MySQL Bugs: #4271: prepared explain complex select, second executes crashes the server

Bug #4271	prepared explain complex select, second executes crashes the server
Submitted:	24 Jun 2004 14:56	Modified:	25 Jun 2004 14:38
Reporter:	Matthias Leich	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server	Severity:	S3 (Non-critical)
Version:	4.1	OS:	Linux (linux)
Assigned to:	Oleksandr Byelkin	CPU Architecture:	Any

Description:
I have a very complex (non sense) select. If I perform the following sequence
  1. prepare stmt1 from <explain complex select> ;
  2. execute stmt1 ;
  3. execute stmt1 ;
the second execute crashes the mysqld server.

The attached file master.err contains the error log of the server.

I do NOT claim that the my select statements make sense in the real world
and I do NOT think that this bug is very important. But may be that
somebody can catch the same bug with a simple, non artificial select. 

My environment: Intel PC with Linux(SuSE 9.0),
   MySQL 4.1 source distrib.(last bk pull 2004-06-22)

How to repeat:
Please use my test file, copy it to mysql-test/t
  ./mysql-test-run ml_err7

The structure of ml_err7:
-------------------------
There are 14 versions of my bad explain select. The original and
most complex version is at the end of the file. The most simple
version is at the beginning of the file. That means the complexity
increases from the beginning to the end of the test case file. 
I hope this accelerates the bug fixing process.

test case

Attachment: ml_err7.test (application/octet-stream, text), 7.08 KiB.

server log

Attachment: master.err (application/octet-stream, text), 3.85 KiB.

ChangeSet 
  1.1989 04/06/25 11:37:43 bell@sanja.is.com.ua +4 -0 
  fixed EXPLAIN behaviour with prepared statements (BUG#4271)

Thank you for bugreport! Patch is pushed to source repository now.