MDEV-3942 FROM_DAYS(<timestamp column>) returns different result in MariaDB...

MDEV-3942 FROM_DAYS(<timestamp column>) returns different result in MariaDB comparing to MySQL: NULL vs 0000-00-00

fixed a regression, introduced while fixing MDEV-456

mysql-test/r/datetime_456.result

@@ -4,5 +4,5 @@ insert t1 values (addtime('9999-12-31 23:59:59', '00:00:01')),
 select * from t1;
 d
 NULL
-NULL
+0000-00-00 00:00:00
 drop table t1;

mysql-test/r/func_time.result

@@ -1453,7 +1453,7 @@ MAKEDATE(11111111,1)
 NULL
 SELECT WEEK(DATE_ADD(FROM_DAYS(1),INTERVAL 1 MONTH), 1);
 WEEK(DATE_ADD(FROM_DAYS(1),INTERVAL 1 MONTH), 1)
-NULL
+0
 #
 # Bug#12584302 AFTER FIX FOR #12403504: ASSERTION FAILED: DELSUM+(INT) Y/4-TEMP > 0,
 #

sql/item_timefunc.cc

 /*
    Copyright (c) 2000, 2012, Oracle and/or its affiliates.
+   Copyright (c) 2010, 2013, Monty Program Ab
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -1386,13 +1387,10 @@ bool Item_func_from_days::get_date(MYSQL_TIME *ltime, uint fuzzy_date)
 
   if (get_date_from_daynr((long) value, &ltime->year, &ltime->month,
                           &ltime->day))
-    return (null_value= 1);
-
-  if ((fuzzy_date & TIME_NO_ZERO_DATE) && ltime->year == 0)
-    return (null_value= 1);
+    return 0;
 
   ltime->time_type= MYSQL_TIMESTAMP_DATE;
-  return (null_value= 0);
+  return 0;
 }
 
 

sql/time.cc

 /*
    Copyright (c) 2000-2007 MySQL AB, 2009 Sun Microsystems, Inc.
-   Copyright (c) 2009-2011 Monty Program Ab
+   Copyright (c) 2009-2013 Monty Program Ab
    Use is subject to license terms.
 
    This program is free software; you can redistribute it and/or modify
@@ -153,7 +153,7 @@ bool get_date_from_daynr(long daynr,uint *ret_year,uint *ret_month,
   uchar *month_pos;
   DBUG_ENTER("get_date_from_daynr");
 
-  if (daynr < 365 || daynr > MAX_DAY_NUMBER)
+  if (daynr < 366 || daynr > MAX_DAY_NUMBER)
     DBUG_RETURN(1);
 
   year= (uint) (daynr*100 / 36525L);