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Diffstat (limited to 'NEWS')
| -rw-r--r-- | NEWS | 135 |
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@@ -1,5 +1,140 @@ News for the tz database +Release 2025c - 2025-12-10 14:42:37 -0800 + + Briefly: + Several code changes for compatibility with FreeBSD. + + Changes to past timestamps + + Baja California agreed with California’s DST rules in 1953 and in + 1961 through 1975, instead of observing standard time all year. + (Thanks to Alois Treindl.) + + Changes to build procedure + + Files in distributed tarballs now have correct commit times. + Formerly, the committer’s time zone was incorrectly ignored. + + Distribution products (*.asc, *.gz, and *.lz) now have + reproducible timestamps. Formerly, only the contents of the + compressed tarballs had reproducible timestamps. + + By default, distributed formatted man pages (*.txt) now use UTF-8 + and are left-adjusted more consistently. A new Makefile macro + MANFLAGS can override these defaults. (Thanks to G. Branden + Robinson for inspiring these changes.) + + Changes to code + + An unset TZ is no longer invalid when /etc/localtime is missing, + and is abbreviated "UTC" not "-00". This reverts to 2024b behavior. + (Problem and patch reported by Dag-Erling Smørgrav.) + + New function offtime_r, short for fixed-offset localtime_rz. + It is defined if STD_INSPIRED is defined. + (Patch from Dag-Erling Smørgrav.) + + tzset etc. are now more cautious about questionable TZ settings. + Privileged programs now reject TZ settings that start with '/', + unless they are TZDEFAULT (default "/etc/localtime") or + start with TZDIR then '/' (default "/usr/share/zoneinfo/"). + Unprivileged programs now require files to be regular files + and reject relative names containing ".." directory components; + formerly, only privileged programs did those two things. + These changes were inspired by similar behavior in FreeBSD. + On NetBSD, unprivileged programs now use O_REGULAR to check + whether a TZ setting starting with '/' names a regular file, + avoiding a minor security race still present elsewhere. + TZ strings taken from tzalloc arguments are now treated with + no less caution than TZ strings taken from the environment, as + the old undocumented behavior would have been hard to explain. + tzset etc. no longer use the ‘access’ system call to check access; + instead they now use the system calls issetugid, getauxval, + getresuid/getresgid, and geteuid/getegid/getuid/getgid (whichever + first works) to test whether a program is privileged. + Compile with -DHAVE_SYS_AUXV_H=[01] to enable or disable + <sys/auxv.h> which (if it defines AT_SECURE) enables getauxval, + and compile with -DHAVE_ISSETUGID=[01], -DHAVE_GETRESUID=[01], and + -DHAVE_GETEUID=[01] to enable or disable the other calls’ use. + + The new CFLAGS option -DTZ_CHANGE_INTERVAL=N makes tzset etc. + check for TZif file changes if the in-memory data are N seconds + old or more, and are derived from the TZ environment variable. + This is intended for platforms that want tzset etc. to reflect + changes to whatever file TZ selects (including changes to + /etc/localtime if TZ is unset). If N is negative (the default) + these checks are omitted; this is the traditional behavior. + + The new CFLAGS options -DHAVE_STRUCT_STAT_ST_CTIM=0 and + -DHAVE_STRUCT_TIMESPEC=0 port to non-POSIX.1-2008 platforms + that lack st_ctim and struct timespec, respectively. + + tzset etc. now treat ' ' like '_' in time zone abbreviations, + just as they treat other invalid bytes. This continues the + transition begun in release 96k, which removed spaces in tzdata + because the spaces break time string parsers. + + The new CFLAGS option -DTHREAD_PREFER_SINGLE causes tzcode + in single-threaded processes to avoid locks, as FreeBSD does. + This can save time in single-threaded apps. The threadedness + testing costs CPU time and energy in multi-threaded apps. + New options -DHAVE___ISTHREADED and -DHAVE_SYS_SINGLE_THREADED_H + can help configure how to test for single-threadedness. + + The new CFLAGS option -DTHREAD_RWLOCK uses read-write locks, as + macOS does, instead of mutexes. This saves real time when TZ is + rarely changing and many threads call tzcode simultaneously. + It costs more CPU time and energy. + + The new CFLAGS option -TTHREAD_TM_MULTI causes localtime to return + a pointer to thread-specific memory, as FreeBSD does, instead of + to the same memory in all threads. This supports unportable + programs that incorrectly use localtime instead of localtime_r. + This option affects gmtime and offtime similarly to localtime. + Because the corresponding storage is freed on thread exit, this + option is incompatible with POSIX.1-2024 and earlier. It also + costs CPU time and memory. + + tzfree now preserves errno, consistently with POSIX.1-2024 ‘free’. + + tzcode now uses mempcpy if available, guessing its availability. + Compile with -DHAVE_MEMPCPY=1 or 0 to override the guess. + + tzcode now uses strnlen to improve asymptotic performance a bit. + Compile with -DHAVE_STRNLEN=0 if your platform lacks it. + + tzcode now hand-declares unistd.h-provided symbols like getopt + if HAVE_UNISTD_H=0, not if HAVE_POSIX_DECLS=0. + + tzset etc. now have an experimental OPENAT_TZDIR option; + see Makefile and localtime.c for details. + + On platforms like GNU/Hurd that do not define PATH_MAX, + exceedingly long TZ strings no longer fail merely because they + exceed an arbitrary file name length limit imposed by tzcode. + + zic has new options inspired by FreeBSD. ‘-D’ skips creation of + output ancestor directories, ‘-m MODE’ sets output files’ mode, + and ‘-u OWNER[:GROUP]’ sets output files’ owner and group. + + zic now uses the fdopen function, which was standardized by + POSIX.1-1988 and is now safe to use in portable code. + This replaces its use of the older umask function, which + complicated maintenance. + + Changes to commentary + + The leapseconds file contains commentary about the IERS and NIST + last-modified and expiration timestamps for leap second data. + (Thanks to Judah Levine.) + + Commentary now also uses characters from the set –‘’“”•≤ as this + can be useful and should work with current applications. This + also affects data in iso3166.tab and zone1970.tab, which now + contain strings like “Côte d’Ivoire” instead of “Côte d'Ivoire”. + + Release 2025b - 2025-03-22 13:40:46 -0700 Briefly: |