Further testing found that it was incompatible with Ubuntu 12.04 glibc
so this feature requires redesign and more testing.
* Makefile (ZFLAGS): Remove comment about name and version info.
Make it an empty var instead.
* tzfile.5, tzfile.h: Remove description of meta-information.
* zic.8: Remove options -n and -o.
* zic.c: Don't include <stddef.h>.
(genoption, genoptions, genname, addgenoption, writevalue): Remove.
(usage, main, writezone): Remove support for -n and -o.
* tzfile.5: Be a bit more careful about wording for integers.
Use binary terminators for the byte strings, not newlines.
Add a size field. Terminate by another NUL. Mention where
future extensions are expected to go.
* zic.c (writezone): Implement this.
(addgenoption): Omit namelen check; no longer needed.
(writevalue): Remove.
* Makefile (ZFLAGS): Add a comment about how to enable meta-info.
* tzfile.5: Describe meta-information.
* zic.8: Document new options -n and -o, which cause zic to
generate meta-info.
* zic.c: Include <stddef.h>, for ptrdiff_t.
(genoption, genoptions, genname): New static vars.
(usage): Summarize new options.
(addgenoption, writevalue): New function.
(main, writezone): Add support for new options.
Also, improve the documentation and diagnostics in this area.
Suggested by Arthur David Olson in
<http://mm.icann.org/pipermail/tz/2013-September/020064.html>.
* tzfile.5, tzfile.h: Bump tzfile format to version 3.
* zic.8: Document -v better.
* zic.c (ZIC_VERSION): Bump from '2' to '3'.
(stringrule, stringzone, outzone): Report compatibility issues
more carefully, mentioning client dates.
Problem reported by Zefram in
<http://mm.icann.org/pipermail/tz/2013-September/020059.html>.
* localtime.c (tzparse): Elide simultaneous entries out of and
into DST if DST goes for an hour more than a year (actually, for
more than the DST offset more than a year). Since this
optimization can elide all entries, avoid looping forever looking
for entries that will never arrive. While we're at it, fix
another portability bug where the code assumed wraparound on
signed integer overflow.
* newtzset.3, tzfile.5: Mention that as an extension to POSIX,
if DST covers the entire year plus the DST offset, it's assumed to
be in effect all year. Give an example.
* zic.c (stringrule): Omit the "J" in January and February,
as this can save a byte or two in the output.
(rule_cmp): New function.
(stringzone): Do a better job of constructing the standard-time
abbreviation when there is perpetual DST. Defer to the new
stringrule to construct the times for perpetual DST.
Fix bug noted by Zefram, which caused a stray hour of standard
time to be inserted in an otherwise perpetual DST.
Previously, this code generated "WARST4WARST,J1/0,J365/24"
for the San Luis example; now it generates "WART4WARST,0/0,J365/25".
This implements a suggestion by Arthur David Olson.
Without this change, zic -v diagnoses problems with several zones
where it cannot compute a POSIX-equivalent TZ setting for time
stamps past 2038, which means these time stamps may be mishandled.
This entails a minor change to the binary tz file format, to allow
a minor extension to the POSIX TZ setting in the binary file,
instead of requiring a pure POSIX TZ setting. The zones fixed by
this change are America/Godthab, America/Santiago, Antarctica/Palmer,
Asia/Gaza, Asia/Hebron, Asia/Jerusalem, Pacific/Easter, and
Pacific/Fiji. The only zone that remains unfixed is
Asia/Tehran, which schedules clock transitions via the
Iranian calendar, something that even the extended TZ
setting cannot represent.
* localtime.c (getrule): Allow transition times to be signed.
* newtzset.3: Describe the extensions to POSIX TZ strings.
Some of these extensions (e.g., hours == 26) were already
implemented but were not documented. Give examples.
* tzfile.5: Document the relaxed restriction on the stored TZ
string; its hours component can be in the range -167..167 rather
than the POSIX-required 0..24. Refer to newtzset(5).
* zic.c (stringoffset): Allow hours to go up to 167.
(stringrule): Be willing to generate hours in the range -167
through 167.
In several places the code and documentation incorrectly used
"UTC" to describe time stamps that might precede the introduction
of UTC and for which UTC is therefore undefined. Change these
uses to "UT", as that's the correct term when talking about these
time stamps. Problem reported by Steve Allen in
<http://mm.icann.org/pipermail/tz/2013-September/019907.html>.
The major compatibility issue here is with 'zdump -v'; it'll now
output "UT" instead of the possibly-incorrect "UTC".
Many files change in minor ways in the commentary.
* zdump.c (show):
* zic.c (inzsub, addtype):
In output, say "UT" rather than "UTC", since the time stamp we're
talking about might precede the introduction of UTC.
* tz-link.htm: Prune no-longer-working URLs, update URLs that got
moved, sort a bit. The most-important casualty is the Norwegian
Meteorological Institute's web page for Summer time in Norway,
formerly at <http://met.no/met/met_lex/q_u/sommertid.html>: it's
no longer there and I can't find out where it moved to, if
anywhere.
* tzfile.5: Fix minor grammar problem.
