maria-developers team mailing list archive

[Alexander Barkov <bar@xxxxxxxxxxx>]

Hi Sergei,


Here's a new patch:

https://github.com/MariaDB/server/commit/0478f474020466c16bfcbc9c7d0ed582a40e4fb8


Please also see comments below. Thanks.


On 1/17/22 8:09 PM, Sergei Golubchik wrote:
> Hi, Alexander!


> > We cannot have auto-generated nested CONVERT().
> >
> > The new code just reproduces the old behavior:
> > Item_func_conv_charset::is_json_type() traversed
> > through all Item_func_conv_charset's recursively.
> >
> > As the comment says, this is probably not correct.
> > Let's fix it under terms of a separate MDEV.
> > I can file an MDEV about this.
>
> please, do


MDEV-27533 The result of `CONVERT(json USING ...)` is erroneously 
treated as JSON


> > > > diff --git a/sql/sql_type.cc b/sql/sql_type.cc
> > class Type_handler_pair
> > {
> >     const Type_handler *m_a;
> >     const Type_handler *m_b;
> > ...
> > };
>
> why did you do it this way? You create an object. Then in the loop you
> create a new object, copying the old one. Then you conditionally assign
> m_a->type_handler_base(). Then you diff then to see if any condition
> from the previous step has succeeded.
>
> Why not, like
>
>    class Type_handler_pair {
>      bool up() {
>        bool r=false;
>        n_a=m_a->type_handler_base();
>        n_b=m_b->type_handler_base();
>        if (n_a) { m_a=n_a; r=true; }
>        if (n_b) { m_a=n_b; r=true; }
>        return r;
>      }
>
> and later
>
>     do {
>        ...
>     } while (tp.up());

Thanks for the suggestion. I did it your way.

> also don't forget to update the commit comment, it still says
> "Recursive_type_pair_iterator".

Updated.


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