Description:
------------
Calling dba functions (e.g. dba_exists/dba_insert) with a non-string key causes 
the key to be cast to a string.  This also affects any variables that are copies 
of the key variable.

This seems to be independent of database type - tested with db4 and flatfile 
databases.

Test script:
---------------
<?php

$db = dba_open('/tmp/testdb', 'c', 'flatfile');

$i = 1; //use integer key
$j = $i; //copy by value

echo gettype($i)."\n";
echo gettype($j)."\n";

dba_exists($i, $db);

echo gettype($i)."\n";
echo gettype($j)."\n";


Expected result:
----------------
integer
integer
integer
integer


Actual result:
--------------
integer
integer
string
string