maria-developers team mailing list archive

[Sergei Golubchik <serg@xxxxxxxxxxx>]

Hi, Sachin!

On Aug 20, Sachin Setiya wrote:
> revision-id: c776ed4d6ec (mariadb-10.4.5-153-gc776ed4d6ec)
> parent(s): 4ca016237f1
> author: Sachin <sachin.setiya@xxxxxxxxxxx>
> committer: Sachin <sachin.setiya@xxxxxxxxxxx>
> timestamp: 2019-07-30 03:42:21 +0530
> message:
> 
> MDEV-19848 Server crashes in check_vcol_forward_refs upon INSERT DELAYED into table with long blob key
> 
> There are 2 issues
> 
>   1st:- in make_new_field when we & into new field flag we forget
>   LONG_UNIQUE_HASH_FIELD Flag.
> 
>   2nd:- We are calling parse_vcol_defs on keyinfo , but they are not in right
>   form. We should call setup_keyinfo_hash_all before calling parse_vcol_defs

This looks quite suspicious.

Ideally, Delayed_insert::get_local_table() should just create a copy of
the table, but not modify the original table. In your case it constantly
modifies KEY's of the original table.  It's kind of dirty.

As for the real bug, see what parse_vcol_defs() is doing for long unique
fields. In particular, it sets

  keypart->field->vcol_info=
    table->field[keypart->field->field_index]->vcol_info;

but the keypart here is in the original Delayed_insert::table,
while field and vcol_info is in a copy (created in
Delayed_insert::get_local_table). This seems to be just wrong.

I'd really prefer Delayed_insert::get_local_table to not change anything
in the Delayed_insert::table.

Regards,
Sergei
VP of MariaDB Server Engineering
and security@xxxxxxxxxxx