Settings: update time zone strings on date change

If the user changes the date, most obvious case being from 1970, to a
current date, and the user's selected Locale's country time zones have
been changed (according to ICU), we must update the time zone strings in
the system.

Ref: CYNGNOS-453

Signed-off-by: Roman Birg <roman@cyngn.com>
(cherry picked from commit 926c3b0a50e521368628ef0d9975c99fa4cd3480)

Change-Id: I487c54cd4f933286c5004d24a3f8730ee2d4e4f6

1 files changed, 13 insertions, 0 deletions

diff --git a/src/com/android/settings/DateTimeSettings.java b/src/com/android/settings/DateTimeSettings.java
index 8a9e2ad..34753ef 100644
--- a/src/com/android/settings/DateTimeSettings.java
+++ b/src/com/android/settings/DateTimeSettings.java
@@ -40,9 +40,12 @@ import android.widget.TimePicker;
 
 import com.android.internal.logging.MetricsLogger;
 import com.android.settingslib.datetime.ZoneGetter;
+import libcore.icu.TimeZoneNames;
 
+import java.text.DateFormatSymbols;
 import java.util.Calendar;
 import java.util.Date;
+import java.util.Locale;
 
 public class DateTimeSettings extends SettingsPreferenceFragment
         implements OnSharedPreferenceChangeListener,
@@ -329,6 +332,16 @@ public class DateTimeSettings extends SettingsPreferenceFragment
         if (when / 1000 < Integer.MAX_VALUE) {
             ((AlarmManager) context.getSystemService(Context.ALARM_SERVICE)).setTime(when);
         }
+        updateLocaleStrings();
+    }
+
+    static void updateLocaleStrings() {
+        // If a device was boot up with date 1970 and then date changes to some later time,
+        // the wrong string might be cached if the country's zones have changed.
+        // See external/icu/icu4c/source/data/misc/metaZones.txt for complete mapping
+        TimeZoneNames.clearLocaleCache();
+        Locale locale = Locale.getDefault();
+        DateFormatSymbols.getInstance(locale).setZoneStrings(TimeZoneNames.getZoneStrings(locale));
     }
 
     /* package */ static void setTime(Context context, int hourOfDay, int minute) {