7094176: (tz) Incorrect TimeZone display name when DST not applicable / disabled

Reviewed-by: okutsu

src/windows/native/java/util/TimeZone_md.c

@@ -165,6 +165,7 @@ static int getWinTimeZone(char *winZoneName, char *winMapID)
     WCHAR *stdNamePtr = tzi.StandardName;
     DWORD valueSize;
     DWORD timeType;
+    int isVista;
 
     /*
      * Get the current time zone setting of the platform.
@@ -180,6 +181,7 @@ static int getWinTimeZone(char *winZoneName, char *winMapID)
     ver.dwOSVersionInfoSize = sizeof(ver);
     GetVersionEx(&ver);
     isNT = ver.dwPlatformId == VER_PLATFORM_WIN32_NT;
+    isVista = isNT && ver.dwMajorVersion >= 6;
 
     ret = RegOpenKeyEx(HKEY_LOCAL_MACHINE, WIN_CURRENT_TZ_KEY, 0,
                        KEY_READ, (PHKEY)&hKey);
@@ -202,8 +204,13 @@ static int getWinTimeZone(char *winZoneName, char *winMapID)
             ret = RegQueryValueExA(hKey, "DynamicDaylightTimeDisabled",
                                    NULL, &valueType, (LPBYTE) &val, &bufSize);
         }
+
         if (ret == ERROR_SUCCESS) {
-            if (val == 1) {
+            int daylightSavingsUpdateDisabledOther = val == 1 && tzi.DaylightDate.wMonth != 0;
+            int daylightSavingsUpdateDisabledVista = val == 1;
+            int daylightSavingsUpdateDisabled = isVista ? daylightSavingsUpdateDisabledVista : daylightSavingsUpdateDisabledOther;
+
+            if (daylightSavingsUpdateDisabled) {
                 (void) RegCloseKey(hKey);
                 customZoneName(tzi.Bias, winZoneName);
                 return VALUE_GMTOFFSET;
@@ -213,7 +220,7 @@ static int getWinTimeZone(char *winZoneName, char *winMapID)
         /*
          * Vista has the key for the current "Time Zones" entry.
          */
-        if (isNT && ver.dwMajorVersion >= 6) {
+        if (isVista) {
             valueType = 0;
             bufSize = MAX_ZONE_CHAR;
             ret = RegQueryValueExA(hKey, "TimeZoneKeyName", NULL,

test/java/util/TimeZone/DstTzTest.java

+/*
+ * Copyright (c) 2012 Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * Portions Copyright (c) 2012 IBM Corporation
+ */
+
+/* @test
+ * @bug 7094176
+ * @summary Incorrect TimeZone display name when DST not applicable and
+ * disabled
+ * @run main DstTzTest
+ */
+
+import java.util.TimeZone;
+
+/**
+ * Manaul steps:
+ * 1. In the Windows Date and Time Properties dialog, set the time zone to one that uses DST (e.g. Greenwich Mean Time).
+ * 2. Disable the 'Automatically adjust clock for Daylight Saving Changes' option.
+ * 3. Change the time zone to one that does not use DST (e.g. India Standard Time - (GMT+5:30) Chennai,Kolkata,Mumbai,New Delhi)
+ * 4. Compile and run the testcase
+ */
+public class DstTzTest {
+    public static void main(String[] args) throws Exception {
+        String expectedName = "India Standard Time";
+        String tzName = TimeZone.getDefault().getDisplayName();
+        System.out.println(tzName);
+
+        if (!expectedName.equals(tzName)) {
+            throw new Exception("Expected time zone name is " + expectedName + ", output is " + tzName);
+        }
+    }
+}