks, and missing error
+   checks found by the Coverity Scan project.
+ * Fix build if `MAN_CATS` is undefined.
+ * If the `LINGUAS` environment variable is set while running `configure`,
+   it now controls building and installation of localised manual pages as
+   well as program translations.
+ * The `LANGUAGE` environment variable is now tokenised properly, rather
+   than only taking the first two characters of each element.
+ * Fix build if `--disable-nls` is used or `iconv` is not available.
+ * `man` now correctly propagates the exit code of `whatis` or `apropos`
+   when called with the `-f` or `-k` option respectively.
+
+Improvements:
+
+ * A number of inconsistencies and readability problems with man-db's own
+   manual pages have been cleaned up, thanks mainly to Yuri Kozlov.
+ * Reduce the number of warnings emitted when using an unrecognised locale.
+ * `manconv` and `zsoelim` are now called internally rather than by
+   executing external programs, to improve performance.
+ * man-db now uses GDBM (`--with-db=gdbm`) in preference to Berkeley DB
+   (`--with-db=db` or `--with-db=dbN` where `N` is 1, 2, 3, or 4) by
+   default, since hardware improvements have rendered Berkeley DB's speed
+   advantages negligible for our purposes and the relatively frequent
+   `SONAME` and on-disk format changes are not worth the hassle.
+   Distributors should note that if they follow this change then they will
+   need to arrange for databases to be rebuilt on upgrade to this version.
+ * Manual pages may now be compressed with LZMA (although this is probably
+   only worth it for very large pages).
+ * Duplicate manual page hierarchies due to symlinks (e.g. `/usr/man` ->
+   `/usr/share/man`) are detected and removed from the search order.
+ * A locale modifier (e.g. `@latin`) in a directory name must now match the
+   locale if the former is set, in addition to the language and territory.
+ * Bare `.so` includes (e.g. `.so foo.1` rather than `.so man1/foo.1`) now
+   work, although only within the same manual page hierarchy for now.
+
+man-db 2.5.2 (5 May 2008)
+=========================
+
+Fixes:
+
+ * `man -H` (without a browser argument) was completely broken in 2.5.1 and
+   is now fixed.
+ * `man` no longer breaks in Japanese locales when using `less` as a pager.
+
+Improvements:
+
+ * The `--encoding` option to `man` can now take a true character encoding
+   rather than a `*roff` device; the latter was an unreliable, inflexible,
+   and awkward way to select an output encoding.  The old semantics are
+   still supported for backward compatibility.
+ * Whatis parsing stops at `.ie` or `.if` conditionals.
+ * CJK locale specifications where the codeset component is equivalent to
+   but not stringwise-identical to UTF-8 (e.g.  `zh_CN.utf8`) are handled
+   better.
+ * `man(1)`'s `OPTIONS` section is ordered more comprehensibly.
+ * `apropos`, `lexgrog`, `man`, `mandb`, and `whatis` ignore encoding
+   conversion errors for the last possible encoding of the source page.
+   This helps, for example, with pages including misencoded non-ASCII names
+   of authors; it usually seems better to allow these pages to pass with
+   small errors than to break them entirely.
+
+man-db 2.5.1 (28 January 2008)
+==============================
+
+Fixes:
+
+ * The manual is now built automatically, avoiding some ordering problems on
+   `make distclean`.
+ * Manual pages are converted to the proper input encoding for `troff`
+   output as well as `nroff` output.
+ * The `-t`, `-T`, `-X`, and `-Z` options to `man` work again; in 2.5.0,
+   they read input from `stdin` rather than from the manual page.
+ * `apropos` and `whatis` no longer segfault when given an explicit locale
+   using `-L`.
+ * `man` now understands that `groff`'s `ascii` device takes ASCII input,
+   not ISO-8859-1.
+ * `man` no longer discards `stderr` when writing to a file or a pipe; this
+   was broken by an overenthusiastic change in 2.5.0.
+ * `manconv` now falls back to the next encoding in its list if any
+   characters in an entire 64KB block fail to decode using the current
+   encoding, as was originally intended.
+ * `manconv` is more careful about extracting `coding:` directives from
+   manual pages.
+ * Ctrl-C and Ctrl-\ now work again at the prompt issued by `man -a`.
