oleaut32: Return FALSE from SystemTimeToVariantTime if day > 31 or year is negative.

dlls/oleaut32/tests/vartest.c

@@ -1727,6 +1727,10 @@ static void test_SystemTimeToVariantTime(void)
   ST2DT(2,1,1980,0,0,0,0,TRUE,29222.0);
   ST2DT(0,1,1980,0,0,0,0,TRUE,29220.0);   /* Rolls back to 31 Dec 1899 */
   ST2DT(1,13,1980,0,0,0,0,FALSE,29587.0); /* Fails on invalid month */
+  ST2DT(32,1,1980,0,0,0,0,FALSE,0.0);     /* Fails on invalid day */
+  ST2DT(1,1,-1,0,0,0,0,FALSE,0.0);        /* Fails on invalid year */
+  ST2DT(1,1,10000,0,0,0,0,FALSE,0.0);     /* Fails on invalid year */
+  ST2DT(1,1,9999,0,0,0,0,TRUE,2958101.0); /* 9999 is last valid year */
   ST2DT(31,12,90,0,0,0,0,TRUE,33238.0);   /* 30 <= year < 100 is 1900+year */
   ST2DT(1,1,30,0,0,0,0,TRUE,10959.0);     /* 30 <= year < 100 is 1900+year */
   ST2DT(1,1,29,0,0,0,0,TRUE,47119.0);     /* 0 <= year < 30 is 2000+year */

dlls/oleaut32/variant.c

@@ -1312,6 +1312,10 @@ INT WINAPI SystemTimeToVariantTime(LPSYSTEMTIME lpSt, double *pDateOut)
 
   if (lpSt->wMonth > 12)
     return FALSE;
+  if (lpSt->wDay > 31)
+    return FALSE;
+  if ((short)lpSt->wYear < 0)
+    return FALSE;
 
   ud.st = *lpSt;
   return VarDateFromUdate(&ud, 0, pDateOut) == S_OK;