Merge mysql.com:/home/jimw/my/mysql-4.1-clean

into  mysql.com:/home/jimw/my/mysql-5.0-clean

mysql-test/r/func_math.result

@@ -170,6 +170,12 @@ insert into t1 values (1);
 select rand(i) from t1;
 ERROR HY000: Incorrect arguments to RAND
 drop table t1;
+create table t1 (a varchar(90), ts datetime not null, index (a)) engine=innodb default charset=utf8;
+insert into t1 values ('http://www.foo.com/', now());
+select a from t1 where a='http://www.foo.com/' order by abs(timediff(ts, 0));
+a
+http://www.foo.com/
+drop table t1;
 set sql_mode='traditional';
 select ln(-1);
 ln(-1)

mysql-test/t/func_math.test

@@ -116,6 +116,16 @@ insert into t1 values (1);
 select rand(i) from t1;
 drop table t1;
 
+#
+# Bug #14009: use of abs() on null value causes problems with filesort
+#
+# InnoDB is required to reproduce the fault, but it is okay if we default to
+# MyISAM when testing.
+create table t1 (a varchar(90), ts datetime not null, index (a)) engine=innodb default charset=utf8;
+insert into t1 values ('http://www.foo.com/', now());
+select a from t1 where a='http://www.foo.com/' order by abs(timediff(ts, 0));
+drop table t1;
+
 # End of 4.1 tests
 
 #

sql/item_func.cc

@@ -636,6 +636,7 @@ void Item_func_num1::fix_num_length_and_dec()
 {
   decimals= args[0]->decimals;
   max_length= args[0]->max_length;
+  maybe_null= 1;
 }