Paul Eggert via tz wrote in
 <[email protected]>:
 |I recently discovered that since 2006, the ICU file 
 |icu4c/source/tools/tzcode/icuzones has had a line "Zone Etc/Unknown 0 - 
 |Unknown"[1]. Any POSIX-like system that feeds this line into 'zic' might 
 |run afoul of the recently-proposed TZDB guideline[2] that Etc/Unknown is 
 |reserved and is not used by TZDB. This is because the line will cause 
 |Etc/Unknown to be a valid timezone with UT offset zero and abbreviation 
 |"Unknown", so that, for example, tzalloc("Etc/Unknown") will succeed 
 |instead of failing.
 |
 |I don't think this is a practical problem, as I don't know of any 
 |platform that feeds that icuzones line into zic and thus makes 
 |"Etc/Unknown" a valid timezone. However, it might be helpful to add a 
 |comment to icuzones about the situation. Proposed ICU patch attached.
 |
 |I am cc'ing this to Markus Scherer (who added the line) and to Yoshito 

You actually had forgotten Markus Scherer.

 |Umaoka (who most recently updated icuzones), to give them a heads-up on 
 |the situation.
 |
 |[1]: 
 |https://github.com/unicode-org/icu/blob/main/icu4c/source/tools/tzcode/i\
 |cuzones#L17
 |[2]: 
 |https://lists.iana.org/hyperkitty/list/[email protected]/message/5QWH2DCQ6SLY6\
 |JFJTDMJQC2LYHTJKB7O/

 |From 69218353e5e544348c8c0b138e6ab9c2e63c40aa Mon Sep 17 00:00:00 2001
 |From: Paul Eggert <[email protected]>
 |Date: Tue, 10 Dec 2024 10:53:14 -0800
 |Subject: [PATCH] Comment that icuzones should not be fed to zic
 |
 |---
 | icu4c/source/tools/tzcode/icuzones | 4 ++++
 | 1 file changed, 4 insertions(+)
 |
 |diff --git a/icu4c/source/tools/tzcode/icuzones b/icu4c/source/tools/tzc\
 |ode/icuzones
 |index 940b0557acc..2a99c8645b9 100644
 |--- a/icu4c/source/tools/tzcode/icuzones
 |+++ b/icu4c/source/tools/tzcode/icuzones
 |@@ -11,6 +11,10 @@
 | # that are in CLDR and also include legacy ICU time zones originally
 | # in tz.alias for rataining backward compatibility.
 | 
 |+# This file is not intended for use by zic, the TZDB timezone compiler.
 |+# Feeding it to zic would define Etc/Unknown as a known, valid timezone,
 |+# whereas Etc/Unknown should stand for an unknown or invalid timezone.
 |+
 | # Add Etc/Unknown, defined by CLDR. Give it Etc/GMT behavior.
 | 
 | # Zone       NAME            GMTOFF  RULES   FORMAT
 |-- 
 |2.47.1
 |
 --End of <[email protected]>

--steffen
|
|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)
|
|And in Fall, feel "The Dropbear Bard"s ball(s).
|
|The banded bear
|without a care,
|Banged on himself for e'er and e'er
|
|Farewell, dear collar bear

Reply via email to