MySQL Bugs: #54103: Catalog functions return incorrect data if SYSTEM_CHARSET

Bug #54103	Catalog functions return incorrect data if SYSTEM_CHARSET_MBMAXLEN!=3(4 in C/C)
Submitted:	31 May 2010 12:48	Modified:	31 May 2010 12:51
Reporter:	Lawrenty Novitsky	Email Updates:
Status:	Verified	Impact on me:	None
Category:	Connector / ODBC	Severity:	S2 (Serious)
Version:		OS:	Any
Assigned to:	Assigned Account	CPU Architecture:	Any

Description:
Octet length and display size may be returned incorrectly in many catalog functions(where/when i_s is not used)
That happens because c/odbc uses SYSTEM_CHARSET_MBMAXLEN macro and utf8 charset in constructed fields, but mbmaxlen for the utf8(33) charset is 3. So SYSTEM_CHARSET_MBMAXLEN defined as 4 in the c/c messes columns octet and character sizes.

How to repeat:
Build using c/c and run my_catalog tests

Suggested fix:
Not to use SYSTEM_CHARSET_MBMAXLEN or its dependents in MYODBC_FIELD_NAME and MYODBC_FIELD_STRING macros, but calculated mbmaxlen for UTF8_CHARSET_NUMBER. In this case if c/odbc need to return data(or maybe more correct to say that if server returns data) using different charset(some 4 byte utf), the only thing needed to be change to take care of that problem in catalog functions would be the charset number.

Or we could fix those macros for the c/c version of headers only.

Lawrin, could it be that Bug#54088 is side-effect of this one?

Tonci, Lawrin,

Lawrin for info I did create bug report #54088 and my first impression is that Tonci could be right in his feeling that the two bugs could be related.

Perhaps (I do not know), it is posible for me to verify if the tow bugs are related. Does one of you perhaps have a sugestion how to test this !?

Please read what I did already test.

Sincerely,

Louis

Tonci, Louis
My opinion they are not related. This bug is caused by change in the client library, and not in the server.