+
+Improvements:
+
+ * There is a new `--with-sections` `configure` option to change the default
+   value of `SECTION` in the configuration file.
+ * Automake is now used to generate Makefiles.  Among other things, this
+   fixes `VPATH` builds and some bugs in dependency generation, and should
+   allow building with non-GNU versions of make.
+ * man-db now uses the Gnulib portability library, allowing the removal of
+   earlier haphazard portability code.  While this results in a somewhat
+   larger source distribution, it makes man-db easier to maintain and should
+   make it easier to build on systems to which the maintainer does not have
+   access.
+ * In the process of switching to Gnulib, the last vestiges of pre-C89
+   support have been removed; they were documented to be broken anyway.
+ * If the `MANROFFOPT` environment variable is set, `man` now appends its
+   value to the `*roff` command line.
+ * `man` now accepts a `--recode` option to output a source manual page
+   converted to a specified encoding.
+ * For compatibility with System V, `man` accepts `-s` as an alias for `-S`,
+   and permits sections to be comma-separated as well as colon-separated.
+ * All programs, except the obsolete `wrapper`, now accept a `--debug`
+   option.  (`accessdb`, `lexgrog`, and `zsoelim` were lacking it.)
+ * `man` now accepts a `--warnings` option to enable `groff` warnings.
+
+man-db 2.5.0 (7 October 2007)
+=============================
+
+Fixes:
+
+ * `mandb --quiet` now suppresses several more warnings.
+ * The output of `apropos` no longer includes duplicates when multiple
+   search terms are used.
+
+Improvements:
+
+ * Databases are now created for non-English manual hierarchies.  All
+   database entries should be encoded in UTF-8; man-db converts from the
+   character set of the manual hierarchy and to the character set specified
+   in the user's locale as necessary.
+ * Per-locale directory handling has been improved.  Directories such as
+   `fr.UTF-8` may be used for occasions when it is appropriate to specify
+   the character set but not the country, and so a full locale name is
+   inconvenient.
+ * There is a new `manconv` program which can try multiple possible
+   encodings for a file, thus allowing UTF-8 manual pages to be installed in
+   any directory even without an explicit encoding declaration.
+ * A decompression library is now in place.  This allows man-db to use
+   `zlib` to decompress gzipped files, and allows most of its uses of
+   temporary files to be removed.  The only remaining exceptions are cat
+   file creation (which uses a temporary file in the cat tree rather than in
+   `/tmp`) and viewing HTML manual pages (which uses a temporary directory).
+   Otherwise, man-db should now work fine even with a read-only `/tmp`
+   during system recovery.
+ * Cat pages are now saved in the background while the pager is active, so
+   `man` will only need to block afterwards if the pager is exited very
+   quickly.
+ * `--with-*` options are now available at `configure` time for most of the
+   auxiliary program locations that you might want to override.
+ * `man` now supports the `MANPAGER` environment variable, overriding
+   `PAGER`.
+ * `apropos`/`whatis` output is now truncated to the terminal width by
+   default.  As with `man`, this may be overridden using the `MANWIDTH`
+   environment variable.
+ * `lexgrog` now ignores alleged manual page names containing spaces, as
+   these usually indicate parsing errors or ill-formed `NAME` sections and
+   they clutter up `apropos` output badly.  I'm only aware of one legitimate
+   counterexample, the Intercal compiler "oo, ick", which no longer appears
+   to be known by that name anyway; let me know if there are any others.
+ * `man` now discards `stderr` from formatting subprocesses when outputting
+   to a pager, to avoid visual corruption from any error messages.
+ * If the `MAN_KEEP_FORMATTING` environment variable is set to any non-empty
+   value, then `man` will preserve formatting characters in its output even
+   when standard output is not a terminal.  This may be useful for programs
+   such as `pinfo` that call `man` and can interpret its formatted output.
+ * Setting `NOCACHE` in the configuration file now prevents `man` from ever
+   creating cat pages automatically.
+ * `apropos` now accepts the `--and` option to display only items that match
+   all the supplied keywords.
+
+man-db 2.4.4 (12 February 2007)
+===============================
+
+man-db is now revision-controlled using
+[bzr](https://bazaar.canonical.com/).  See `docs/HACKING` for the location
+of the archive (including all CVS history, imported by Canonical).
