Description:
------------
pg_fetch_all() documentation says:

"FALSE is returned if there are no rows in the result, or on any other error."

But NULL is returned if the argument is not a resource.

Reproduce code:
---------------
<?php
$a = pg_fetch_all('hello');
var_dump($a);
?>


Expected result:
----------------
Warning: pg_fetch_all() expects parameter 1 to be resource, string given in /tmp/t.php on line 2
bool(false)

Actual result:
--------------
Warning: pg_fetch_all() expects parameter 1 to be resource, string given in /tmp/t.php on line 2
NULL