Release 1.0.10

Here is the tenth ksh 93u+m/1.0 bugfix release -- exactly two years
after 93u+m/1.0.0 and twelve years after 93u+. Unfortunately, we're
not done fixing bugs yet, but progress continues steadily.

Main changes between ksh 93u+m/1.0.9 and 93u+m/1.0.10:

- Fixed a serious and longstanding bug in the arithmetic subsystem
  that was triggered on non-Intel processors (such as ARM): any
  division of an integer by a negative integer threw a spurious
  "divide by zero" error.

- Fixed a regression where a broken pipe signal (SIGPIPE), when
  occurring in a pipe construct within a subshell, caused incorrect
  signal handling in the parent/main shell, in some cases causing a
  script to abort.

- Fixed a bug where printf %T, after having printed the time in UTC
  once with the TZ variable set to "UTC", would always print the
  time in UTC from then on, even if the TZ variable was changed to
  another time zone.

- The history expansion character ('!' by default) is now not
  processed when immediately following '${'. This makes it psosible
  to use expansion syntax like ${!varname} and ${!prefix@} on the
  interactive command line with the histexpand option on; these no
  longer trigger an "event not found" error.

- The shell is now capable of handling more than 32767 simultaneous
  background jobs, subject to system limitations.

Release 1.0.9

Here is the ninth ksh 93u+m/1.0 bugfix release.

Main changes between ksh 93u+m/1.0.8 and 93u+m/1.0.9:

- Android/Termux is now a supported platform. Build dependencies:
  binutils, clang, getconf. Runtime dependencies (optional):
  ncurses-utils, getconf.
- Reintroduced support for building a dynamically linked
  ksh(1)/shcomp(1), with libast, libdll, libcmd, and libshell
  available to other programs as dynamic libraries. 'bin/package
  install /your/basepath' will install development headers. The
  dynamically linked version is built in a 'dyn' subdirectory;
  there are no changes to the statically linked version. Dynamic
  linking is currently tested and supported on Linux, Android,
  macOS, all the BSDs, illumos, Solaris, QNX, and Haiku.
- On systems where the external printf(1) utility supports
  deprecated pre-POSIX syntax for formatters starting with '-', ksh
  now adapts its built-in printf to match, for compatibility with
  system scripts. However, ksh's built-in printf options such as -v
  or --man are not affected.
- Fixed a regression in the 'printf' built-in, introduced in
  93u+m/1.0.5, where each instance of '\0' or '%Z' in the format
  operand caused a string argument to be incorrectly skipped.
- Fixed a regression, introduced in 93u+m/1.0.5, in ordinal
  specifiers in 'printf %T' date specifications. For example,
        printf '%(%F)T\n' '4th tuesday in march 2016'
  wrongly printed '2016-04-09' and now again correctly prints
  '2016-03-22'.
- Fixed a regression of 'return' within traps, reintroduced in
  93u+m/1.0.8 after being fixed in 93u+m/1.0.0. The regression
  caused a 'return' or 'exit' with no arguments to assume the
  before-trap exit status instead of that of the last-run command.
  This broke the shipped 'autocd' function.
- Fixed a longstanding bug in shell arithmetic: the representation
  of negative integers with a base other than 10 was incorrectly
  treated as unsigned long. For example,
        typeset -i16 n=-12; echo $n
  now correctly outputs '-16#c' and no longer ouputs
  '16#fffffffffffffff4'.
- Fixed a bug, introduced in ksh93q+ 2005-05-22, that stopped an
  append assignment from working together with a declaration
  command. For example, 'typeset var+=value' or 'export var+=value'
  now again work as expected.
- Fixed a longstanding bug where the default terminal width for
  typeset -L, -R, or -Z, if not given, was miscalculated for
  multibyte or control characters.
- Fixed: expansions of name references in loops were incorrectly
  treated as invariant so they yielded the wrong values.
- If a .get or .getn discipline function is set for a variable, it
  is no longer incorrectly triggered when performing an arithmetic
  assignment on that variable; only the .set discipline is now
  triggered (as documented).
- Many other bug fixes (see the NEWS file).

Release 1.0.8

Happy new year! Here is the eighth ksh 93u+m/1.0 bugfix release.

