Bug#10446 Illegal mix of collations:

item_strfunc.h, item_strfunc.cc, item.cc:
  Try to convert a const item into destination 
  character set. If conversion happens without
  data loss, then cache the converted value
  and return it during val_str().
  Otherwise, if conversion loses data, return
  Illeral mix of collations error, as it happened
  previously.
ctype_recoding.result, ctype_recoding.test:
  Fixing tests accordingly.


sql/item.cc:
  Bug#10446 Illegal mix of collations
  Try to convert a const item into destination 
  character set. If conversion happens without
  data loss, then cache the converted value
  and return it during val_str().
  Otherwise, if conversion loses data, return
  Illeral mix of collations error, as it happened
  previously.
sql/item_strfunc.cc:
  Return cached value when it's possible.
mysql-test/t/ctype_recoding.test:
  Fixing tests accordingly.
mysql-test/r/ctype_recoding.result:
  Fixing tests accordingly.
This commit is contained in:
unknown 2005-11-21 17:26:31 +04:00
commit 72d19611d1
5 changed files with 53 additions and 15 deletions

View file

@ -614,10 +614,40 @@ public:
class Item_func_conv_charset :public Item_str_func
{
bool use_cached_value;
public:
bool safe;
CHARSET_INFO *conv_charset; // keep it public
Item_func_conv_charset(Item *a, CHARSET_INFO *cs) :Item_str_func(a)
{ conv_charset=cs; }
Item_func_conv_charset(Item *a, CHARSET_INFO *cs) :Item_str_func(a)
{ conv_charset= cs; use_cached_value= 0; safe= 0; }
Item_func_conv_charset(Item *a, CHARSET_INFO *cs, bool cache_if_const)
:Item_str_func(a)
{
DBUG_ASSERT(args[0]->fixed);
conv_charset= cs;
if (cache_if_const && args[0]->const_item())
{
uint errors= 0;
String tmp, *str= args[0]->val_str(&tmp);
if (!str || str_value.copy(str->ptr(), str->length(),
str->charset(), conv_charset, &errors))
null_value= 1;
use_cached_value= 1;
safe= (errors == 0);
}
else
{
use_cached_value= 0;
/*
Conversion from and to "binary" is safe.
Conversion to Unicode is safe.
Other kind of conversions are potentially lossy.
*/
safe= (args[0]->collation.collation == &my_charset_bin ||
cs == &my_charset_bin ||
(cs->state & MY_CS_UNICODE));
}
}
String *val_str(String *);
void fix_length_and_dec();
const char *func_name() const { return "convert"; }