+
+Fixes:
+
+ * SECURITY: Fix a buffer overrun if using `-H` and the designated web
+   browser (argument to `-H` or `$BROWSER`) contains multiple `%s`
+   expansions.  This is CVE-2006-4250.
+ * Ignore `SIGINT` and `SIGQUIT` while running subprocesses, so that typing
+   Ctrl-C doesn't kill `less` (broken in 2.4.3).
+ * Similarly, ignore `SIGPIPE` in subprocesses.
+ * Various fixes to `SIGCHLD` handling in pipeline library, preventing
+   "waitpid failed: No child processes" errors.
+ * Skip `exec` in configuration file commands (perhaps left over from old
+   installations), which the pipeline execution library cannot handle
+   directly.
+
+Improvements:
+
+ * Add support for Chinese in the `--enable-mb-groff` case.
+ * `lexgrog` now handles pages with multiple descriptions more usefully, by
+   displaying one description per output line.
+
+man-db 2.4.3 (3 July 2005)
+==========================
+
+Fixes:
+
+ * Avoid problems creating databases on systems with badly broken clocks set
+   before the Unix epoch.
+ * Fix detection of decompression programs, so that `man` doesn't attempt to
+   execute man pages when it doesn't have a corresponding decompression
+   program.
+
+Improvements:
+
+ * `apropos` and `whatis` now accept a `--section` option to restrict their
+   search to a particular manual section.
+ * The pipeline execution library is now used for most calls to external
+   programs, avoiding use of the shell.
+ * When `stdout` is not a terminal, man pages will be formatted in plain
+   text without the use of backspace or ANSI formatting characters.
+ * When invoking `apropos` (`man -k`) or `whatis` (`man -f`) as external
+   programs, `man` now only passes through command-line options understood
+   by the respective programs.
+ * Improve handling of locales with versions and/or modifiers.
+ * Add support for Croatian, Galician, Indonesian, Slovak, and Turkish
+   pages.
+ * man-db may now be built to use Berkeley DB version 4 (`--with-db=db4`).
+
+Compatibility notes:
+
+ * Setting the line length of manual pages now requires `groff` 1.18 or
+   later.
+
+man-db 2.4.2 (20 September 2003)
+================================
+
+Fixes:
+
+ * SECURITY: Fix a number of buffer overruns in configuration file handling,
+   ultimate source location, and `MANPATH` processing.  This is CVE
+   CAN-2003-0620.
+ * SECURITY: Restrict the use of the `DEFINE` directive in `~/.manpath` to
+   code running with dropped privilege.  Previously, the `compressor`
+   variable could be used to run arbitrary code with raised privilege.  This
+   is CVE CAN-2003-0645.
+ * Make sure to initialize `mandata` structures to zero.  The uses of
+   uninitialized memory resulting from this had been leading to random
+   segfaults.
+ * Drop privileges in order to be able to read pages in non-world-readable
+   user manpaths while setuid.
+ * `man` can be built with `--disable-setuid` again.
+ * `man`'s locale support has been revamped.  The encoding of source manual
+   pages is no longer related to the encoding of the input passed to `*roff`
+   or to `*roff`'s terminal output device.  These frequently differ,
+   especially in UTF-8 locales but in other circumstances as well, and a
+   "just send 8-bit data" approach is no longer adequate.  If you are using
+   a version of `groff` with the Debian multibyte patch applied, pass the
+   `--enable-mb-groff` option to configure.
+ * When using GDBM, `accessdb` and `apropos` did not return database entries
+   in sorted order, since GDBM's key traversal interface is not
+   lexicographically ordered.  The database layer has been corrected to cope
+   with this.
+ * Directories found in strange places in manual hierarchies don't crash
+   `mandb`.
+
+Improvements:
+
+ * `man` now calls `mandb` to update databases rather than doing it itself.
+   This leaves cat pages as the sole remaining reason for `man` to be
+   setuid.
+ * The "undocumented" message is only displayed if a corresponding
+   executable is found on the `$PATH`.
+ * All programs that read `~/.manpath` now take a `-C` option to cause them
+   to read a different user configuration file instead.
+ * The `--enable-debug` option to `configure` has been removed.  man-db's
+   `Makefile`s now always calculate full dependencies for C files.
