PostgreSQL error with concat while viewing images

Drupal throws the following error:

* warning: pg_query() [function.pg-query]: Query failed: ERROR: function concat(text) does not exist HINT: No function matches the given name and argument types. You may need to add explicit type casts. in /usr/share/drupal5/includes/database.pgsql.inc on line 125.
* user warning: query: SELECT COUNT(n.nid) FROM node n INNER JOIN term_node tn ON n.nid = tn.nid WHERE n.type <> 'acidfree' AND tn.tid = 2 AND (n.moderate = 0 AND n.status = 1) AND CONCAT(LPAD(9999999999 - n.nid, 10, '0')) < '9999999922' in /usr/share/drupal5/includes/database.pgsql.inc on line 144.

The reason is that Drupal defines only a function for concat(text,text) and not for concat(text).

The attached patch solves that problem.