diff options
Diffstat (limited to 'sql')
| -rw-r--r-- | sql/item.cc | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/sql/item.cc b/sql/item.cc index ec33bf1ddc7..11a5039ca19 100644 --- a/sql/item.cc +++ b/sql/item.cc @@ -4075,7 +4075,9 @@ bool Item_field::set_no_const_sub(byte *arg) DESCRIPTION The function returns a pointer to an item that is taken from the very beginning of the item_equal list which the Item_field - object refers to (belongs to). + object refers to (belongs to) unless item_equal contains a constant + item. In this case the function returns this constant item, + (if the substitution does not require conversion). If the Item_field object does not refer any Item_equal object 'this' is returned @@ -4084,7 +4086,8 @@ bool Item_field::set_no_const_sub(byte *arg) of the thransformer method. RETURN VALUES - pointer to a replacement Item_field if there is a better equal item; + pointer to a replacement Item_field if there is a better equal item or + a pointer to a constant equal item; this - otherwise. */ @@ -4092,6 +4095,14 @@ Item *Item_field::replace_equal_field(byte *arg) { if (item_equal) { + Item *const_item= item_equal->get_const(); + if (const_item) + { + if (cmp_context != (Item_result)-1 && + const_item->cmp_context != cmp_context) + return this; + return const_item; + } Item_field *subst= item_equal->get_first(); if (subst && !field->eq(subst->field)) return subst; |