BUG#13354387 - CRASH IN IN MY_DECIMAL::OPERATOR FOR VIEW AND FUNCTION UNIX_TIME

Fixing the 5.5 part (the 5.6 part will go in a separate commit soon).

Problem:
  Item_direct_ref::get_date() incorrectly calculated its "null_value",
  which made UNIX_TIMESTAMP(view_column) incorrectly return NULL
  for a NOT NULL view_column.

Fix:
  Make Item_direct_ref::get_date() calculate null_value
  in the similar way with the other methods 
  (val_real,val_str,val_int,val_decimal):
  copy null_value from the referenced Item.

modified:
  mysql-test/r/func_time.result
  mysql-test/t/func_time.test
  sql/item.cc

mysql-test/r/func_time.result

@@ -1433,6 +1433,21 @@ NULL	1	NULL
 SET storage_engine=NULL;
 ERROR 42000: Variable 'storage_engine' can't be set to the value of 'NULL'
 #
+# BUG#13354387 - CRASH IN IN MY_DECIMAL::OPERATOR FOR VIEW AND FUNCTION UNIX_TIMESTAMP 
+# Part1 (5.5)
+SET time_zone='+03:00';
+CREATE TABLE t1 (a DATETIME NOT NULL);
+INSERT INTO t1 VALUES ('2009-09-20 07:32:39.06');
+INSERT INTO t1 VALUES ('0000-00-00 00:00:00.00');
+CREATE VIEW v1 AS SELECT * FROM t1;
+SELECT CAST(UNIX_TIMESTAMP(a) AS DECIMAL(25,3)) AS c1 FROM v1 ORDER BY 1;
+c1
+0.000
+1253421159.000
+DROP VIEW v1;
+DROP TABLE t1;
+SET time_zone=DEFAULT;
+#
 # Bug #59686 crash in String::copy() with time data type
 #
 SELECT min(timestampadd(month, 1>'', from_days('%Z')));

mysql-test/t/func_time.test

@@ -940,6 +940,21 @@ SELECT MONTHNAME(0), MONTHNAME(0) IS NULL, MONTHNAME(0) + 1;
 --error ER_WRONG_VALUE_FOR_VAR
 SET storage_engine=NULL;
 
+
+--echo #
+--echo # BUG#13354387 - CRASH IN IN MY_DECIMAL::OPERATOR FOR VIEW AND FUNCTION UNIX_TIMESTAMP 
+--echo # Part1 (5.5)
+SET time_zone='+03:00';
+CREATE TABLE t1 (a DATETIME NOT NULL);
+INSERT INTO t1 VALUES ('2009-09-20 07:32:39.06');
+INSERT INTO t1 VALUES ('0000-00-00 00:00:00.00');
+CREATE VIEW v1 AS SELECT * FROM t1;
+SELECT CAST(UNIX_TIMESTAMP(a) AS DECIMAL(25,3)) AS c1 FROM v1 ORDER BY 1; 
+DROP VIEW v1;
+DROP TABLE t1;
+SET time_zone=DEFAULT;
+
+
 --echo #
 --echo # Bug #59686 crash in String::copy() with time data type
 --echo #

sql/item.cc

@@ -6812,7 +6812,9 @@ bool Item_direct_ref::is_null()
 
 bool Item_direct_ref::get_date(MYSQL_TIME *ltime,uint fuzzydate)
 {
-  return (null_value=(*ref)->get_date(ltime,fuzzydate));
+  bool tmp= (*ref)->get_date(ltime, fuzzydate);
+  null_value= (*ref)->null_value;
+  return tmp;
 }