MySQL Bugs: #114: Bug in LOCK TABLE followed by DROP TABLE

Bug #114	Bug in LOCK TABLE followed by DROP TABLE
Submitted:	2 Mar 2003 9:30	Modified:	3 Mar 2003 11:05
Reporter:	Peter Zaitsev (Basic Quality Contributor)	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server	Severity:	S3 (Non-critical)
Version:	3.23 and 4.0	OS:
Assigned to:	Michael Widenius	CPU Architecture:	Any

Description:
The folowing sequence of commands leads to deadlock,
one is connections can be killed in order to break deadlock which makes it less serious: 

How to repeat:
Notice order of tables is important to reproduce deadlock.

connection1;
create table x(i int);
create table y(i int);
lock table x write, y write
connection2;
insert x select * from y;
connection1;
drop table y;
<deadlock>

A bug is fixed in 3.23.56, and a fix will be merged in 4.0.12

A patch is too large for this database.

Thank you for your bug report. This issue has been fixed in the latest
development tree for that product. You can find more information about
accessing our development trees at 
    http://www.mysql.com/doc/en/Installing_source_tree.html

This bug was not fixed by the LOCK TABLE patch we added to 3.23.
To fix this problem we had to introduce new ways to abort locks that we don't want to introduce in the stable 3.23 branch.
In other words, this bug is fixed in the 4.0 tree but will not be fixed in 3.23. I will update the manual to reflect this.