the new version of the code used to generate these tables forces a
newline every 256 entries, whereas at the time these files were
originally generated and committed, it only wrapped them at 80
columns. the new behavior ensures that localized changes to the
tables, if they are ever needed, will produce localized diffs. other
tables including hkscs were already committed in the new format.

binary comparison of the generated object files was performed to
confirm that no spurious changes slipped in.

If the syscall fails, errno must be set correctly for the caller.
There's no guarantee that the handlers registered with pthread_atfork
won't clobber errno, so we need to ensure it gets set after they are
called.

this implementation aims to match the baseline defined by rfc1468 (the
original mime charset definition) plus the halfwidth katakana
extension included in the whatwg definition of the charset. rejection
of si/so controls and newlines in doublebyte state are not currently
enforced. the jis x 0201 mode is currently interpreted as having the
yen sign and overline character in place of backslash and tilde; ascii
mode has the standard ascii characters in those slots.

assuming pointers obtained from malloc have some nonzero alignment,
repurpose the low bit of iconv_t as an indicator that the descriptor
is a stateless value representing the source and destination character
encodings.

the special case where mbrtowc returns 0 but consumed 1 byte of input
does not need to be considered, because the short-circuit for low
bytes already covered that case.

short-circuiting low bytes before the switch precluded support for
character encodings that don't coincide with ascii in this range. this
limitation affected iso-2022 encodings, which use the esc byte to
introduce a shift sequence, and things like ebcdic.

this is in preparation to support stateful conversion descriptors,
which are necessarily allocated and thus must be freed in iconv_close.
putting it in a separate TU will avoid pulling in free if iconv_close
is not referenced.

this change is made to avoid having assumptions about the encoding
spread out across the file, and to facilitate future change to a form
that can accommodate allocted, stateful descriptors when needed.

this commit should not produce any functional changes; with the
compiler tested the only change to code generation was minor
reordering of local variables on stack.

If AI_NUMERICSERV is specified and a numeric service was not provided,
POSIX mandates getaddrinfo return EAI_NONAME. EAI_SERVICE is only for
services that cannot be used on the specified socket type.

commit a6054e3c changed this function
not to take an argument, but the weak definition used by timer_create
was not updated to match.

reported by Pascal Cuoq.

s390 can use the generic ioctls definitions other than FIOQSIZE (like arm).

this fixes some missing ioctls and two incorrect ones:
TIOCTTYGSTRUCT and TIOCM_MODEM_BITS seem to be defined on frv
target only in linux.

statx number is allocated for microblaze in linux commit
f5ef419630e85e80284cd0256cb5a13a66bbd6c5

allows expanding the signal frame beyond the 4k reserved space.
new in linux commit 33f082614c3443d937f50fe936f284f62bbb4a1b

TCP_ULP is new in linux commit 734942cc4ea6478eed125af258da1bdbb4afe578
TCP_MD5SIG_EXT is new in 8917a777be3ba566377be05117f71b93a5fd909d

for getting/setting write lifetime hints fcntl commands were
added in linux commit c75b1d9421f80f4143e389d2d50ddfc8a28c8c35

added under _GNU_SOURCE || _BSD_SOURCE, since RWH_* life time
hints are not in the POSIX reserved namespace.

added for safe opening of peer end of pty in a mount namespace.
new in linux commit c6325179238f1d4683edbec53d8322575d76d7e2

SCM_TIMESTAMPING_PKTINFO is new in aad9c8c470f2a8321a99eb053630ce0e199558d6
SO_PEERGROUPS is new in 28b5ba2aa0f55d80adb2624564ed2b170c19519e

new syscall in linux commit 916cda1aa1b412d7cf2991c3af7479544942d121

syscall for i386 compat mode on x86_64 for non-x86_64 prctls.
new in linux commit 79170fda313ed5be2394f87aa2a00d597f8ed4a1

hwcap bits for armv8.3 extensions, added in linux commits
c8c3798d2369e4285da44b244638eafe446a8f8a
cb567e79fa504575cb97fb2f866d2040ed1c92e7
c651aae5a7732287c1c9bc974ece4ed798780544

