Provide multilingual support of Kernel32Util.formatMessage()

Author: overpathz

contrib/platform/src/com/sun/jna/platform/win32/Kernel32Util.java

@@ -178,22 +178,43 @@ public static void closeHandle(HANDLE h) {
         }
     }
 
+    /**
+     * Format a message from a code.
+     *
+     * @param code The error code
+     * @return Formatted message in the default locale.
+     */
+    public static String formatMessage(int code) {
+        return formatMessage(code, 0, 0);
+    }
+
     /**
      * Format a message from the value obtained from
      * {@link Kernel32#GetLastError()} or {@link Native#getLastError()}.
      *
+     * <p>If you pass in zero, FormatMessage looks for a message for LANGIDs in the following order:</p>
+     * <ol>
+     *   <li>Language neutral</li>
+     *   <li>Thread LANGID, based on the thread's locale value</li>
+     *   <li>User default LANGID, based on the user's default locale value</li>
+     *   <li>System default LANGID, based on the system default locale value</li>
+     *   <li>US English</li>
+     * </ol>
+     *
      * @param code The error code
-     * @return Formatted message.
+     * @param primaryLangId The primary language identifier
+     * @param sublangId The sublanguage identifier
+     * @return Formatted message in the specified locale.
      */
-    public static String formatMessage(int code) {
+    public static String formatMessage(int code, int primaryLangId, int sublangId) {
         PointerByReference buffer = new PointerByReference();
         int nLen = Kernel32.INSTANCE.FormatMessage(
                 WinBase.FORMAT_MESSAGE_ALLOCATE_BUFFER
                 | WinBase.FORMAT_MESSAGE_FROM_SYSTEM
                 | WinBase.FORMAT_MESSAGE_IGNORE_INSERTS,
                 null,
                 code,
-                0, // TODO: // MAKELANGID(LANG_NEUTRAL,SUBLANG_DEFAULT)
+                WinNT.LocaleMacros.MAKELANGID(primaryLangId, sublangId),
                 buffer, 0, null);
         if (nLen == 0) {
             throw new LastErrorException(Native.getLastError());

contrib/platform/test/com/sun/jna/platform/win32/Kernel32UtilTest.java

@@ -159,6 +159,18 @@ public void testFormatMessageFromHR() {
         }
     }
 
+    public void testFormatMessageFromErrorCodeWithNonEnglishLocale() {
+        int errorCode = W32Errors.S_OK.intValue();
+        String formattedMsgInDefaultLocale = Kernel32Util.formatMessage(errorCode);
+        // primary and sub languages id's of the english locale, because it is present on most machines
+        String formattedMsgInEnglishLocale = Kernel32Util.formatMessage(errorCode, 9, 1);
+        if(AbstractWin32TestSupport.isEnglishLocale) {
+            assertEquals(formattedMsgInDefaultLocale, formattedMsgInEnglishLocale);
+        } else {
+            assertNotSame(formattedMsgInDefaultLocale, formattedMsgInEnglishLocale);
+        }
+    }
+
     public void testGetTempPath() {
         assertTrue(Kernel32Util.getTempPath().length() > 0);
     }