Re: json_query conditional wrapper bug

On 28.08.24 11:21, Peter Eisentraut wrote:
> These are ok:
> 
> select json_query('{"a": 1, "b": 42}'::jsonb, 'lax $.b' without wrapper);
>   json_query
> ------------
>   42
> 
> select json_query('{"a": 1, "b": 42}'::jsonb, 'lax $.b' with 
> unconditional wrapper);
>   json_query
> ------------
>   [42]
> 
> But this appears to be wrong:
> 
> select json_query('{"a": 1, "b": 42}'::jsonb, 'lax $.b' with conditional 
> wrapper);
>   json_query
> ------------
>   [42]
> 
> This should return an unwrapped 42.

If I make the code change illustrated in the attached patch, then I get 
the correct result here.  And various regression test results change, 
which, to me, all look more correct after this patch.  I don't know what 
the code I removed was supposed to accomplish, but it seems to be wrong 
somehow.  In the current implementation, the WITH CONDITIONAL WRAPPER 
clause doesn't appear to work correctly in any case I could identify.