+ * `mandb` caches the contents of directories, significantly speeding up the
+   purging of obsolete entries.
+ * `mandb` now knows how to purge database entries corresponding to removed
+   stray cat pages.
+ * In addition, a pipeline execution library has been written, which will
+   make it possible to eliminate all or almost all use of the shell in a
+   future release.  Unfortunately, time pressures due to the security issues
+   above meant that the pipeline library was not well enough tested for use
+   in this release, so it is present but unused.  That will be the first
+   item for 2.4.3.
+
+man-db 2.4.1 (22 December 2002)
+===============================
+
+The man-db CVS repository has moved from sourceforge.net to
+savannah.nongnu.org.
+
+Fixes:
+
+ * Don't enter an infinite loop when the `SYSTEM` environment variable is
+   set.
+ * `man` doesn't segfault when trying to follow a broken symlink.
+ * `mandb` no longer corrupts databases when deleting entries that are part
+   of multi keys.
+ * Prevent a possible buffer overflow when encountering large multi keys.
+ * Man page names are escaped when globbing, so `[(1)` can now be found even
+   if the database is not up to date.
+ * Correct an `access()` check that led to `man -X -l -` producing no
+   output.
+ * `lexgrog` can now cope with man pages containing only a `.so` link.
+ * Manual hierarchies with a specific encoding are put into the search path
+   in the correct order.  A bug in `$LANGUAGE` handling had formerly meant
+   that `de` would take precedence over `de_DE.UTF-8`.
+
+Improvements:
+
+ * `man`'s behaviour when searching for page names that begin with a digit
+   has been made more intuitive, as has its treatment of section names that
+   are extensions of ones mentioned in the configuration file but are not
+   themselves explicitly named as sections.
+ * The default line length for pages formatted for terminal output has been
+   increased (reducing margin size) to match the default in `groff` 1.18.
+ * Proofread the manual.
+ * The `-w` flag to `man` has been changed to display the name of only the
+   source `nroff` file.  A `-W` flag has been introduced which displays the
+   name of the cat file as well.  If both flags are given to `man`, it will
+   behave as before.
+ * If `bzip2` is installed, pages compressed with `bzip2` can now be
+   displayed.
+ * Add support for displaying an additional message when no man page is
+   found, which can be used to direct users to a generic "undocumented"
+   page.
+ * The manual hierarchy layout will now be guessed where possible if an
+   explicit `--enable-mandirs` argument is not passed to `configure`.
+
+man-db 2.4.0 (26 June 2002)
+===========================
+
+I have changed the package name to man-db, as the underscore was awkward.
+
+Upgrading from version 2.3.x:
+
+ * The database format has changed slightly, so you will need to run `mandb
+   --create` after installing the new version to rebuild your databases from
+   scratch.  (Distribution packages should do this automatically for system
+   databases.)
+
+Fixes:
+
+ * The GNU `nroff` test in `configure` now works when `/bin/sh` is `ash`.
+ * When scanning pages for `NAME` sections, `lexgrog` and `mandb` no longer
+   accidentally eat the line after each occurrence of the no-op request `.`.
+ * `man --local` drops privileges throughout to avoid problems with
+   non-world-readable home directories.
+ * Newly created cat directories are `chown`ed to the `man` user when
+   running as root.
+ * `man --html` no longer creates its temporary file with raised privileges,
+   so that it now works with a setuid `man`.
+ * `man` detects preprocessors correctly when setuid.
+ * Various segfault fixes: explicitly null-terminate data returned by the
+   Berkeley DB library to avoid some rare crashes; don't reuse a freed
+   pointer in some cases of pages with multiple names; handle `MANPATH`s
+   containing `::` more safely.
+ * Correctly parse manual pages using DOS line-ending conventions.
+ * Work around a misfeature in Berkeley DB: it pauses for several seconds if
+   asked to read a zero-length database, on the assumption that somebody is
+   still writing the metadata page.  `man` is generally better off just
+   ignoring the database in this case.
+ * Work around corrupted databases in the case where the `nextkey` pointer
+   chain contains a loop.
+
+Improvements:
+
+ * `man` looks in the filesystem followed by the database, rather than the
+   other way round.  Unix filesystems are quite good databases for this
+   purpose, and the `man` database is only superior when looking up names
+   that don't have associated links in the filesystem.
