Description:
------------
Win32 GD imagepng() outputs bad data to the browser when the source or any included file has extraneous whitespace surrounding the <?php ?> tags. 

Tested Systems:

Windows 98 SE 
PHP 5CVS2006-Feb-15(snap), PHP 5.1.2, PHP 4.3.4RC1
MSIE 5.0, Firefox 1.0.6
	
Windows XP Home SP1
PHP 4.3.11, MSIE 6.0 (breaks on space|crlf before <?php, space+crlf after ?>)


Reproduce code:
---------------
test.php:

<?php 
// include("testinc.php");
$text = "Happy Happy Joy Joy";
$test = ImageCreate(160,24);
ImageFill($test,0,0,ImageColorAllocate($test,0,0,0));
ImageString($test,4,4,4,$text,ImageColorAllocate($test,255,255,255));
header("Content-type: image/png");
imagepng($test); 
?>

testinc.php:

<?php 
$gettysburg = "Four score and seven years ago..."; 
?>_ <-- note: insert whitespace (0x20) after closing tag

Expected result:
----------------
Run test.php as listed and the browser displays the image as expected. Uncomment the include file, save and run test.php again, and the browser displays a "broken picture" icon. If you remove the trailing space from testinc.php the browser displays the image, but if you insert a space or a carriage return before the opening tag of either file, the image is "broken" again. (Firefox gives you the message 'The image "http://localhost/test.php" cannot be displayed, because it contains errors' rather than a broken image icon, but the cause and effect are the same.)

Actual result:
--------------
Speculation: the problem is actually intermittent (or appears to be) but at least this is verifiable. I have a hunch that the extraneous whitespace is somehow finding its way to the output buffer as the source is being parsed.