Description:
------------
when using default charset
CP850 on my system
some characters "?" isn't printed with imagestring() function

how to show the default charset used by gd????
this can make my bug no more a bug
with a workaround i could change imagestring to image_string and make the correct charset 
thanks

Reproduce code:
---------------
<?
function image_cp_text($string){
	$default=iconv_get_encoding('internal_encoding');
//CP850
//	$str=$string;
	$str=iconv($default,"CP850",$string);
	return($str);
}
$im = imagecreate(100, 30);
$bg = imagecolorallocate($im, 255, 255, 255);
$textcolor = imagecolorallocate($im, 0, 0, 255);
imagestring($im, 5, 0, 0, image_cp_text("?"), $textcolor);
header("Content-type: image/jpeg");
imagejpeg($im);
?>

Expected result:
----------------
image with all characters (?)

Actual result:
--------------
none blank image