From ac460e584d9706e02ce3dcb86bd994276672b267 Mon Sep 17 00:00:00 2001 From: Sreeharsha Ramanavarapu Date: Fri, 22 Jul 2016 07:33:43 +0530 Subject: [PATCH] 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. --- mysql-test/suite/innodb/r/innodb_bug54044.result | 14 ++++++++++---- mysql-test/suite/innodb/t/innodb_bug54044.test | 11 +++++------ sql/item.cc | 5 +---- 3 files changed, 16 insertions(+), 14 deletions(-) diff --git a/mysql-test/suite/innodb/r/innodb_bug54044.result b/mysql-test/suite/innodb/r/innodb_bug54044.result index 350c500cb9b..29b0127f20b 100644 --- a/mysql-test/suite/innodb/r/innodb_bug54044.result +++ b/mysql-test/suite/innodb/r/innodb_bug54044.result @@ -6,7 +6,13 @@ table_54044 CREATE TEMPORARY TABLE `table_54044` ( `IF(NULL IS NOT NULL, NULL, NULL)` binary(0) DEFAULT NULL ) ENGINE=InnoDB DEFAULT CHARSET=latin1 DROP TABLE table_54044; -CREATE TABLE tmp ENGINE = INNODB AS SELECT COALESCE(NULL, NULL, NULL); -ERROR HY000: Can't create table 'test.tmp' (errno: -1) -CREATE TABLE tmp ENGINE = INNODB AS SELECT GREATEST(NULL, NULL); -ERROR HY000: Can't create table 'test.tmp' (errno: -1) +CREATE TABLE tmp ENGINE = INNODB +AS SELECT COALESCE(NULL, NULL, NULL), GREATEST(NULL, NULL), NULL; +SHOW CREATE TABLE tmp; +Table Create Table +tmp CREATE TABLE `tmp` ( + `COALESCE(NULL, NULL, NULL)` binary(0) DEFAULT NULL, + `GREATEST(NULL, NULL)` binary(0) DEFAULT NULL, + `NULL` binary(0) DEFAULT NULL +) ENGINE=InnoDB DEFAULT CHARSET=latin1 +DROP TABLE tmp; 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; diff --git a/sql/item.cc b/sql/item.cc index 1541314ec97..34157c33cf4 100644 --- a/sql/item.cc +++ b/sql/item.cc @@ -5360,10 +5360,6 @@ Field *Item::tmp_table_field_from_field_type(TABLE *table, bool fixed_length) field= new Field_double((uchar*) 0, max_length, null_ptr, 0, Field::NONE, name, decimals, 0, unsigned_flag); break; - case MYSQL_TYPE_NULL: - field= new Field_null((uchar*) 0, max_length, Field::NONE, - name, &my_charset_bin); - break; case MYSQL_TYPE_INT24: field= new Field_medium((uchar*) 0, max_length, null_ptr, 0, Field::NONE, name, 0, unsigned_flag); @@ -5394,6 +5390,7 @@ Field *Item::tmp_table_field_from_field_type(TABLE *table, bool fixed_length) DBUG_ASSERT(0); /* If something goes awfully wrong, it's better to get a string than die */ case MYSQL_TYPE_STRING: + case MYSQL_TYPE_NULL: if (fixed_length && max_length < CONVERT_IF_BIGGER_TO_BLOB) { field= new Field_string(max_length, maybe_null, name,