Canonicalize tz IDs when finding exemplar location

Canonicalize time zone IDs when looking up exemplar location.

ICU's canonical IDs are not guaranteed the same as IANA's.
Various data files (e.g. timezones.xml, tzdata,
time_zones_by_country.xml) are using IANA IDs. ICU's IDs
are often the same, but because they are guaranteed not to
change and IANAs are not there is some drift.

This fixes an issue with the settings picker for ICU IDs:

America/Buenos_Aires
Asia/Rangoon
Asia/Katmandu
Asia/Calcutta

Which are IANA's:

America/Argentina/Buenos_Aires
Asia/Yangon
Asia/Kathmandu
Asia/Kolkata

introduced by commit b4d003da66.

It could also influence some display names for
automatically-selected time zones outside of this list.

The issues was particularly noticeable in locales that
use non-ASCII scripts; ICU performs a fallback if the ID
isn't canonical and would transform and return the last
part of the ID (e.g. Buenos Aires, Yangon, Kathmandu,
Kolkata).

Bug: 36469833
Test: Manual testing in Japanese
Change-Id: I2febdbee58e474d251d0a33f2c8335664a74581f
(cherry picked from commit f92ad8a0190add07779ed454a0908dd3df83f4bd)

diff --git a/packages/SettingsLib/src/com/android/settingslib/datetime/ZoneGetter.java b/packages/SettingsLib/src/com/android/settingslib/datetime/ZoneGetter.java
index 4bfca9b..474de90 100644 (file)
--- a/packages/SettingsLib/src/com/android/settingslib/datetime/ZoneGetter.java
+++ b/packages/SettingsLib/src/com/android/settingslib/datetime/ZoneGetter.java
@@ -211,7 +211,16 @@ public class ZoneGetter {
         if (preferLongName) {
             displayName = getZoneLongName(timeZoneNames, tz, now);
         } else {
-            displayName = timeZoneNames.getExemplarLocationName(tz.getID());
+            // Canonicalize the zone ID for ICU. It will only return valid strings for zone IDs
+            // that match ICUs zone IDs (which are similar but not guaranteed the same as those
+            // in timezones.xml). timezones.xml and related files uses the IANA IDs. ICU IDs are
+            // stable and IANA IDs have changed over time so they have drifted.
+            // See http://bugs.icu-project.org/trac/ticket/13070 / http://b/36469833.
+            String canonicalZoneId = android.icu.util.TimeZone.getCanonicalID(tz.getID());
+            if (canonicalZoneId == null) {
+                canonicalZoneId = tz.getID();
+            }
+            displayName = timeZoneNames.getExemplarLocationName(canonicalZoneId);
             if (displayName == null || displayName.isEmpty()) {
                 // getZoneExemplarLocation can return null. Fall back to the long name.
                 displayName = getZoneLongName(timeZoneNames, tz, now);
@@ -325,4 +334,4 @@ public class ZoneGetter {
             }
         }
     }
-}
\ No newline at end of file
+}