Bug #95794 failed assertion when trying to create a column with timestamp value

• Submitted: 13 Jun 2019 15:56
• Modified: 20 Aug 2019 17:56
• Reporter: Martin Hansson
• Status: Closed
• Category: MySQL Server: DDL
• Severity: S2 (Serious)
• Version: 8.0.18
• OS: Any
• CPU Architecture: Any

[13 Jun 2019 15:56] Martin Hansson

Description:
Trying to use a standard SQL timestamp literal as the default column value causes the server to crash.

The following is printed:
mysqld: ../../sql/sql_parse.cc:5403: bool Alter_info::add_field(THD*, const LEX_STRING*, enum_field_types, const char*, const char*, uint, Item*, Item*, LEX_CSTRING*, const char*, List<String>*, const CHARSET_INFO*, bool, uint, Value_generator*, Value_generator*, const char*, Mysql::Nullable<unsigned int>, Sql_check_constraint_spec_list*, dd::Column::enum_hidden_type, bool): Assertion `dynamic_cast<Item_func_true *>(func) || dynamic_cast<Item_func_false *>(func)' failed.

How to repeat:
CREATE TABLE t1 ( a TIMESTAMP DEFAULT TIMESTAMP'2019-10-01 01:02:03' );
CREATE TABLE t1 ( a DATETIME DEFAULT TIMESTAMP'2019-10-01 01:02:03' );
CREATE TABLE t1 ( a INT DEFAULT TIMESTAMP'2019-10-01 01:02:03' );
...and so on...

[20 Aug 2019 17:56] Paul DuBois

Posted by developer:
 
Fixed in 8.0.19.

Incorrect checking of temporal literals for CREATE TABLE statements
could lead to a server exit.