Allow switching of timezone string to messages locale, too.

* adjust POSIX locale backend to redirect the timezone string
  through the messages/time-locale indirection

headers/private/libroot/locale/ICUTimeData.h

@@ -37,6 +37,8 @@ public:
 
 			const char*			GetLanginfo(int index);
 
+			const Locale&		ICULocaleForStrings() const;
+
 private:
 			status_t			_SetLCTimeEntries(const UnicodeString* strings,
 									char* destination, int entrySize,

src/system/libroot/add-ons/icu/ICUTimeConversion.cpp

@@ -123,7 +123,7 @@ ICUTimeConversion::TZSet(const char* timeZoneID, const char* tz)
 		} else {
 			UnicodeString icuString;
 			fTimeZone->getDisplayName(i == 1, TimeZone::SHORT,
-				fTimeData.ICULocale(), icuString);
+				fTimeData.ICULocaleForStrings(), icuString);
 			CheckedArrayByteSink byteSink(fDataBridge->addrOfTZName[i],
 				sizeof(fTimeZoneID));
 			icuString.toUTF8(byteSink);

src/system/libroot/add-ons/icu/ICUTimeData.cpp

@@ -69,19 +69,7 @@ ICUTimeData::SetTo(const Locale& locale, const char* posixLocaleName)
 		return result;
 
 	UErrorCode icuStatus = U_ZERO_ERROR;
-
+	DateFormatSymbols formatSymbols(ICULocaleForStrings(), icuStatus);
-	// check if the date strings should be taken from the messages-locale
-	// or from the time-locale (default)
-	const Locale* symbolsLocale = &fLocale;
-	char stringsValue[16];
-	fLocale.getKeywordValue("strings", stringsValue, sizeof(stringsValue),
-		icuStatus);
-	if (U_SUCCESS(icuStatus) && strcasecmp(stringsValue, "messages") == 0)
-		symbolsLocale = &fMessagesData.ICULocale();
-	else
-		icuStatus = U_ZERO_ERROR;
-
-	DateFormatSymbols formatSymbols(*symbolsLocale, icuStatus);
 	if (!U_SUCCESS(icuStatus))
 		return B_UNSUPPORTED;
 
@@ -270,6 +258,22 @@ ICUTimeData::GetLanginfo(int index)
 }
 
 
+const Locale&
+ICUTimeData::ICULocaleForStrings() const
+{
+	// check if the date strings should be taken from the messages-locale
+	// or from the time-locale (default)
+	UErrorCode icuStatus = U_ZERO_ERROR;
+	char stringsValue[16];
+	fLocale.getKeywordValue("strings", stringsValue, sizeof(stringsValue),
+		icuStatus);
+	if (U_SUCCESS(icuStatus) && strcasecmp(stringsValue, "messages") == 0)
+		return fMessagesData.ICULocale();
+	else
+		return fLocale;
+}
+
+
 status_t
 ICUTimeData::_SetLCTimeEntries(const UnicodeString* strings, char* destination,
 	int entrySize, int count, int maxCount)