+ * `apropos --wildcard --exact` makes sure wildcards match an entire
+   description or page name, unlike `apropos --wildcard` which may match on
+   word boundaries too.
+ * `man`'s page-searching code has been substantially rearranged, and now
+   only starts displaying pages when it has finished searching for
+   candidates.  This allows pages to be sorted more sensibly.
+ * Manual pages are formatted in UTF-8 if that is the current locale's
+   character set.  The `-E` option is now available to force a particular
+   encoding.  Note that some versions of (e.g.) `less` have problems
+   displaying UTF-8 in conjunction with backspace characters; `groff` 1.18
+   should alleviate this by using ANSI colour escapes instead.
+ * The `less` prompt string sets `-PM` as well as `-Pm`.
+ * Invoking `man` from within `less` now sets the correct page title in the
+   inner `less`.
+ * Unless the `--match-case` option is used, `man` will search for pages
+   case-insensitively.
+ * Update the mechanism for setting the line length so that it also works
+   with `groff` 1.18.
+ * The `-R` switch is added to the `less` prompt string, which is needed to
+   display the ANSI colour escapes generated by `groff` 1.18 correctly.
+ * The `$MANLESS` environment variable may be used to override the normal
+   creation of the `less` prompt string.
+ * Translation updates for French, German, and Spanish, and a new Catalan
+   translation.  See `man/THANKS`.
+
+man\_db-2.3.20 (7 September 2001)
+=================================
+
+Fixes:
+
+ * A typo in 2.3.19 caused character sets for many languages to be detected
+   incorrectly.  This especially affected multibyte languages.
+ * Long options in the environment variable `LESS` are handled correctly.
+ * When checking if cat pages need to be updated, check for different
+   timestamps rather than whether the cat page is newer, as otherwise we
+   were confused by tools like `tar` that preserve timestamps in their
+   archives.  Each cat page is now set to have the same mtime as its
+   corresponding man page.
+ * Look up the correct character set each time a page is displayed rather
+   than just the first time, in case pages in several different character
+   sets are viewed in a single session.
+ * `groff` requests are no longer assumed to be case-insensitive when
+   scanning for preprocessors, so for example `mdoc`'s `.Eq` request isn't
+   mistaken for the `.EQ` which introduces `eqn` commands.
+ * Escape arguments passed to the shell that might contain dangerous
+   characters.
+ * Avoid an infinite loop if the `LANGUAGE` environment variable is set but
+   empty.
+ * The `--create` option to `mandb` now implies `--no-purge`.
+ * Temporary files are handled with more secure permissions.
+
+Improvements:
+
+ * Use a variant of `mkstemp()` rather than `tempnam()`, to avoid classic
+   race conditions.  (I don't believe the races were usefully exploitable.)
+ * Tolerate `whatis` entries in a database that point to themselves.
+ * Detect more translations of the `NAME` section.
+ * Add examples of man pages written in POD and SGML.
+ * `lexgrog` is now installed in `/usr/bin` by default, with proper argument
+   parsing, an improved output format, and a man page.  It is expected to be
+   used by programs that need to validate man pages.
+ * The `-H` (`--html`) option to `man` is now compiled in by default, and
+   supports the BROWSER specification (as
+   [documented](http://www.tuxedo.org/~esr/BROWSER/) and
+   [amended](https://www.dwheeler.com/browse/secure_browser.html)).
+
+man\_db-2.3.19 (5 July 2001)
+============================
+
+Fixes:
+
+ * The user configuration file `~/.manpath` is no longer trusted when
+   deciding whether to drop privileges.  In the process, user cat directory
+   handling has been improved.
+ * Commands of the form `man -S "" foo` formerly emptied the list of
+   acceptable sections and then searched the database anyway, and commands
+   of the form `man -S ::: foo` segfaulted.  Both now use the standard list
+   of sections.
+ * The `HUP` and `TERM` signals are now handled better.
+ * `straycats` processing invokes `col -bx` rather than `col-bx`.
+ * The `root` user is now correctly allowed to update databases in system
+   manpaths.
+ * `apropos` and `whatis` no longer enter infinite recursion if a database
+   contains an entry pointing to itself.
