CVS commit: src/lib/libc/time

["Christos Zoulas" <christos%netbsd.org@localhost>]

Module Name:    src
Committed By:   christos
Date:           Fri Oct 19 23:05:35 UTC 2018

Modified Files:
        src/lib/libc/time: CONTRIBUTING Makefile NEWS README ctime.3 difftime.c
            localtime.c private.h strftime.3 strftime.c theory.html tz-art.html
            tz-how-to.html tz-link.html tzfile.5 tzselect.8 tzselect.ksh
            tzset.3 version zdump.8 zdump.c zic.8

Log Message:
Update to 2018f:

  Changes to code

    zic now always generates TZif files where time type 0 is used for
    timestamps before the first transition.  This simplifies the
    reading of TZif files and should not affect behavior of existing
    TZif readers because the same set of time types is used; only
    their internal indexes may have changed.  This affects only the
    legacy zones EST5EDT, CST6CDT, MST7MDT, PST8PDT, CET, MET, and
    EET, which previously used nonzero types for these timestamps.

    Because of the type 0 change, zic no longer outputs a dummy
    transition at time -2**59 (before the Big Bang), as clients should
    no longer need this to handle historical timestamps correctly.
    This reverts a change introduced in 2013d and shrinks most TZif
    files by a few bytes.

    zic now supports negative time-of-day in Rule and Leap lines, e.g.,
    "Rule X min max - Apr lastSun -6:00 1:00 -" means the transition
    occurs at 18:00 on the Saturday before the last Sunday in April.
    This behavior was documented in 2018a but the code did not
    entirely match the documentation.

    localtime.c no longer requires at least one time type in TZif
    files that lack transitions or have a POSIX-style TZ string.  This
    future-proofs the code against possible future extensions to the
    format that would allow TZif files with POSIX-style TZ strings and
    without transitions or time types.

    A read-access subscript error in localtime.c has been fixed.
    It could occur only in TZif files with timecnt == 0, something that
    does not happen in practice now but could happen in future versions.

    localtime.c no longer ignores TZif POSIX-style TZ strings that
    specify only standard time.  Instead, these TZ strings now
    override the default time type for timestamps after the last
    transition (or for all time stamps if there are no transitions),
    just as DST strings specifying DST have always done.

    leapseconds.awk now outputs "#updated" and "#expires" comments,
    and supports leap seconds at the ends of months other than June
    and December.  (Inspired by suggestions from Chris Woodbury.)

  Changes to documentation

    New restrictions: A Rule name must start with a character that
    is neither an ASCII digit nor "-" nor "+", and an unquoted name
    should not use characters in the set "!$%&'()*,/:;<=>?@[\]^`{|}~".
    The latter restriction makes room for future extensions (a
    possibility noted by Tom Lane).

    tzfile.5 now documents what time types apply before the first and
    after the last transition, if any.

    Documentation now uses the spelling "timezone" for a TZ setting
    that determines timestamp history, and "time zone" for a
    geographic region currently sharing the same standard time.

    The name "TZif" is now used for the tz binary data format.

    tz-link.htm now mentions the A0 TimeZone Migration utilities.
    (Thanks to Aldrin Martoq for the link.)


To generate a diff of this commit:
cvs rdiff -u -r1.4 -r1.5 src/lib/libc/time/CONTRIBUTING \
    src/lib/libc/time/tz-how-to.html
cvs rdiff -u -r1.40 -r1.41 src/lib/libc/time/Makefile
cvs rdiff -u -r1.24 -r1.25 src/lib/libc/time/NEWS
cvs rdiff -u -r1.13 -r1.14 src/lib/libc/time/README
cvs rdiff -u -r1.59 -r1.60 src/lib/libc/time/ctime.3
cvs rdiff -u -r1.18 -r1.19 src/lib/libc/time/difftime.c
cvs rdiff -u -r1.112 -r1.113 src/lib/libc/time/localtime.c
cvs rdiff -u -r1.52 -r1.53 src/lib/libc/time/private.h
cvs rdiff -u -r1.33 -r1.34 src/lib/libc/time/strftime.3
cvs rdiff -u -r1.41 -r1.42 src/lib/libc/time/strftime.c
cvs rdiff -u -r1.3 -r1.4 src/lib/libc/time/theory.html
cvs rdiff -u -r1.1 -r1.2 src/lib/libc/time/tz-art.html \
    src/lib/libc/time/tz-link.html
cvs rdiff -u -r1.25 -r1.26 src/lib/libc/time/tzfile.5
cvs rdiff -u -r1.7 -r1.8 src/lib/libc/time/tzselect.8 \
    src/lib/libc/time/version
cvs rdiff -u -r1.17 -r1.18 src/lib/libc/time/tzselect.ksh \
    src/lib/libc/time/zdump.8
cvs rdiff -u -r1.38 -r1.39 src/lib/libc/time/tzset.3
cvs rdiff -u -r1.49 -r1.50 src/lib/libc/time/zdump.c
cvs rdiff -u -r1.29 -r1.30 src/lib/libc/time/zic.8

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.