ICU-4611 Fix Japanese calendar calculation problem. Changed internal APIs to get default month/date of a calendar without updating calendar fields.

X-SVN-Rev: 24574

icu4c/source/i18n/calendar.cpp

@@ -2511,7 +2511,7 @@ int32_t Calendar::handleComputeJulianDay(UCalendarDateFields bestField)  {
     if(isSet(UCAL_MONTH)) {
         month = internalGet(UCAL_MONTH);
     } else {
-        month = getDefaultMonthInYear();
+        month = getDefaultMonthInYear(year);
     }
 
     int32_t julianDay = handleComputeMonthStart(year, useMonth ? month : 0, useMonth);
@@ -2523,7 +2523,7 @@ int32_t Calendar::handleComputeJulianDay(UCalendarDateFields bestField)  {
         if(isSet(UCAL_DAY_OF_MONTH)) {
             dayOfMonth = internalGet(UCAL_DAY_OF_MONTH,1);
         } else {
-            dayOfMonth = getDefaultDayInMonth(month);
+            dayOfMonth = getDefaultDayInMonth(year, month);
         }
         return julianDay + dayOfMonth;
     }
@@ -2678,13 +2678,13 @@ int32_t Calendar::handleComputeJulianDay(UCalendarDateFields bestField)  {
 }
 
 int32_t
-Calendar::getDefaultMonthInYear() 
+Calendar::getDefaultMonthInYear(int32_t /*eyear*/) 
 {
     return 0;
 }
 
 int32_t
-Calendar::getDefaultDayInMonth(int32_t /*month*/) 
+Calendar::getDefaultDayInMonth(int32_t /*eyear*/, int32_t /*month*/) 
 {
     return 1;
 }

icu4c/source/i18n/japancal.cpp

@@ -318,19 +318,17 @@ const char *JapaneseCalendar::getType() const
     return "japanese";
 }
 
-int32_t JapaneseCalendar::getDefaultMonthInYear() 
+int32_t JapaneseCalendar::getDefaultMonthInYear(int32_t eyear) 
 {
     UErrorCode status  = U_ZERO_ERROR;
     int32_t era = internalGetEra();
-    computeFields(status); // slow
-    int32_t year = getGregorianYear();
     // TODO do we assume we can trust 'era'?  What if it is denormalized?
 
-    int32_t month = GregorianCalendar::getDefaultMonthInYear();
+    int32_t month = 0;
 
     // Find out if we are at the edge of an era
 
-    if(year == kEraInfo[era].year) {
+    if(eyear == kEraInfo[era].year) {
         // Yes, we're in the first year of this era.
         return kEraInfo[era].month-1;
     }
@@ -338,15 +336,13 @@ int32_t JapaneseCalendar::getDefaultMonthInYear()
     return month;
 }
 
-int32_t JapaneseCalendar::getDefaultDayInMonth(int32_t month) 
+int32_t JapaneseCalendar::getDefaultDayInMonth(int32_t eyear, int32_t month) 
 {
     UErrorCode status  = U_ZERO_ERROR;
     int32_t era = internalGetEra();
-    computeFields(status); // slow
-    int32_t year = getGregorianYear();
-    int32_t day = GregorianCalendar::getDefaultDayInMonth(month);
+    int32_t day = 1;
 
-    if(year == kEraInfo[era].year) {
+    if(eyear == kEraInfo[era].year) {
         if(month == (kEraInfo[era].month-1)) {
             return kEraInfo[era].day;
         }

icu4c/source/i18n/japancal.h

@@ -192,17 +192,20 @@ protected:
      * Called by computeJulianDay.  Returns the default month (0-based) for the year,
      * taking year and era into account.  Will return the first month of the given era, if 
      * the current year is an ascension year.
+     * @param eyear the extended year
      * @internal
      */
-    virtual int32_t getDefaultMonthInYear();
+    virtual int32_t getDefaultMonthInYear(int32_t eyear);
 
     /***
      * Called by computeJulianDay.  Returns the default day (1-based) for the month,
      * taking currently-set year and era into account.  Will return the first day of the given
      * era, if the current month is an ascension year and month.
+     * @param eyear the extended year
+     * @param mon the month in the year
      * @internal
      */
-    virtual int32_t getDefaultDayInMonth(int32_t month);
+    virtual int32_t getDefaultDayInMonth(int32_t eyear, int32_t month);
 };
 
 U_NAMESPACE_END

icu4c/source/i18n/unicode/calendar.h

@@ -1715,18 +1715,20 @@ protected:
     /**
      * Called by computeJulianDay.  Returns the default month (0-based) for the year,
      * taking year and era into account.  Defaults to 0 for Gregorian, which doesn't care.
-     * @internal
+     * @param eyear The extended year
      * @internal
      */
-    virtual int32_t getDefaultMonthInYear() ;
+    virtual int32_t getDefaultMonthInYear(int32_t /*eyear*/) ;
 
 
     /**
      * Called by computeJulianDay.  Returns the default day (1-based) for the month,
      * taking currently-set year and era into account.  Defaults to 1 for Gregorian.
+     * @param eyear the extended year
+     * @param mon the month in the year
      * @internal
      */
-    virtual int32_t getDefaultDayInMonth(int32_t /*month*/);
+    virtual int32_t getDefaultDayInMonth(int32_t /*eyear*/, int32_t /*month*/);
 
     //-------------------------------------------------------------------------
     // Protected utility methods for use by subclasses.  These are very handy

icu4c/source/test/intltest/incaltst.cpp

@@ -670,8 +670,6 @@ void IntlCalendarTest::TestJapanese3860()
         }
     }
     
-#if 0
-    // this will NOT work - *all the time*. If it is the 1st of the month, for example it will get Jan 1 heisei 1  => jan 1 showa 64,  wrong era.
     {
         // Test simple parse/format with adopt
         UDate aDate = 0; 
@@ -701,7 +699,7 @@ void IntlCalendarTest::TestJapanese3860()
             int32_t gotYear = cal2->get(UCAL_YEAR, s2);
             int32_t gotEra = cal2->get(UCAL_ERA, s2);
             int32_t expectYear = 1;
-            int32_t expectEra = JapaneseCalendar::kCurrentEra;
+            int32_t expectEra = 235; //JapaneseCalendar::kCurrentEra;
             if((gotYear!=1) || (gotEra != expectEra)) {
                 errln(UnicodeString("parse "+samplestr+" of 'y' as Japanese Calendar, expected year ") + expectYear + 
                     UnicodeString(" and era ") + expectEra +", but got year " + gotYear + " and era " + gotEra + " (Gregorian:" + str +")");
@@ -711,7 +709,7 @@ void IntlCalendarTest::TestJapanese3860()
             delete fmt;
         }
     }    
-#endif
+
     delete cal2;
     delete cal;
     delete fmt2;