Bug #3073 mysql_stmt_close leaks memory if called after mysql_close

• Submitted: 5 Mar 2004 3:58
• Modified: 17 Mar 2004 8:30
• Reporter: Konstantin Osipov (OCA)
• Status: Closed
• Category: MySQL Server
• Severity: S2 (Serious)
• Version: 4.1
• OS: Any (all)
• Assigned to: Konstantin Osipov
• CPU Architecture: Any

[5 Mar 2004 3:58] Konstantin Osipov

Description:
In case mysql_stmt_close was called after mysql_close works this branch of mysql_stmt_close:

 if (!(mysql= stmt->mysql))
  {
    if (!skip_free)
      my_free((gptr) stmt, MYF(MY_WME));
    DBUG_RETURN(0);
  }

which just frees memory of the statement itself, and does not free stmt->mem_root and stmt->query.

How to repeat:
Write any testcase with mysql_close before mysql_stmt_close and run it under valgrind.

Suggested fix:
- remove skip_free from mysql_stmt_close.
- from mysql_close() just walk through all open statements and set stmt->mysql= 0
We don't need to call server to close statement entity on server side, because it's done automatically when connection is closed.
- rewrite branch with simple_command() in mysql_stmt_close() to work only if stmt->mysql is not zero.
- make sure all cleanups are done whether connection is alive or not.

[17 Mar 2004 8:30] Konstantin Osipov

Fixed in latest 4.1.2 tree: bk commit - 4.1 tree (konstantin:1.1781)