resolved fdo#63805 max day of month of the intended month

Since 6619955e Date::GetDaysInMonth()
operates on the normalized value that corresponds to the actual values
set at the Date instance, obtain and set number of days for the intended
month instead of using the rolled-over date.

Change-Id: Ia6b007675104f8e134b278f216c3bb48b72f061c

include/tools/date.hxx

@@ -138,6 +138,13 @@ public:
     TOOLS_DLLPUBLIC friend Date     operator -( const Date& rDate, long nDays );
     TOOLS_DLLPUBLIC friend long     operator -( const Date& rDate1, const Date& rDate2 );
 
+    /** Obtain number of days in a month of a year.
+
+        Internally sanitizes nMonth to values 1 <= nMonth <= 12, does not
+        normalize values.
+     */
+    static sal_uInt16 GetDaysInMonth( sal_uInt16 nMonth, sal_uInt16 nYear );
+
     /// Internally normalizes values.
     static long DateToDays( sal_uInt16 nDay, sal_uInt16 nMonth, sal_uInt16 nYear );
     /// Semantically identical to IsValidDate() member method.

sc/source/core/data/table4.cxx

@@ -1252,8 +1252,7 @@ void ScTable::IncDate(double& rVal, sal_uInt16& nDayOfMonth, double nStep, FillD
                 {
                     aDate.SetMonth((sal_uInt16) nMonth);
                     aDate.SetYear((sal_uInt16) nYear);
-                    if ( nDayOfMonth > 28 )
-                        aDate.SetDay( std::min( aDate.GetDaysInMonth(), nDayOfMonth ) );
+                    aDate.SetDay( std::min( Date::GetDaysInMonth( nMonth, nYear), nDayOfMonth ) );
                 }
             }
             break;

tools/source/datetime/tdate.cxx

@@ -44,7 +44,7 @@ inline sal_Bool ImpIsLeapYear( sal_uInt16 nYear )
 }
 
 // All callers must have sanitized or normalized month and year values!
-inline sal_uInt16 DaysInMonth( sal_uInt16 nMonth, sal_uInt16 nYear )
+inline sal_uInt16 ImplDaysInMonth( sal_uInt16 nMonth, sal_uInt16 nYear )
 {
     if ( nMonth != 2 )
         return aDaysInMonth[nMonth-1];
@@ -57,6 +57,17 @@ inline sal_uInt16 DaysInMonth( sal_uInt16 nMonth, sal_uInt16 nYear )
     }
 }
 
+// static
+sal_uInt16 Date::GetDaysInMonth( sal_uInt16 nMonth, sal_uInt16 nYear )
+{
+    SAL_WARN_IF( nMonth < 1 || 12 < nMonth, "tools", "Date::GetDaysInMonth - nMonth out of bounds " << nMonth);
+    if (nMonth < 1)
+        nMonth = 1;
+    else if (12 < nMonth)
+        nMonth = 12;
+    return ImplDaysInMonth( nMonth, nYear);
+}
+
 long Date::DateToDays( sal_uInt16 nDay, sal_uInt16 nMonth, sal_uInt16 nYear )
 {
     long nDays;
@@ -66,7 +77,7 @@ long Date::DateToDays( sal_uInt16 nDay, sal_uInt16 nMonth, sal_uInt16 nYear )
     nDays = ((sal_uIntPtr)nYear-1) * 365;
     nDays += ((nYear-1) / 4) - ((nYear-1) / 100) + ((nYear-1) / 400);
     for( sal_uInt16 i = 1; i < nMonth; i++ )
-        nDays += DaysInMonth(i,nYear);
+        nDays += ImplDaysInMonth(i,nYear);
     nDays += nDay;
     return nDays;
 }
@@ -105,9 +116,9 @@ static void DaysToDate( long nDays,
     while ( bCalc );
 
     rMonth = 1;
-    while ( (sal_uIntPtr)nTempDays > DaysInMonth( rMonth, rYear ) )
+    while ( (sal_uIntPtr)nTempDays > ImplDaysInMonth( rMonth, rYear ) )
     {
-        nTempDays -= DaysInMonth( rMonth, rYear );
+        nTempDays -= ImplDaysInMonth( rMonth, rYear );
         rMonth++;
     }
     rDay = (sal_uInt16)nTempDays;
@@ -179,7 +190,7 @@ sal_uInt16 Date::GetDayOfYear() const
     Normalize( nDay, nMonth, nYear);
 
     for( sal_uInt16 i = 1; i < nMonth; i++ )
-         nDay = nDay + ::DaysInMonth( i, nYear );   // += yields a warning on MSVC, so don't use it
+         nDay = nDay + ::ImplDaysInMonth( i, nYear );   // += yields a warning on MSVC, so don't use it
     return nDay;
 }
 
@@ -279,7 +290,7 @@ sal_uInt16 Date::GetDaysInMonth() const
     sal_uInt16 nYear  = GetYear();
     Normalize( nDay, nMonth, nYear);
 
-    return DaysInMonth( nMonth, nYear );
+    return ImplDaysInMonth( nMonth, nYear );
 }
 
 sal_Bool Date::IsLeapYear() const
@@ -296,7 +307,7 @@ sal_Bool Date::IsValidAndGregorian() const
 
     if ( !nMonth || (nMonth > 12) )
         return sal_False;
-    if ( !nDay || (nDay > DaysInMonth( nMonth, nYear )) )
+    if ( !nDay || (nDay > ImplDaysInMonth( nMonth, nYear )) )
         return sal_False;
     else if ( nYear <= 1582 )
     {
@@ -321,7 +332,7 @@ bool Date::IsValidDate( sal_uInt16 nDay, sal_uInt16 nMonth, sal_uInt16 nYear )
 {
     if ( !nMonth || (nMonth > 12) )
         return false;
-    if ( !nDay || (nDay > DaysInMonth( nMonth, nYear )) )
+    if ( !nDay || (nDay > ImplDaysInMonth( nMonth, nYear )) )
         return false;
     return true;
 }
@@ -371,7 +382,7 @@ bool Date::Normalize( sal_uInt16 & rDay, sal_uInt16 & rMonth, sal_uInt16 & rYear
         }
     }
     sal_uInt16 nDays;
-    while (rDay > (nDays = DaysInMonth( rMonth, rYear)))
+    while (rDay > (nDays = ImplDaysInMonth( rMonth, rYear)))
     {
         rDay -= nDays;
         if (rMonth < 12)