Re: bk commit into 5.0 tree (bar:1.2518) BUG#28875

[Sergei Golubchik]

Hi!

On Aug 01, bar@stripped wrote:
> ChangeSet@stripped, 2007-08-01 16:25:51+05:00, bar@stripped +19 -0
>   Bug#28875 Conversion between ASCII and LATIN1 charsets does not function
>   (Regression, caused by a patch for the bug 22646).
>   Problem: when result type of date_format() was changed from
>   binary string to character string, mixing date_format()
>   with a ascii column in CONCAT() stopped to work.
>   Fix:
>   - adding "repertoire" flag into DTCollation class,
>   to mark items which can return only pure ASCII strings.
>   - allow character set conversion from pure ASCII to other character sets.

Ok to push
with a couple of changes.
 
> --- 1.223/sql/sql_lex.cc	2007-05-26 03:17:18 +05:00
> +++ 1.224/sql/sql_lex.cc	2007-08-01 16:25:45 +05:00
> @@ -305,16 +305,18 @@ static LEX_STRING get_quoted_token(Lex_i
>    Fix sometimes to do only one scan of the string
>  */
>  
> -static char *get_text(Lex_input_stream *lip)
> +static char *get_text(Lex_input_stream *lip, uchar *bitmask)

Please, consider moving bitmap to Lex_input_stream.
Something like tok_bitmap.

>  {
>    reg1 uchar c,sep;
>    uint found_escape= 0;
>    CHARSET_INFO *cs= lip->m_thd->charset();
>  
> +  *bitmask= 0;
>    sep= yyGetLast();                     // String should end with this
>    while (lip->ptr != lip->end_of_query)
>    {
>      c= yyGet();
> +    *bitmask|= c;
>  #ifdef USE_MB
>      {

Second comment: Add to String::copy a check to avoid charset conversion
if from_cs is ascii.

Because now you have a function that tells "X charset is a superset of Y
charset", and then you call String::copy to convert. But "utf8 is a
superset of latin1" is different from "latin1 is a superset of ascii" -
in the first case one needs to convert the string, in the second memcpy
is enough.

Regards / Mit vielen Grüssen,
Sergei

-- 
   __  ___     ___ ____  __
  /  |/  /_ __/ __/ __ \/ /   Sergei Golubchik <serg@stripped>
 / /|_/ / // /\ \/ /_/ / /__  Principal Software Developer
/_/  /_/\_, /___/\___\_\___/  MySQL GmbH, Radlkoferstr. 2, D-81373 München
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