From 6dfa3a52d0768002ad0055df1a4d1bfb0c1575e7 Mon Sep 17 00:00:00 2001
From: Yoshito Umaoka <y.umaoka@gmail.com>
Date: Mon, 7 Nov 2011 16:51:49 +0000
Subject: [PATCH] ICU-8927 Avoid NPE when invalid system ID is specifed in
 TimeZone.countEquivalentIDs and getEquivalentID.

X-SVN-Rev: 30937
---
 .../core/src/com/ibm/icu/impl/ZoneMeta.java   | 50 ++++++++++---------
 .../icu/dev/test/timezone/TimeZoneTest.java   | 15 ++++++
 2 files changed, 41 insertions(+), 24 deletions(-)

diff --git a/icu4j/main/classes/core/src/com/ibm/icu/impl/ZoneMeta.java b/icu4j/main/classes/core/src/com/ibm/icu/impl/ZoneMeta.java
index f79eecfab69..56ffa5dd357 100644
--- a/icu4j/main/classes/core/src/com/ibm/icu/impl/ZoneMeta.java
+++ b/icu4j/main/classes/core/src/com/ibm/icu/impl/ZoneMeta.java
@@ -218,13 +218,15 @@ public final class ZoneMeta {
      */
     public static synchronized int countEquivalentIDs(String id) {
         int count = 0;
-        try {
-            UResourceBundle res = openOlsonResource(null, id);
-            UResourceBundle links = res.get("links");
-            int[] v = links.getIntVector();
-            count = v.length;
-        } catch (MissingResourceException ex) {
-            // throw away
+        UResourceBundle res = openOlsonResource(null, id);
+        if (res != null) {
+            try {
+                UResourceBundle links = res.get("links");
+                int[] v = links.getIntVector();
+                count = v.length;
+            } catch (MissingResourceException ex) {
+                // throw away
+            }
         }
         return count;
     }
@@ -249,25 +251,25 @@ public final class ZoneMeta {
      */
     public static synchronized String getEquivalentID(String id, int index) {
         String result = "";
-        int zoneIdx = -1;
-
         if (index >= 0) {
-            try {
-                UResourceBundle res = openOlsonResource(null, id);
-                UResourceBundle links = res.get("links");
-                int[] zones = links.getIntVector();
-                if (index < zones.length) {
-                    zoneIdx = zones[index];
+            UResourceBundle res = openOlsonResource(null, id);
+            if (res != null) {
+                int zoneIdx = -1;
+                try {
+                    UResourceBundle links = res.get("links");
+                    int[] zones = links.getIntVector();
+                    if (index < zones.length) {
+                        zoneIdx = zones[index];
+                    }
+                } catch (MissingResourceException ex) {
+                    // throw away
+                }
+                if (zoneIdx >= 0) {
+                    String tmp = getZoneID(zoneIdx);
+                    if (tmp != null) {
+                        result = tmp;
+                    }
                 }
-            } catch (MissingResourceException ex) {
-                // throw away
-                zoneIdx = -1;
-            }
-        }
-        if (zoneIdx >= 0) {
-            String tmp = getZoneID(zoneIdx);
-            if (tmp != null) {
-                result = tmp;
             }
         }
         return result;
diff --git a/icu4j/main/tests/core/src/com/ibm/icu/dev/test/timezone/TimeZoneTest.java b/icu4j/main/tests/core/src/com/ibm/icu/dev/test/timezone/TimeZoneTest.java
index ba2783d113e..b5ef8f4efb5 100644
--- a/icu4j/main/tests/core/src/com/ibm/icu/dev/test/timezone/TimeZoneTest.java
+++ b/icu4j/main/tests/core/src/com/ibm/icu/dev/test/timezone/TimeZoneTest.java
@@ -1019,6 +1019,21 @@ public class TimeZoneTest extends TestFmwk
                         ") returned \"" + outOfRangeID + "\", expected empty string");
             }
         }
+
+        // Ticket#8927 invalid system ID
+        final String[] invaldIDs = {"GMT-05:00", "Hello World!", ""};
+        for (String invld : invaldIDs) {
+            int nEquiv = TimeZone.countEquivalentIDs(invld);
+            if (nEquiv != 0) {
+                errln("FAIL: countEquivalentIDs(" + invld + ") returned: " + nEquiv
+                        + ", expected: 0");
+            }
+            String sEquiv0 = TimeZone.getEquivalentID(invld, 0);
+            if (sEquiv0.length() > 0) {
+                errln("FAIL: getEquivalentID(" + invld + ", 0) returned \"" + sEquiv0
+                        + "\", expected empty string");
+            }
+        }
     }
 
     public void TestCountries() {
-- 
2.40.0