From 39812e6f72b4105e2aede217f1cec2b42224dea1 Mon Sep 17 00:00:00 2001
From: Yoshito Umaoka <y.umaoka@gmail.com>
Date: Fri, 18 Nov 2011 22:30:34 +0000
Subject: [PATCH] ICU-8943 Fixed NPE problem in RuleBasedTimeZone#getOffsets.

X-SVN-Rev: 30975
---
 .../com/ibm/icu/util/RuleBasedTimeZone.java   | 18 +++++++--
 .../dev/test/timezone/TimeZoneRuleTest.java   | 39 ++++++++++++++++++-
 2 files changed, 53 insertions(+), 4 deletions(-)

diff --git a/icu4j/main/classes/core/src/com/ibm/icu/util/RuleBasedTimeZone.java b/icu4j/main/classes/core/src/com/ibm/icu/util/RuleBasedTimeZone.java
index 83279ac91a6..24798214b1e 100644
--- a/icu4j/main/classes/core/src/com/ibm/icu/util/RuleBasedTimeZone.java
+++ b/icu4j/main/classes/core/src/com/ibm/icu/util/RuleBasedTimeZone.java
@@ -572,7 +572,7 @@ public class RuleBasedTimeZone extends BasicTimeZone {
      */
     private void getOffset(long time, boolean local, int NonExistingTimeOpt, int DuplicatedTimeOpt, int[] offsets) {
         complete();
-        TimeZoneRule rule;
+        TimeZoneRule rule = null;
         if (historicTransitions == null) {
             rule = initialRule;
         } else {
@@ -587,8 +587,10 @@ public class RuleBasedTimeZone extends BasicTimeZone {
                 if (time > tend) {
                     if (finalRules != null) {
                         rule = findRuleInFinal(time, local, NonExistingTimeOpt, DuplicatedTimeOpt);
-                    } else {
-                        // no final rule, use the last rule
+                    }
+                    if (rule == null) {
+                        // no final rules or the given time is before the first transition
+                        // specified by the final rules -> use the last rule
                         rule = (historicTransitions.get(idx)).getTo();
                     }
                 } else {
@@ -638,6 +640,16 @@ public class RuleBasedTimeZone extends BasicTimeZone {
         }
         start1 = finalRules[1].getPreviousStart(base, finalRules[0].getRawOffset(), finalRules[0].getDSTSavings(), true);
 
+        if (start0 == null || start1 == null) {
+            if (start0 != null) {
+                return finalRules[0];
+            } else if (start1 != null) {
+                return finalRules[1];
+            }
+            // Both rules take effect after the given time
+            return null;
+        }
+
         return start0.after(start1) ? finalRules[0] : finalRules[1];
     }
 
diff --git a/icu4j/main/tests/core/src/com/ibm/icu/dev/test/timezone/TimeZoneRuleTest.java b/icu4j/main/tests/core/src/com/ibm/icu/dev/test/timezone/TimeZoneRuleTest.java
index 4fb75f924fa..d2f627f10bc 100644
--- a/icu4j/main/tests/core/src/com/ibm/icu/dev/test/timezone/TimeZoneRuleTest.java
+++ b/icu4j/main/tests/core/src/com/ibm/icu/dev/test/timezone/TimeZoneRuleTest.java
@@ -1,6 +1,6 @@
 /*
  *******************************************************************************
- * Copyright (C) 2007-2010, International Business Machines Corporation and    *
+ * Copyright (C) 2007-2011, International Business Machines Corporation and    *
  * others. All Rights Reserved.                                                *
  *******************************************************************************
  */
@@ -1788,4 +1788,41 @@ public class TimeZoneRuleTest extends TestFmwk {
         }
         return true;
     }
+
+    // Test case for ticket#8943
+    // RuleBasedTimeZone#getOffsets throws NPE
+    public void TestT8943() {
+        String id = "Ekaterinburg Time";
+        String stdName = "Ekaterinburg Standard Time";
+        String dstName = "Ekaterinburg Daylight Time";
+
+        InitialTimeZoneRule initialRule = new InitialTimeZoneRule(stdName, 18000000, 0);
+        RuleBasedTimeZone rbtz = new RuleBasedTimeZone(id, initialRule);
+
+        DateTimeRule dtRule = new DateTimeRule(Calendar.OCTOBER, -1, Calendar.SUNDAY, 10800000, DateTimeRule.WALL_TIME);
+        AnnualTimeZoneRule atzRule = new AnnualTimeZoneRule(stdName, 18000000, 0, dtRule, 2000, 2010);
+        rbtz.addTransitionRule(atzRule);
+
+        dtRule = new DateTimeRule(Calendar.MARCH, -1, Calendar.SUNDAY, 7200000, DateTimeRule.WALL_TIME);
+        atzRule = new AnnualTimeZoneRule(dstName, 18000000, 3600000, dtRule, 2000, 2010);
+        rbtz.addTransitionRule(atzRule);
+
+        dtRule = new DateTimeRule(Calendar.JANUARY, 1, 0, DateTimeRule.WALL_TIME);
+        atzRule = new AnnualTimeZoneRule(stdName, 21600000, 0, dtRule, 2011, AnnualTimeZoneRule.MAX_YEAR);
+        rbtz.addTransitionRule(atzRule);
+
+        atzRule = new AnnualTimeZoneRule(dstName, 21600000, 3600000, dtRule, 2011, AnnualTimeZoneRule.MAX_YEAR);
+        rbtz.addTransitionRule(atzRule);
+
+        int[] expected = {21600000, 0};
+        int[] offsets = new int[2];
+        try {
+            rbtz.getOffset(1293822000000L /* 2010-12-32 19:00:00 UTC */, false, offsets);
+            if (offsets[0] != expected[0] || offsets[1] != expected[1]) {
+                errln("Fail: Wrong offsets: " + offsets[0] + "/" + offsets[1] + " Expected: " + expected[0] + "/" + expected[1]);
+            }
+        } catch (Exception e) {
+            errln("Fail: Exception thrown - " + e.getMessage());
+        }
+    }
 }
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2.40.0