+
+Improvements:
+
+ * When compiled with `--enable-setuid`, `man` and `mandb` can be installed
+   non-setuid.  In this mode, they will be unable to write cat pages in
+   system directories or to modify system databases, but will otherwise
+   operate correctly.  This allows a single binary package to support setuid
+   and non-setuid modes of operation.
+ * The ordering of manual sections is read from `SECTION` directives in the
+   configuration file rather than being hard-coded.
+ * The `MANDB_MAP` configuration file directive is documented more clearly.
+ * Multiple `whatis` entries separated by commas, break requests, and/or
+   paragraph requests are handled more intelligently.
+ * Fill control requests (`.nf` and `.fi`) cause `lexgrog` to assume a break
+   at each newline.
+ * Duplicate manpath entries (often generated in the course of national
+   language support) are removed, so that `man -a` works better.
+ * man\_db's binaries are installed unstripped by default.
+ * Since supporting certain layouts of manual page hierarchies causes
+   problems for others, the layout is now selectable via `configure`.  The
+   default is to try all layouts.
+ * `man` only does an on-the-fly update of the database caches when the
+   `--update` option is given.
+ * Manual pages are displayed with a line length appropriate to the current
+   terminal.  If a non-standard line length is used (i.e. the terminal is
+   not between 66 and 80 characters wide) then cat pages will not be saved.
+ * `mandb` tries to purge obsolete entries from its databases.  Using the
+   `--create` flag should now usually only be necessary in cases of database
+   corruption.
+
+man\_db-2.3.18 (14 May 2001)
+============================
+
+man\_db-2.3.18 is an interim release under new maintenance by Colin Watson,
+merging much of the work done by former maintainers (Graeme Wilford and
+Fabrizio Polacco).  It incorporates several years of changes made in the
+Debian GNU/Linux distribution's package of man\_db.
+
+Here are a few highlights, with the names of the maintainers responsible for
+them.  As I am documenting after the fact of other people's changes of a few
+years ago, I have undoubtedly missed a number of fixes and improvements; I
+promise to keep track of these as I go along in future.
+
+Fixes:
+
+ * Multiple security fixes, including better handling of temporary files, a
+   format string vulnerability fix, and more careful dropping of privileges
+   when running setuid.  [Fabrizio, Colin]
+ * Databases no longer disappear temporarily while they are being
+   regenerated.  [Fabrizio]
+ * Corrected handling of locale environment variables.  Setting several
+   colon-separated locales in `$LANGUAGE` also works now.  [Colin]
+ * `whatis` and `apropos` are more careful about the possibility of a
+   corrupted database.  [Fabrizio, Colin]
+
+Improvements:
+
+ * If `root` has private manual hierarchies, cat pages generated from them
+   are no longer chowned to a less-privileged user.  [Wilf]
+ * Rewrote configuration file handling, adding `DEFINE` directives to set
+   paths to external programs.  The configuration file is now called
+   `man_db.conf`.  [Wilf]
+ * Support FHS paths (`/usr/share/man` and `/var/cache/man`) in preference
+   to FSSTND paths (`/usr/man` and `/var/catman`).  [Fabrizio]
+ * Converted from `catgets` to GNU `gettext` for national language support.
+   [Fabrizio, Colin]
+ * Several new and improved localized message catalogues and translated man
+   pages.  [Fabrizio, Colin, other contributors]
+ * Added `accessdb` utility, which displays the contents of a manual page
+   database.  [Fabrizio]
+ * Added user configuration file `~/.manpath`, with the same syntax as the
+   global configuration file.  [Fabrizio]
+ * Leading or trailing colons in the `MANPATH` environment variable cause
+   the manpath derived from configuration files to be prepended or appended
+   respectively.  A double colon in the middle of the environment variable
+   causes the configuration file manpath to be inserted between the colons.
+   [Fabrizio]
+ * Added experimental `-H` and `-Thtml` options to take advantage of
+   `groff`'s new HTML driver.  [Fabrizio]
+ * `lexgrog` now scans manual pages to guess which preprocessors are needed.
+   [Fabrizio]
+ * Create cat directories on the fly if necessary.  [Fabrizio]
+ * Supply a wrapper which explicitly drops privileges to uid `man` if `man`
+   or `mandb` is run as root.  In the future, splitting out setuid functions
+   into a separate helper process may remove the need for this paranoia.
