diff options
Diffstat (limited to 'sql/item_buff.cc')
| -rw-r--r-- | sql/item_buff.cc | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/sql/item_buff.cc b/sql/item_buff.cc index 0ac4edb3656..b15083f54a2 100644 --- a/sql/item_buff.cc +++ b/sql/item_buff.cc @@ -27,11 +27,15 @@ Create right type of Cached_item for an item. */ -Cached_item *new_Cached_item(THD *thd, Item *item) +Cached_item *new_Cached_item(THD *thd, Item *item, bool pass_through_ref) { - if (item->real_item()->type() == Item::FIELD_ITEM && + if (pass_through_ref && item->real_item()->type() == Item::FIELD_ITEM && !(((Item_field *) (item->real_item()))->field->flags & BLOB_FLAG)) - return new Cached_item_field((Item_field *) (item->real_item())); + { + Item_field *real_item= (Item_field *) item->real_item(); + Field *cached_field= real_item->field; + return new Cached_item_field(cached_field); + } switch (item->result_type()) { case STRING_RESULT: return new Cached_item_str(thd, (Item_field *) item); @@ -117,14 +121,20 @@ bool Cached_item_int::cmp(void) bool Cached_item_field::cmp(void) { - bool tmp= field->cmp(buff) != 0; // This is not a blob! - if (tmp) - field->get_image(buff,length,field->charset()); + bool tmp= FALSE; // Value is identical + /* Note that field can't be a blob here ! */ if (null_value != field->is_null()) { null_value= !null_value; - tmp=TRUE; + tmp= TRUE; // Value has changed } + + /* + If value is not null and value changed (from null to not null or + becasue of value change), then copy the new value to buffer. + */ + if (! null_value && (tmp || (tmp= (field->cmp(buff) != 0)))) + field->get_image(buff,length,field->charset()); return tmp; } |