Yet Another Shell

Disallow recursive xtrace (#46095)

Remove outdated references to removed functions

The `save_parse_state' has been removed since long ago.

Update exported $DIRSTACK value in pushd/popd

Ensure allexport applied to all assignments (#46011)

Previously, there were many call sites of `set_variable' and `set_array'
that failed to pass `shopt_allexport'. This commit modifies the two
functions so that they applies the option themselves.

Apply errexit & errreturn to for loop assignment error (#46052)

Ensure noclobber redirection terminate (#46053)

Remove unnecessary apply_errexit_errreturn call

This call was added in r3628 to handle redirection errors in compound
commands. Since r4130 split the function so simple and compound commands
are handled in separate functions, the call is not needed now.

Allow configuring predict style through the PS*P variable

Patch contributed by Thomas Vigouroux <thomas.vigouroux@protonmail.com>

Run tests about comments as POSIX sh

Skip unstable tests about stopping signals (#45760)

There are more parameter combinations we have missed to skip.

Prevent some tests from being suspended (#45760)

.github/workflows/c: Use latest actions/checkout

.github/workflows/c: Use stable apt command line

The "apt" utility is for interactive uses and its command line syntax is
subject to change. We should use "apt-get" for scripting purposes.

Also, we should update the cache before installation since the stale
cache may prevent apt from fetching the correct package.

configure: add -std=c99 conditionally (#45739)

Many users seem to try to override the default CC and/or CFLAGS without
knowing the effect of what they are doing. Our build configuration needs
a confirming C99 compiler, which may require a specific option to select
the language version. This commit adds a dynamic test that makes sure
the compiler is invoked with appropriate options.

Require $PATH search for substitutive built-ins

This commit recategorizes regular built-ins into substitutive built-ins
and extension built-ins in order to remove the use of the words "regular
built-ins," which have been used in a different meaning than mentioned
in POSIX.

To minimize the behavioral differences caused by enabling the POSIXly-
correct mode, substitutive built-ins now require a corresponding
external program when running them except for the "array" built-in which
now is an extension built-in and is completely ignored in the POSIXly-
correct mode.

Reject non-portable built-ins in POSIX mode (#43467)

To be more restrictive on non-portable features in the POSIX mode, yash
now refuses to execute built-ins listed as utilities with unspecified
results in POSIX XCU 2.9.1. The built-in category "semi-special" is
removed in favor of the new categories "mandatory" and "elective."

doc/ja: Fix translation of meta-variables

doc/ja: Remove reference to incorrect option

The break and continue built-ins do not have the interact option.

doc/ja/intro: Fix markup

Version 2.53

Up version to 2.53

configure: Avoid compiler warnings in getrlimit test

GCC 12 yields a warning when getrlimit from glibc 2.35 is called with a
second parameter being null. We should suppress the warning so the test
succeeds when compiled with the -Werror option.

configure: Avoid compiler warnings in ncurses test

Recent versions of ncurses (at least version 6.2) have some function
prototype declarations different in parameter types. Because of the
incompatible-type warning, some tests in "configure" fail when compiled
with the -Werror option. This commit rewrites the test so it does not
produce warnings when it should succeed.

Update po files

Remove branch arith-error

Avoid undefined behavior in arithmetic expansion (#45200)

Update README

Update documentation

arith: Detect error in bitwise shifting

arith: Detect overflow in division