+   [Fabrizio]
+ * Add `--test` option to `mandb`, which merely reports errors in manual
+   page hierarchies rather than actually creating or updating a database.
+   [Fabrizio, Colin]
+ * Manual pages may now be symlinks outside the mantree.  This should pose
+   no significant security concerns, and utilities such as GNU stow create
+   such symlinks.  [Colin]
+ * Deprecate `whatis` references for `man`, and display a warning if
+   displaying a page relies on going through a `whatis` reference.  They
+   often lead to confusingly non-obviously-deterministic behaviour, and
+   guaranteeing that `man` will honour them even when the database is out of
+   date causes performance problems.  [Colin]
+
+man\_db-2.3.11 (21 September 1995)
+==================================
+
+ * The man\_db manual is bundled in source form.
+ * Components of `$PATH` not in the config file were checked for `man`
+   subdirectories.  Now they are also checked for `../man`.
+ * Untarring a new manual page (with a timestamp older than the relative cat
+   file) over the original did *not* cause `man`/`catman` to reformat the
+   replacement.  This is changed.  As a side effect, untarring an unchanged
+   man file over the original will also cause a reformat.
+
+man\_db-2.3.10 (13 July 1995)
+=============================
+
+Fixes:
+
+ * Global databases were not owned by setuid owner (if applicable).  As a
+   consequence only `mandb` could update the databases unless `man` was run
+   by superuser.  Stupid bug.
+ * The keyword passed to `apropos` _never_ matched the first word of any
+   whatis line.
+ * `FAVOUR_STRAYCATS` code (if enabled), did not work properly.
+ * `zsoelim` did not work as advertised.
+
+Improvements:
+
+ * `man` removes its temporary files upon abnormal termination.
+ * `apropos` does proper word matching rather than the fuzzy matching of
+   2.3.5.  E.g. supplying any of the keywords: `ld.so`, `a.out`, `dynamic`,
+   `linker` or `loader` will match the following entry:
+
+     ld.so (8)            - a.out dynamic linker/loader
+
+   whereas `a.out` and `loader` used to fail.
+
+ * `man`/`whatis`/`apropos` return with exit code 16 if manual page/file or
+   keyword is not matched.  Previously exit code 0 was used making it
+   difficult for callers to know if the lookup was successful.
+ * Addition of German message catalogue.
+ * `apropos` and `man -k` do POSIX specified regex matching rather than
+   keyword searches if the environment variable `POSIXLY_CORRECT` is
+   defined.
+ * Added glob-only support of native system manual hierarchies on HP-UX, OSF
+   and Solaris operating systems.  Improved the `whatis` parsing code to
+   cope with majority of HP-UX manual pages.
+ * Ported to NeXTstep.
+
+man\_db-2.3.5 (21 April 1995)
+=============================
+
+Added support for:
+
+ * Non-standard section names i.e. multi-character
+
+ * Compressed manual pages.
+
+   A new utility `zsoelim` is included to correctly handle `nroff` `.so`
+   requests that point to a file which has been compressed.
+
+ * Compressed stray cats.
+
+   By definition, stray cats are not re-creatable as they have no relative
+   source manual page.  As they may have non-default compression extensions
+   and may reside on read-only media, stray cats have the same compression
+   support as manual pages.
+
+ * FSSTND proposed "extension" support.
+
+   Specific package manual pages may be installed in the standard sections
+   but with a package-unique extension appended as in `exit(3tcl)` -
+   `../man/man3/exit.3tcl`.  Using the command `man -e tcl exit` would then
+   display an `exit` manual page with a `tcl` extension, if available.  Of
+   course, `man 3tcl exit` works as always.
+
+ * FSSTND proposed NLS man subdirectories of the form
+   `.../man/<locale>/man<sec>/`.
+
+ * NLS message catalogue hooks.
+
+   Provision has been made for the programs to emit their messages in a
+   language dependent form.
+
+ * `whatis` referred manual pages.
+
+   Some manual pages contain relevant information for commands or programs
+   that would not otherwise reference the page.  The `whatis` part of the
+   manual page is used to create virtual links to these pages by all of the
+   names mentioned within it.  Examples include names such as `.` and `:`
+   referencing the local shell manual page.
