Bug #23280699: MYSQLD GOT SIGNAL 11 IN IS_NULL ON SELECT

               FROM I_S

Issue:
------
There is a difference in the field type created when the
following DDLs are used:

1) CREATE TABLE t0 AS SELECT NULL;
2) CREATE TABLE t0 AS SELECT GREATEST(NULL,NULL);

The first statement creates field of type Field_string and
the second one creates a field of type Field_null.

This creates a problem when the query mentioned in this bug
is used. Since the null_ptr is calculated differently for
Field_null.

Solution:
---------
When there is a function returning null in the select list
as mentioned above, the field should be of type
Field_string.

This was fixed in 5.6+ as part of Bug#14021323. This is a
backport to mysql-5.5.

An incorrect comment in innodb_bug54044.test has been
corrected in all versions.

1 files changed, 5 insertions, 6 deletions

diff --git a/mysql-test/suite/innodb/t/innodb_bug54044.test b/mysql-test/suite/innodb/t/innodb_bug54044.test
index 0bbd7da0065..cfc6f3c3f0a 100644
--- a/mysql-test/suite/innodb/t/innodb_bug54044.test
+++ b/mysql-test/suite/innodb/t/innodb_bug54044.test
@@ -10,10 +10,9 @@ CREATE TEMPORARY TABLE table_54044 ENGINE = INNODB
 SHOW CREATE TABLE table_54044;
 DROP TABLE table_54044;
 
-# These 'create table' operations should fail because of
-# using NULL datatype
+# This 'create table' should pass since it uses a Field_string of size 0.
 
---error ER_CANT_CREATE_TABLE
-CREATE TABLE tmp ENGINE = INNODB AS SELECT COALESCE(NULL, NULL, NULL);
---error ER_CANT_CREATE_TABLE
-CREATE TABLE tmp ENGINE = INNODB AS SELECT GREATEST(NULL, NULL);
+CREATE TABLE tmp ENGINE = INNODB
+ AS SELECT COALESCE(NULL, NULL, NULL), GREATEST(NULL, NULL), NULL;
+SHOW CREATE TABLE tmp;
+DROP TABLE tmp;