BUG #12609: use of regexp_matches drops rows when there is no match

The following bug has been logged on the website:

Bug reference:      12609
Logged by:          Trevor J Peschek
Email address:      trevor@adchemix.com
PostgreSQL version: 9.3.3
Operating system:   Red Hat 4.6.3-2
Description:

When using regexp_matches while referencing a location in the array, if the
match fails, the entire row is skipped instead of just a null for the column
using regexp_matches.  Example:

select
        aColumn,
        (regexp_matches(queryCol, '(https?)://(.*?)/(.*?)\?(.*?)'))[3]
from myTable

Even if the column with the regexp_matches returns a null, we would expect
the row to be populated with aColumn and then a null.  What happens though
is nothing is returned.