new in linux commit 531b374834c891ae2abf800693074df35a7d1a36

SO_MEMINFO added in linux commit a2d133b1d465016d0d97560b11f54ba0ace56d3e
SO_INCOMING_NAPI_ID added in 6d4339028b350efbf87c61e6d9e113e5373545c9
SO_COOKIE added in 5daab9db7b65df87da26fd8cfa695fb9546a1ddb

statx was added in linux commit a528d35e8bfcc521d7cb70aaf03e1bd296c8493f
(there is no libc wrapper yet and microblaze and sh misses the number).

two new stats for SCM_TIMESTAMPING_OPT_STATS, added in linux commit
7e98102f489775d8c000884fca8a0d995ea688a9

new in linux commit 19f6d3f3c8422d65b5e3d2162e30ef07c6e21ea2

new in linux commit 69ae543969abeba48e04dd93277684c8c0895f3b

new hwcap bits were added in kernel commits
77c97b4ee21290f5f083173d957843b615abbff2
f92f5ce01ee6a6a86cbfc4e3b0d18529c302b1ea

added in linux commit 80f60e509a03ff9ff2bdbf9cd1e935c6360b8bd9

missing syscalls got allocated on microblaze.

linux commit 575b1967e10a1f3038266244d2c7a3ca6b99fed8 moved timerfd
apis to a new uapi header which showed musl was missing this flag.

min max mtu size definitions mostly for drivers.
new in linux commits a52ad514fdf3b8a57ca4322c92d2d8d5c6182485 and
d894be57ca92c8a8819ab544d550809e8731137b

added in linux commit 70ecc24841326396a827deb55c3fefac582a729d

for tcp timestamp control messages, new in linux commit
1c885808e45601b2b6f68b30ac1d999e10b6f606
and export time measurements via tcp_info, added in linux commit
efd90174167530c67a54273fd5d8369c87f9bd32

the resolution to Austin Group issue #411 defined new semantics for
the posix_spawn dup2 file action in the (previously useless) case
where src and dest fd are equal. future issues will require the dup2
file action to remove the close-on-exec flag. without this change,
passing fds to a child with posix_spawn while avoiding fd-leak races
in a multithreaded parent required a complex dance with temporary fds.

based on patch by Petr Skocik. changes were made to preserve the
80-column formatting of the function and to remove code that became
unreachable as a result of the new functionality.

commit 06fbefd1 (first included in
release 1.1.17) introduced this regression.

patch by Adrian Bunk. it fixes the regression in all cases, but
spuriously prevents use of the clz instruction on very old compiler
versions that don't define __ARM_ARCH. this may be fixed in a more
general way at some point in the future. it also omits thumb1 logic
since building as thumb1 code is currently not supported.

commit 8c4be3e2 was written to
preclude the GLOB_PERIOD extension from matching these directory
entries, but also precluded literal matches.

adjust the check that excludes . and .. to check whether the
GLOB_PERIOD flag is in effect, so that it cannot alter behavior in
cases governed by the standard, and also don't exclude . or .. in any
case where normal glob behavior (fnmatch's FNM_PERIOD flag) would have
included one or both of them (patterns such as ".*").

it's still not clear whether this is the preferred behavior for
GLOB_PERIOD, but at least it's clear that it can no longer break
applications which are not relying on quirks of a nonstandard feature.

execvpe stack-allocates a buffer used to hold the full path
(combination of a PATH entry and the program name)
while searching through $PATH, so at least
NAME_MAX+PATH_MAX is needed.

The stack size can be made conditionally smaller
(the current 1024 appears appropriate)
should this larger size be burdensome in those situations.

MAXADDRS was chosen not to need enforcement, but the logic used to
compute it assumes the answers received match the RR types of the
queries. specifically, it assumes that only one replu contains A
record answers. if the replies to both the A and the AAAA query have
their answer sections filled with A records, MAXADDRS can be exceeded
and clobber the stack of the calling function.

this bug was found and reported by Felix Wilhelm.