From: Sergey Vojtovich
Date: February 4 2011 7:00am
Subject: Re: bzr commit into mysql-5.5 branch (alexander.barkov:3294)
List-Archive: http://lists.mysql.com/commits/130356
Message-Id: <20110204070014.GA17437@june>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii

Hi Alexander,

still, there is one question...

On Tue, Feb 01, 2011 at 03:36:16PM -0000, Alexander Barkov wrote:
> #At file:///home/bar/mysql-bzr/mysql-5.5.b58036/ based on revid:ole.john.aske@stripped
> 
>  3294 Alexander Barkov	2011-02-01
BUG#.... line is missing.

>       Problem: ucs2 was correctly disallowed in "SET NAMES" only,
>       while mysql_real_connect() and mysql_change_user() still allowed
>       to use ucs2, which made server crash.
...skip...

> === modified file 'sql/sql_acl.cc'
> --- a/sql/sql_acl.cc	2011-01-14 15:48:11 +0000
> +++ b/sql/sql_acl.cc	2011-02-01 15:30:06 +0000
> @@ -7799,7 +7799,8 @@ public:
>    Thd_charset_adapter(THD *thd_arg) : thd (thd_arg) {} 
>    bool init_client_charset(uint cs_number)
>    {
> -    thd_init_client_charset(thd, cs_number);
> +    if (thd_init_client_charset(thd, cs_number))
> +      return true;
>      thd->update_charset();
>      return thd->is_error();
>    }
> @@ -8236,6 +8237,18 @@ static bool parse_com_change_user_packet
>    uint dummy_errors;
>  
>    DBUG_ENTER ("parse_com_change_user_packet");
> +
> +  /*
> +    The caller expects that this function allocates user_name using
> +    my_strndup() and calls my_free(user_name) later in some cases.
> +
> +    Let's set user_name to NULL here, to avoid my_free() on uninitialized
> +    memory for those cases when we return from here *before* user_name is
> +    actually allocated. This happens on errors: packet error, bad charset.
> +  */
> +  mpvio->auth_info.user_name= NULL;
> +  mpvio->auth_info.user_name_length= 0;
> +
>    if (passwd >= end)
>    {
>      my_message(ER_UNKNOWN_COM_ERROR, ER(ER_UNKNOWN_COM_ERROR), MYF(0));
> 
When does the caller set auth_info.user_name to not NULL and when does the
caller free it?

Regards,
Sergey
-- 
Sergey Vojtovich <svoj@stripped>
MySQL AB, Software Engineer
Izhevsk, Russia, www.mysql.com