Main changes between ksh 93u+m/1.0.7 and 93u+m/1.0.8:

- Fixed a regression in the behavior of 'exit' in a trap action.
  The exit status used when no argument is given to 'exit' is now
  once again the exit status of the last command executed *before*
  the trap action.
- Fixed a race condition, introduced in 1.0.7, that occurred on
  some systems when running an external command with a standard
  output redirection from a command substitution.
- Fixed an init-time crash on failure to trim the shell command
  history file due to a non-writable parent directory; ksh now
  prints a warning instead.
- The 'kill' built-in command now correctly refuses to issue
  SIGSTOP to the shell's own process if the shell is a login shell.

Release 1.0.7

Here is the seventh ksh 93u+m/1.0 bugfix release. It fixes a hang
in command substitutions when combined with 'exec' and certain
redirections.

Main changes between ksh 93u+m/1.0.6 and 93u+m/1.0.7:

- Fixed a hang in command substitutions (introduced in 93u+m/1.0.0)
  that was triggered when redirecting standard output within a
  command substitution, in combination with other factors. E.g.,
  the following no longer hangs:
	{ v=$(redirect 2>&1 1>&9); } 9>&1
- Fixed a crash on trying to append an indexed array value to an
  unset name reference, e.g.: nameref unsetref; unsetref+=(foo
  bar). This now produces a "removing nameref attribute" warning
  before performing the assignment.
- Fixed: assignments like name=(...) to arrays did not preserve the
  array and variable types; similarly, assigning an empty set () to
  a compound indexed array caused the -C attribute to be lost.
- Fixed incorrect rejection of the tab key while reading input
  using the 'read' built-in command.
- Fixed a bug in printf %T: when using dates and times in the past,
  time zones for the present were incorrectly used, ignoring
  historical changes.

Release 1.0.6

Sooner than expected after the fifth, here is the sixth ksh
93u+m/1.0 bugfix release. 93u+m/1.0.5 brought a wide range of
bugfixes and robustness enhancements, but also introduced a serious
regression in pathname expansion, so that previous release is
WITHDRAWN and should not be used.

Main changes between ksh 93u+m/1.0.5 and 93u+m/1.0.6:

- Fixed a serious regression in pathname expansion where quoted
  wildcard characters were incorrectly expanded if a pattern
  contains both a brace expansion and a variable expansion.
- Fixed a bug where the command to launch a full-screen editor
  (^X^E in emacs and 'v' in vi) could cause the wrong command line
  to be edited if two shell sessions share a .sh_history file.

Main changes between ksh 93u+m/1.0.4 and 93u+m/1.0.5:

- Fixed various bugs causing crashes.
- Fixed many bugs in the emacs and vi line editors, in command
  completion, and in file name completion.
- Fixed various bugs in the handling of quotes, backslash escapes
  and braces when processing shell glob patterns (e.g. in pathname
  expansion and 'case').
- ksh now throws a panic and exits if a read error (such as an I/O
  error) occurs while trying to read the next command(s) from a
  running script.
- Fixed many bugs in 'printf' and 'print -f' built-in commands,
  including:
  . Multiple bugs causing incorrect output for relative date
    specifications, e.g., printf %T\\n 'exactly 20 months ago' now
    outputs a correct result.
  . More printf bugs with mix and match of % and %x$.
  . A data corruption bug when using %B with 'printf -v varname'.
  . A bug causing double evaluation of arithmetic expressions.
- Fixed a bug where 'unset -f commandname', executed in a subshell,
  hides any built-in command by the same name for the duration of
  that subshell.
- Fixed ${var/#/string} and ${var/%/string} (with anchored empty
  pattern) to work as on mksh, bash and zsh; these are no longer
  ineffective.
- Fixed incorrect result of array slicing ${array[@]:offset:length}
  where 'length' is a nested expansion involving an array.
- Command names can now end in ':' as they can on other shells.
- Fixed a spurious syntax error in compound assignments upon
  encountering a pair of repeated opening parentheses '(('.
- Fixed spurious syntax error in ${parameter:offset:length}: the
  arithmetic expressions 'offset' and 'length' may now contain the
  operators ( ) & |.
- Fixed a parsing bug in the declaration of .sh.math.* arithmetic
  functions.
- Fixed nameref self-reference loop detection for more than two
  namerefs.
- Several improvements to the POSIX compatibility mode.
- Many more minor and/or esoteric bugfixes.

