MySQL Bugs: #29353: inserting a negative value to a csv table leads to the table corruption

Bug #29353	inserting a negative value to a csv table leads to the table corruption
Submitted:	26 Jun 2007 7:11	Modified:	10 Jul 2007 22:41
Reporter:	Ramil Kalimullin	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: CSV	Severity:	S1 (Critical)
Version:	5.1 source	OS:	Any
Assigned to:	Ramil Kalimullin	CPU Architecture:	Any

Description:
mysql> create table t1(a int)engine=csv;
Query OK, 0 rows affected (0.01 sec)

mysql> insert into t1 values(-1);
Query OK, 1 row affected (0.00 sec)

mysql> select * from t1;
ERROR 1194 (HY000): Table 't1' is marked as crashed and should be repaired

mysql> check table t1;
+---------+-------+----------+----------+
| Table   | Op    | Msg_type | Msg_text |
+---------+-------+----------+----------+
| test.t1 | check | error    | Corrupt  | 
+---------+-------+----------+----------+
1 row in set (0.00 sec)

How to repeat:
create table t1(a int)engine=csv;
insert into t1 values(-1);
select * from t1; // Table 't1' is marked as crashed

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/29588

ChangeSet@1.2510, 2007-06-26 16:26:32+05:00, ramil@mysql.com +3 -0
  Fix for bug #29353: inserting a negative value to a csv table leads to the table corruption
  
  Problem: we believe a number cannot start with '-' ['+'] sign reading rows.
  
  Fix: properly handle starting '-' and '+' signs that may occur before numbers.

The patch looks ok.

I also suggest to simplify the code starting from

    else if (my_isdigit(system_charset_info,
                        file_buff->get_value(curr_offset)))
    {

to scan everything until comma or until end-of-line,
without checking digits or dots.
It will allow to open csv files with numbers written
in full scientific notation, e.g.:

.10 
1e+5

and so on.

Field->store() will accept all correct formats,
or will return error for unknown formats.

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/29692

ChangeSet@1.2522, 2007-06-27 16:20:00+05:00, ramil@mysql.com +3 -0
  Fix for bug #29353: inserting a negative value to a csv table leads to the table corruption
  
  Problem: we believe a number cannot start with '-' ['+'] sign reading rows.
  
  Fix: let field->store() check given values.

ok to push

Ok to push.

http://lists.mysql.com/commits/30165

ChangeSet@1.2534, 2007-07-03 17:17:58+05:00, ramil@mysql.com +8 -0
  Complementary fix for bug #29353: inserting a negative value to a csv table 
  leads to the table corruption
  
  New Field::store() method implemented to explicitly set thd->count_cuted_fields
  before value storing, instead of (incorrectly) setting it in the CSV storage engine.
  Thread row counter now properly incremented during check and repair in the CSV engine.

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/30165

ChangeSet@1.2534, 2007-07-03 17:17:58+05:00, ramil@mysql.com +8 -0
  Complementary fix for bug #29353: inserting a negative value to a csv table 
  leads to the table corruption
  
  New Field::store() method implemented to explicitly set thd->count_cuted_fields
  before value storing, instead of (incorrectly) setting it in the CSV storage engine.
  Thread row counter now properly incremented during check and repair in the CSV engine.

Pushed into 5.1.21-beta

Noted in 5.1.21 changelog.

Inserting a negative number into a CSV table could corrupt it.