vtime2timeval: check validity of month

ChangeLog

@@ -3,6 +3,10 @@
 	* Version 1.6.0 released
 	* using CGRIBEX library version 1.6.0
 
+2013-03-08  Uwe Schulzweida  <Uwe.Schulzweida@zmaw.de>
+
+	* vtime2timeval: check validity of month
+
 2013-03-07  Uwe Schulzweida  <Uwe.Schulzweida@zmaw.de>
 
 	* cdfDefGrid: bug fix for generic grids with nx or ny > 0

src/taxis.c

@@ -1015,8 +1015,6 @@ double vtime2timeval(int vdate, int vtime, taxis_t *taxis)
     {
       int nmonth, dpm;
 
-      dpm = days_per_month(calendar, year, month);
-
       value = (year-ryear)*12 - rmonth + month;
 
       nmonth = (int) value;
@@ -1025,6 +1023,8 @@ double vtime2timeval(int vdate, int vtime, taxis_t *taxis)
       while ( month > 12 ) { month -= 12; year++; }
       while ( month <  1 ) { month += 12; year--; }
 
+      dpm = days_per_month(calendar, year, month);
+
       encode_caldaysec(calendar, year, month, day, hour, minute, second, &julday2, &secofday2);
 
       julday_sub(julday1, secofday1, julday2, secofday2, &days, &secs);