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| author | evgen@moonbone.local <> | 2007-05-17 23:09:45 +0400 |
|---|---|---|
| committer | evgen@moonbone.local <> | 2007-05-17 23:09:45 +0400 |
| commit | 0e3c4f67299950e23a3ba4b40defde2b0fc3b911 (patch) | |
| tree | 0329fe863c36b73face34cd7740fc6b177d4e36e /sql/item_cmpfunc.cc | |
| parent | 364014e4553c6dfb2bb33c575d6c1a6d4bb9fc4e (diff) | |
| download | mariadb-git-0e3c4f67299950e23a3ba4b40defde2b0fc3b911.tar.gz | |
Bug#28261: Wrong DATETIME comparison result when the GET_USER_VAR function
is involved.
The Arg_comparator::compare_datetime() comparator caches its arguments if
they are constants i.e. const_item() returns true. The
Item_func_get_user_var::const_item() returns true or false based on
the current query_id and the query_id where the variable was created.
Thus even if a query can change its value its const_item() still will return
true. All this leads to a wrong comparison result when an object of the
Item_func_get_user_var class is involved.
Now the Arg_comparator::can_compare_as_dates() and the
get_datetime_value() functions never cache result of the GET_USER_VAR()
function (the Item_func_get_user_var class).
Diffstat (limited to 'sql/item_cmpfunc.cc')
| -rw-r--r-- | sql/item_cmpfunc.cc | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc index 9a251312aca..3a79940b571 100644 --- a/sql/item_cmpfunc.cc +++ b/sql/item_cmpfunc.cc @@ -633,7 +633,13 @@ Arg_comparator::can_compare_as_dates(Item *a, Item *b, ulonglong *const_value) if (cmp_type != CMP_DATE_DFLT) { - if (cmp_type != CMP_DATE_WITH_DATE && str_arg->const_item()) + /* + Do not cache GET_USER_VAR() function as its const_item() may return TRUE + for the current thread but it still may change during the execution. + */ + if (cmp_type != CMP_DATE_WITH_DATE && str_arg->const_item() && + (str_arg->type() != Item::FUNC_ITEM || + ((Item_func*)str_arg)->functype() != Item_func::GUSERVAR_FUNC)) { THD *thd= current_thd; ulonglong value; @@ -780,7 +786,12 @@ get_datetime_value(THD *thd, Item ***item_arg, Item **cache_arg, MYSQL_TYPE_DATE ? MYSQL_TIMESTAMP_DATE : MYSQL_TIMESTAMP_DATETIME; value= get_date_from_str(thd, str, t_type, warn_item->name, &error); } - if (item->const_item() && cache_arg) + /* + Do not cache GET_USER_VAR() function as its const_item() may return TRUE + for the current thread but it still may change during the execution. + */ + if (item->const_item() && cache_arg && (item->type() != Item::FUNC_ITEM || + ((Item_func*)item)->functype() != Item_func::GUSERVAR_FUNC)) { Item_cache_int *cache= new Item_cache_int(); /* Mark the cache as non-const to prevent re-caching. */ |