From 8b6a387b19ed64df00e297d4a4b80562bb8f2812 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Wed, 18 May 2022 10:27:15 -0700
Subject: [PROPOSED] Go back to 2021e Morocco rearguard workaround
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* ziguard.awk: In rearguard format, go back to the 2021e approach
for Morocco, which predicts perpetual DST after 2087-05-11, with
TZ='XXX-2<+01>-1,0/0,J365/23'.  Although perpetual DST may confuse
rearguard clients for timestamps after 2087 we don’t know of any
such clients, whereas we do know of problems with present-day
timestamps computed via java.util.TimeZone.getDSTSavings
https://docs.oracle.com/javase/8/docs/api/java/util/TimeZone.html#getDSTSavings--
when implemented via
com.android.i18n.timezone.ZoneInfoData.getLatestDstSavingsMillis
https://android.googlesource.com/platform/external/icu/+/master/android_icu4j/libcore_bridge/src/java/com/android/i18n/timezone/ZoneInfoData.java#686
Problem reported by Almaz Mingaleev in:
https://mm.icann.org/pipermail/tz/2022-March/031352.html
https://mm.icann.org/pipermail/tz/2022-March/031356.html
---
 ziguard.awk | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/ziguard.awk b/ziguard.awk
index 6856a49..6888c27 100644
--- a/ziguard.awk
+++ b/ziguard.awk
@@ -104,23 +104,13 @@ DATAFORM != "main" {
   }
   if (!vanguard && $1 == "Rule" && $2 == "Morocco" && 2019 <= $3) {
     if ($9 == "0") {
-      # Add a day, to insert an extra transition to work around a bug
-      # in Android's DST offset finding logic circa 2022.  See:
-      # https://mm.icann.org/pipermail/tz/2022-March/031352.html
-      # This does not affect the UTC offset, only the DST flag for that day.
-      last_std_date = $3 " " $6 " " ($7 + 1) "  " $8
       sub(/\t0\t/, "\t1:00\t")
     } else {
       sub(/\t-1:00\t/, "\t0\t")
     }
   }
   if (!vanguard && $1 == "1:00" && $2 == "Morocco" && $3 == "+01/+00") {
-    # This introduces a transition from 01:59:59 +00 to 03:00:00 +01
-    # with both times being standard (i.e., a change to standard UT offset).
-    # This is rearguard's way to approximate the actual prediction,
-    # which is that of an ordinary transition from DST to standard time.
-    sub(/1:00\tMorocco\t\+01\/\+00$/,
-	"0:00\tMorocco\t+00/+01\t" last_std_date "\n\t\t\t 1:00\t-\t+01")
+    sub(/1:00\tMorocco\t\+01\/\+00$/, "0:00\tMorocco\t+00/+01")
   }
 }
 
-- 
2.34.1