Release 1.0.4

Main changes between 1.0.3 and 1.0.4:

- Fixed multiple scoping-related bugs in the += additive assignment
  operator.
- A number of crashing bugs have been fixed.
- Various fixes for the Haiku operating system, notably 'ulimit -a'
  now works.
- Fixed the expansion of out-of-range \n back references in the
  string part of ${parameter//pattern/string}. For example:
	v=AB; echo "${v/@(A)B/\0:\1:\2}"
  now yields 'AB:A:' instead of 'AB:A:\2'.
- Fixed quoted '!', '^' and '-' within [bracket] expressions in
  glob patterns; single or double quotes failed to disable their
  operator behaviour.
- Fixed a bug introduced on 2021-04-04 that incorrectly allowed
  'typeset' to turn off the readonly and export attributes on a
  readonly variable.
- In the emacs line editor, the Ctrl+R reverse-search prompt is
  now visually distinct from a literal control character ("^R: "
  instead of "^R").
- In the vi line editor, fixed the behaviour of 'C', 'c$' and 'I'
  to be consistent with standard vi(1) and with Bolsky & Korn
  (1995, p. 121).
- Aliases for many GNU long options have been added to the
  /opt/ast/bin built-in commands. Additionally, 'kill -s' now has
  a --signal long option alias compatible with the util-linux
  option.
- Backported support for 'print -u p' from ksh 93v- for
  compatibility with scripts written for 93v-/ksh2020 (this is
  equivalent to 'print -p').

Release 1.0.3

This point release mainly fixes the following:
- A bug in history expansion (set -H) where any use of the history
  comment character caused processing to be aborted as if it were
  an invalid history expansion. Affected e.g. 'echo ${#v}'.
- A bug in command line options processing that caused short-form
  option equivalents on some built-in commands to be ignored after
  one use, e.g., the new read -a equivalent of read -A.
- Ksh freezing or using excessive memory if HISTSIZE is assigned a
  pathologically large value.
- A bug that caused ksh in the vi editor mode to crash or produce
  invalid completions if ESC = was used at the beginning of a line.

Release 1.0.2 (re: cd06386)

This release fixes the interactive shell crashing when one of the
predefined aliases (currently 'history' and 'r') is redefined,
whether from a profile/kshrc script or manually. This crash
occurred in two scenarios:

1. when redefining and then unsetting a predefined alias;

2. when redefining a predefined alias and then executing a shell
   script that does not begin with a #! path.

Both are fixed now.

Revert buggy exec optimisation (re: d6c9821)

As of 2022-06-18, ksh 93u+m is not capable of being used as /bin/sh
while building GNU binutils. The execution of some of its build
system's dot scripts is incorrectly aborted as an external 'sed'
command is execve(2)'d without forking. This means that incorrect
exec optimization was happening.

Unfortunately I have not been able to derive a minimal reproducer
of the problem yet because the GNU binutils build scripts are very
complex. Pending further research, the optimisation is reverted.
Even if a way to make it work is found, it will not be reintroduced
to the 1.0 branch.

Thanks to @atheik for finding the problem and identifying the
commit that introduced it.

Resolves: ksh93#507

Release 93u+m/1.0.0

 _        _        ___ _____                          ___   ___   ___
| | _____| |__    / _ \___ / _   _   _   _ __ ___    / / | / _ \ / _ \
| |/ / __| '_ \  | (_) ||_ \| | | |_| |_| '_ ` _ \  / /| || | | | | | |
|   <\__ \ | | |  \__, |__) | |_| |_   _| | | | | |/ / | || |_| | |_| |
|_|\_\___/_| |_|    /_/____/ \__,_| |_| |_| |_| |_/_/  |_(_)___(_)___/

It may have taken exactly a decade, but here we are... a proper new
ksh release. :) Many thanks to all contributors for their hard work!
Compared to an unpatched 93u+, this release has roughly a thousand
bugs fixed. It incorporates a fair number of enhancements as well.

Not all known bugs have been worked out yet; see the TODO file. Let's
hope this release will rekindle interest and attract more bug hunters.

This commit also makes some very minor fixes in comments. Notable:
src/cmd/ksh93/sh/arith.c: sh_strnum():
- Update a security-related comment. As of b48e5b3, evaluating
  untrusted arithmetic expressions from the environment should no
  longer cause CVE-2019-14868. But let's keep disallowing it anyway.

Resolves: ksh93#491