+
+ * `catman` utility, used to pre-format the manual pages into cat pages.
+
+ * Operating systems other than Linux.
+
+   man\_db has been reported to compile on the following platforms: Linux,
+   SunOS, Solaris, Ultrix, OSF, HP-UX, AIX, IRIX (although portability does
+   not extend to support of native manual tree structures on some of these
+   systems, e.g. HP-UX).
+
+ * Berkeley DB library routines.
+
+   This complements the support of both `gdbm` and `ndbm` which already
+   existed.  DB databases may be shared across platforms.
+
+ * `$MANOPTS` environment variable.
+
+   The environment variable `MANOPTS` may be set to any string in command
+   line option/argument format.  It is parsed by `man(1)` prior to its
+   actual command line.
+
+ * Per manual hierarchy cat directory locations.
+
+   It is possible to redirect your cat pages to other directories or even
+   other file systems.
+
+ * Per manual hierarchy `nroff`/`[tg]roff` format scripts.
+
+   Ability to create custom formatter scripts that are called by `man(1)` to
+   enable format/display of non-standard manual pages or manual pages
+   requiring a special macro package.
+
+ * Extension of `man -l`.
+
+   Arguments following `-l` are interpreted as local files requiring format
+   and display.  Extensions are:
+
+   - `man -l -` formats and displays `stdin`.
+   - `man -l foo.1.gz` decompresses, formats and displays `foo.1.gz`.
+
+ * Latin1 manual pages/choice of `nroff` output device.
+
+ * Viewing of ASCII manual pages formatted for a latin1 output device on a 7
+   bit ASCII terminal (`-7`).
+
+ * `whatis` and `apropos` utilities support regex and wildcard matching.
+
+ * `checkman`.
+
+   Shell script utility that will find and display duplicated manual pages
+   found across manual page hierarchies.
+
+ * `mkcatdirs`.
+
+   Shell script utility to create appropriate cat directories after
+   installation and setup.
+
+Conceptual improvements:
+
+ * Replacement of single database with multiple modular databases.  Easier
+   integration of additional information into the databases in the future.
+
+ * Both user and global databases share the same name `index.<db-type>`,
+   where `<db-type>` could be `bt`, `db`, or `pag` and `dir`.
+
+ * Databases contain `whatis` text.
+
+   `makewhatis` and text `whatis` databases are redundant, although `whatis`
+   and `apropos` will use the text `whatis` database for information if they
+   cannot read from a relevant index database.
+
+ * Straycats handled without need for 'placeholders'.
+
+ * Friendly `less(1)` prompt.
+
+   If `man(1)` uses `less(1)` as its pager (dependent on both static and
+   dynamic factors), the prompt is modified to suit the manual page being
+   displayed.  The modification performed is also changeable by the user.
+
+ * man\_db manual.
+
+   man\_db has a manual that covers the setup, maintenance and use of a
+   generic online manual page system.
+
+ * Modes of operation.
+
+   The man\_db utilities can be compiled with various modes of operation in
+   mind.  E.g. `man` can be stopped from updating databases and/or creating
+   cat files in situations where security is extremely important.  See the
+   man\_db manual for details.
+
+Speed improvements:
+
+ * Background compression/saving of cat files.
+
+   Cat files are compressed and saved in the background, whilst the user is
+   able to browse the formatted page directly.
+
+ * Merge of `straycats` and `makewhatis` into `mandb`.
+
+   While `mandb` has slowed, it now incorporates `makewhatis` and
+   `straycats` functionality and is much faster as a whole.  2.0a2 used
+   `grep`/`awk`, 2.2 used C regex and 2.3 now uses `lex` sourced C to strip
+   out the `whatis` information from the raw man or cat files.
+
+ * Berkeley DB support.
+
+   Provides lower database initialisation overhead as compared with `gdbm`.
+
+ * Extremely fast `whatis(1)` searches.
+
+   `whatis(1)` uses keyed database lookups to retrieve whatis strings for
+   standard (non regex/wildcard) searches.
+
+Fixes:
+
+ * Correct handling of `$MANSECT`.
+
+   The environment variable `MANSECT` is no longer ignored.
+
+ * Acknowledgement of `$MANPATH` order.
+
+   manpath elements are searched in the order specified.