Robert Haas <robertmh...@gmail.com> writes:
> On Thu, Jun 30, 2016 at 9:25 PM, Jim Nasby <jim.na...@bluetreble.com> wrote:
>> SELECT array_dims(pg_temp.bad()), array_dims('{}'::text[]);
>> array_dims | array_dims
>> ------------+------------
>> [1:0]      |
>> (1 row)

> Yeah, that's a bug.

It looks like this is because PLySequence_ToArray neglects to special-case
zero-element arrays.  We could fix it there, but this is not the first
such bug.  I wonder if we should change construct_md_array to force
zero-element arrays to be converted to empty arrays, rather than assuming
callers will have short-circuited the case earlier.  Something like

        /* fast track for empty array */
        if (ndims == 0)
                return construct_empty_array(elmtype);

        nelems = ArrayGetNItems(ndims, dims);

+       /* if caller tries to specify zero-length array, make it empty */
+       if (nelems <= 0)
+               return construct_empty_array(elmtype);
+
        /* compute required space */
        nbytes = 0;
        hasnulls = false;

But that might introduce new problems too, if any callers expect the
array dimensions to be exactly what they asked for.

                        regards, tom lane


-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers

Reply via email to