Re: [HACKERS] [PATCH] Generic type subscripting

> On Thu, Dec 31, 2020 at 08:21:55PM +0100, Pavel Stehule wrote:
> čt 31. 12. 2020 v 15:27 odesílatel Dmitry Dolgov <9erthalion6(at)gmail(dot)com>
> napsal:
>
> the tests passed and filling gaps works well
>
> but creating empty objects doesn't work
>
> create table foo(a jsonb);
>
> insert into foo values('{}');
>
> postgres=# update foo set a['k'][1] = '20';
> UPDATE 1
> postgres=# select * from foo;
> ┌───────────────────┐
> │ a │
> ╞═══════════════════╡
> │ {"k": [null, 20]} │
> └───────────────────┘
> (1 row)
>
> it is ok
>
> postgres=# update foo set a['k3'][10] = '20';
> UPDATE 1
> postgres=# select * from foo;
> ┌───────────────────┐
> │ a │
> ╞═══════════════════╡
> │ {"k": [null, 20]} │
> └───────────────────┘
> (1 row)
>
> the second update was not successful

Right, it was working only if the source level is empty, thanks for
checking. I've found a bit more time and prepared more decent version
which covers all the cases I could come up with following the same
implementation logic. The first patch is the same though.