Bug #42321 --change_user with default args works different in embedded and standalone mode

• Submitted: 24 Jan 2009 14:05
• Modified: 9 Jan 2015 16:01
• Reporter: Gleb Shchepa
• Status: Can't repeat
• Category: Tools: MTR / mysql-test-run
• Severity: S3 (Non-critical)
• Version: 5.0, 5.1, 6.0 bzr
• OS: Any
• Assigned to: Bjørn Munch
• CPU Architecture: Any
• Tags: change_user, embedded, mysqltest, regression

[24 Jan 2009 14:05] Gleb Shchepa

Description:
The mysqltest client executes the "change_user" command without database name parameter differently under standalone and embedded server mode:

a) for standalone server mode it uses _current_ database as default database,
b) for embedded server it uses _no_ database as default database.

How to repeat:
Standard test file:

--disable_warnings
DROP TABLE IF EXISTS t1;
--enable_warnings
CREATE TABLE t1 (i INT);
--change_user
SELECT * FROM t1;
DROP TABLE t1;

Standalone server mode: no errors.
Embedded server mode:

mysqltest: At line 6: query 'SELECT * FROM t1' failed: 1046: No database selected

Suggested fix:
For a standalone mode a client program calls CLI_MYSQL_REAL_CONNECT() that set MYSQL::db field to opening database name. Then mysqltest uses that field value as default database name for --change_user command etc. However, a client doesn't call that function in embedded mode, and its MYSQL::db field is always set to NULL.

Probably it may be a robust solution to move an assignment of the current database name to MYSQL::db field from the CLI_MYSQL_REAL_CONNECT function to all kinds of mysql_real_connect function.

[25 Jan 2009 17:14] Sveta Smirnova

Thank you for the report.

Verified as described. With version 4.1 bug is not repeatable.