Bug #14146 CHAR(...USING ...) and CONVERT(CHAR(...) USING...) produce different results

• Submitted: 19 Oct 2005 15:57
• Modified: 2 Dec 2005 20:41
• Reporter: Paul DuBois
• Status: Closed
• Category: MySQL Server
• Severity: S3 (Non-critical)
• Version: 5.0.15/5.0.16 BK source
• OS: Linux (Linux)
• Assigned to: Alexander Barkov
• CPU Architecture: Any

[19 Oct 2005 15:57] Paul DuBois

Description:
Recent changes to CHAR() (in 5.0.15) result in the following behavior
for CHAR(0xff USING utf8):

- Not strict mode: CHAR() returns 0xff, plus a warning (code 1300)
- Strict mode: CHAR() returns NULL, plus a warning (code 1300)

However, that behavior differs from CONVERT(CHAR(0xff) USING utf8)
in strict mode, though logically they should be equivalent.

mysql> set sql_mode='traditional';
Query OK, 0 rows affected (0.00 sec)

mysql> select char(0xff using utf8);
+-----------------------+
| char(0xff using utf8) |
+-----------------------+
| NULL                  |
+-----------------------+
1 row in set, 1 warning (0.00 sec)

mysql> select convert(char(0xff) using utf8);
+--------------------------------+
| convert(char(0xff) using utf8) |
+--------------------------------+
| ?                              |
+--------------------------------+
1 row in set (0.00 sec)

Shouldn't CONVERT() complain at least a little, and return NULL
when it cannot perform a legal conversion?

How to repeat:
See above.

[7 Nov 2005 8:39] Bugs System

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/internals/32032

[28 Nov 2005 14:38] Alexander Barkov

Reviewed by Ingo.
Pushed into 5.0.17

[28 Nov 2005 14:39] Alexander Barkov

Sorry, Reviewed by Jim actually.

[2 Dec 2005 20:41] Paul DuBois

Noted in 5.0.17 changelog.

[20 Dec 2006 10:21] Vladimir Shebordaev

See also bug #5929