Hi, Oleksandr!
On Oct 16, Oleksandr Byelkin wrote:
> revision-id: fcf2c5fff14 (mariadb-10.2.40-78-gfcf2c5fff14)
> parent(s): d5a15f04f4a
> author: Oleksandr Byelkin
> committer: Oleksandr Byelkin
> timestamp: 2021-10-01 14:46:22 +0200
> message:
>
> MDEV-26299: Some views force server (and mysqldump) to generate invalid SQL
> for their definitions
>
> Do not print illegal table field names for non-top-level SELECT list,
> they will not be refered in any case but create problem for parsing
> of printed result.
>
> diff --git a/sql/sql_select.cc b/sql/sql_select.cc
> index ff584e936b7..ebee9c85791 100644
> --- a/sql/sql_select.cc
> +++ b/sql/sql_select.cc
> @@ -25797,6 +25797,11 @@ void st_select_lex::print(THD *thd, String *str,
> enum_query_type query_type)
>
> //Item List
> bool first= 1;
> + /*
> + outer_select() can not be used here because it is for name resolution
> + and will return NULL at any end of name resolution chain (view/derived)
> + */
> + bool top_level= (get_master()->get_master() == 0);
> List_iterator_fast<Item> it(item_list);
> Item *item;
> while ((item= it++))
> @@ -25806,7 +25811,8 @@ void st_select_lex::print(THD *thd, String *str,
> enum_query_type query_type)
> else
> str->append(',');
>
> - if (is_subquery_function() && item->is_autogenerated_name)
> + if ((is_subquery_function() && item->is_autogenerated_name) ||
> + !item->name)
Where can item->name be NULL? I thought the either specified by the user
or autogenerated, but never NULL.
> {
> /*
> Do not print auto-generated aliases in subqueries. It has no purpose
> @@ -25815,7 +25821,26 @@ void st_select_lex::print(THD *thd, String *str,
> enum_query_type query_type)
> item->print(str, query_type);
> }
> else
> - item->print_item_w_name(str, query_type);
> + {
> + /*
> + Despite presence of item->name_length it is incorrect in many cases
> + till we start using LEX_STRING for the name.
> + */
> + size_t len= strlen(item->name);
> +
> + /*
> + Do not print illegal names (if it is not top level SELECT).
> + Top level view checked (and correct name are assigned),
> + other cases of top level SELECT are not important, because
> + it is not "table field".
> + */
> + if (top_level ||
> + !item->is_autogenerated_name ||
> + !check_table_name(item->name, len, TRUE))
why check_table_name() if it isn't a table? it's an incorrect check to
use for columns.
> + item->print_item_w_name(str, query_type);
> + else
> + item->print(str, query_type);
> + }
> }
>
> /*
>
Regards,
Sergei
VP of MariaDB Server Engineering
and secur...@mariadb.org
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