BUG #8218: Error when querying an JSON data, 9.3beta

The following bug has been logged on the website:

Bug reference: 8218
Logged by: Daniel Zlatev
Email address: daniel(dot)zlatev(at)gmail(dot)com
PostgreSQL version: Unsupported/Unknown
Operating system: Windows
Description:

Dears,

today I was playing with some JSON data, and I have noticed something
strange.

1. I've created the follwing table:
CREATE TABLE products (
data JSON
);

2. Then inserting some data:
INSERT INTO products(data) VALUES('{"id": 1, "name": "shoes", "in_stock":
5}');
INSERT INTO products(data) VALUES('[1,2,3,4,5]');

3. Then i've run this SELECT statement
SELECT * FROM products WHERE (data->>'in_stock')::integer > 0

Output was:
[Err] ERROR: cannot extract field from a non-object

I can understand the reason behind this error(JSON array don't has fields),
but for me it is very logical postgres to exclude this row from the
returning set, rather to throw an error.

So that is it.

Best regards
Daniel