Yet Another Shell

Construct valuelist & splitlist in expand_four_T

This refactoring slightly reduces pointer dereferences.

Don't insert redundant / in command -v (#40670)

The format string "%s/%s" was the root cause of the issue. We should not
insert any more slash if the parent directory pathname (the first %s)
ends with a slash.

Version 2.50

Update ja.po

Up version to 2.50

More tests on $LINENO

Export correct value of $LINENO (#39279)

Better placement of comment

Test using GitHub Actions

Revert "Remove j_nonotify"

This reverts commit e0400605ac29a42ceeed8bcf86fe628a53d67c56.

Commit e040060 mistakenly assumed that the j_nonotify flag had been used
only to prevent the job from being removed, but in reality also from
being reported when the -b shell option is enabled.

As a result of the commit, the job status was being reported redundantly
when a job exits after resumed by the "fg" built-in.

Fork inside exec_simple_command

Previously the exec_simple_command function required the finally_exit
argument to be true when executed for CT_EXTERNALPROGRAM. I don't think
this implicit precondition very intuitive because it effectively
nullifies the finally_exit parameter.

Starting from this commit we fork inside the exec_simple_command
function to allow the parameter to be false.

Optimize read when stdin is a regular file

POSIX requires that the shell do not read too much from the standard
input. For this reason reading from the standard input is not buffered
by default. Without buffering, the "read" syscall is called for each
byte to be read, which may degrade the performance of the shell.

After this commit, when the standard input is a regular file, the input
is buffered to improve the performance. After reading, the file
descriptor is repositioned so that it works as if there has been no
buffering.

Optimize process forking with pipefail

When the pipe-fail option is on, the shell needs to await not only the
last command of a pipeline but also other commands. Because of this, the
optimization of not forking an unnecessary process for the last command
was not applied when the option was on.

If there is only one command in the pipeline, however, the pipe-fail
option can be ignored and the optimization is applicable.

completion/set: Describe pipefail option consistently

Previously, the description for yash's pipefail option was different
from that for other shells for no reason.

sample yashrc: Warn on crontab -r

Some users accidentally remove their crontab by typing "crontab -r" when
they intend to edit it by "crontab -e". To prevent unrecoverable loss,
a wrapper function for the crontab command is now installed in the
sample yashrc.

completion/git-rebase: Support Git 2.24.0

Ignore empty key sequence in terminfo (#39741)

If an empty key sequence is in le_keycodes, the read_next function would
loop infinitely. Such a sequence should be ignored even if defined in
the terminfo database.

Patch contributed by hvdijk

Version 2.49

Suppress compile-time warning from clang 8

Up version to 2.49

Update ja.po

Make nounset option effective in arithmetic expansion

The nounset option should reject unset variables in arithmetic expansion
as well so that the user can get an error when they mistakenly used a
misspelled variable.

This will be a next POSIX requirement:
http://austingroupbugs.net/view.php?id=559

completion/rsync: Complete local pathnames

completion/git: Complete remote refs correctly

Japanese documentation for for-local option (#39372)

completion/set: Complete the for-local option (#39372)

Reorganize tests for for-local option (#39372)

Document the forlocal option as for-local (#39372)

Add the forlocal option (#39372)

Patch contributed by Martijn Dekker.

Expand ""$* to an empty string (#39280)

The words ""$*, ""$@, $*"", and $@"" should expand to an empty string
rather than nothing when there are no positional parameters.