After patch 9d26b82, we don't provide recursive call protection anymore.
Therefore, to pass the test, we adjust the testcase by protecting on
caller and the testcase is to make sure the dtors is properly handled.

Reported by:    siva
Reviewed by:    kib
Approved by:    markj (mentor)
Fixes:  9d26b82826d9 ("libc: Fix dtor order in __cxa_thread_atexit")
MFC after:      2 weeks
Sponsored by:   The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D55893

We were saving SIGINT twice instead of SIGINT and SIGQUIT.

Also restore original order of operations (SIGINT then SIGQUIT), which
matches the order in which they're discussed in the POSIX description
of system(3).

MFC after:	1 week
Sponsored by:	Klara, Inc.
Fixes:		48368f702423 ("system(3): Address test robustness issue")

Don't assume that SIGINT and SIGQUIT are set to SIG_DFL at the start
of the test.  Instead, retrieve their current dispositions and verify
that they are restored at the end of the test.

MFC after:	1 week
Sponsored by:	Klara, Inc.
Reviewed by:	kevans
Differential Revision:	https://reviews.freebsd.org/D55709

Our manual page states that if given a null pointer, system() returns
non-zero if the shell is available and zero if it is not.  This is
consistent with the C standard's description of system(), but it is not
what we actually do.  What we actually do is always return non-zero, as
required by POSIX.

As the POSIX rationale explains, implementing the logic required by the
C standard does not violate POSIX, since a conforming system always has
a shell, therefore the logic will always return non-zero.

Since our libc is commonly used in non-conforming situations such as
chroots or thin jails, we should implement the full logic required by
the C standard.

MFC after:	1 week
Sponsored by:	Klara, Inc.
Reviewed by:	obiwac, bnovkov, kevans
Differential Revision:	https://reviews.freebsd.org/D55484

Replace the somewhat perfunctory NetBSD tests with our own.

MFC after:	1 week
Sponsored by:	Klara, Inc.
Reviewed by:	bnovkov, kevans
Differential Revision:	https://reviews.freebsd.org/D55482

Reviewed by:	alc, emaste
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D54365

If the locale's positive_sign and negative_sign values would both be
returned by localeconv() as empty strings, strfmon() shall behave as if
the negative_sign value was the string "-".

This occurs with the C locale.  The implementation previously assigned
"0" to sign_posn (parentheses around the entire string); now it assigns
it to "1" (sign before the string) when it is undefined (CHAR_MAX).

Austin Group Defect 1199[1] is applied, changing the requirements for
the '+' and '(' flags.

[1]: https://www.austingroupbugs.net/view.php?id=1199

Reviewed by:	kib
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D53913

According to the Open Group Base Specifications Issue 8[1], strfmon(3)
should return EINVAL when the '+' flag was included in a conversion
specification and the locale's positive_sign and negative_sign values
would both be returned by localeconv(3) as empty strings.

Austin Group Defect 1199[2] is applied, adding the [EINVAL] error.

[1]: https://pubs.opengroup.org/onlinepubs/9799919799/functions/strfmon.html
[2]: https://www.austingroupbugs.net/view.php?id=1199

Reviewed by:	kib
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D53912

Add tests for The Open Group Base Specifications Issue 8[1], Austin
Group Defect 1199[2].

Items marked with XXX represent an invalid output.  These items will be
fixed in subsequent commits.

Notice that an existing test is now considered invalid.

Our locale definitions do not include int_p_sep_by_space nor
int_n_sep_by_space[3].  Those will be addressed in a subsequent commit.
However, the CLDR project defines them as "0", which causes the output
to appear as "USD123.45".  If our locale definitions were to set the
international {n,p}_sep_by_space to "1", the output would display as the
expected "USD 123.45".

While here, use the SPDX license identifier and add my name to the
file.

[1]: https://pubs.opengroup.org/onlinepubs/9799919799/functions/strfmon.html
[2]: https://www.austingroupbugs.net/view.php?id=1199
[3]: https://unicode-org.atlassian.net/browse/CLDR-237

Reviewed by:	kib
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D53911

As pointed out in the PR and the article linked below, the switch to
insertion sort in the BSD qsort code is based on a misunderstanding of
Knuth's TAOCP and is actually a pessimization.  As demonstrated by the
added test, it is trivially easy to construct pathological input which
results in quadratic runtime.  Without that misguided optimization, the
same input runs in nearly linearithmic time.

https://www.raygard.net/2022/02/26/Re-engineering-a-qsort-part-3

PR:		287089
MFC after:	1 week
Reviewed by:	imp
Differential Revision:	https://reviews.freebsd.org/D51907