#23747 [Fbk->Opn]: GD-PNG fatal error
| From: | wez@php.net | Date: | Fri, 23 May 2003 11:50:01 +0000 |
| Subject: | #23747 [Fbk->Opn]: GD-PNG fatal error | ||
| References: | 1 | Groups: | php.doc |
| Request: | Send a blank email to phpdoc+get-969353799@lists.php.net to get a copy of this message | ||
ID: 23747
Updated by: wez@php.net
Reported By: rryda at mgedata dot cz
-Status: Feedback
+Status: Open
-Bug Type: GD related
+Bug Type: Documentation problem
Operating System: Windows 2000
PHP Version: 4.3.2RC4
New Comment:
Not really a bug; fread() will now (correctly!) return data in packet
sized chunks when reading from network streams, as it did in PHP 4.2.x
and earlier.
Technically, your script is broken; you should either do this:
<?php
$data = "";
$fp = fopen("http://....");
do {
$chunk = fread($fp, 8192);
if (strlen($chunk) == 0) {
break;
}
$data .= $chunk;
} while (true);
fclose($fp);
?>
this:
<?php
$data = file_get_contents("http://...");
?>
or this:
<?php
copy("http://...", tempnam("", "gd"));
?>
I'm making this a documentation problem, because the fread() manual
page has never mentioned this fact, despite it being the behaviour
since forever.
One final note; the file_get_contents() and copy() functions were
themselves suffering from a similar problem to that of your script;
I've committed a fix to CVS, so you need to either use the fread() loop
approach, or get the next stable snapshot (due in an hour or so).
Previous Comments:
------------------------------------------------------------------------
[2003-05-22 08:13:07] derick@php.net
It just looks like your image is broken, can you put up a runnable
script + image in a tarball (or send it to me by mail) to verify?
Derick
------------------------------------------------------------------------
[2003-05-22 06:15:23] rryda at mgedata dot cz
More info:
- PHP is run as CGI
- using original windows binary pack
- php_gd2.dll from original windows binary pack
- web server: Apache 2.0.45
Imagecreatefrompng() is used in following code:
//$image_file_url ... URL to the source 24-bit PNG file
$image_base = ImageCreateTrueColor($map_width, $map_height);
$white = ImageColorExact($image_base, 255, 255, 255);
ImageFill($image_base, 0, 0, $white);
// ........
$input = fopen($image_file_url, "rb");
$image_data = fread($input, 2000000);
fclose($input);
$image_file = tempnam("", "gd".rand(0, 10000));
$output = fopen($image_file, "w+b");
fwrite($output, $image_data);
fclose($output);
$image_tmp = ImageCreateFromPNG($image_file); // ERROR
// ........
------------------------------------------------------------------------
[2003-05-22 05:56:11] derick@php.net
Not enough information was provided for us to be able
to handle this bug. Please re-read the instructions at
http://bugs.php.net/how-to-report.php
If you can provide more information, feel free to add it
to this bug and change the status back to "Open".
Thank you for your interest in PHP.
------------------------------------------------------------------------
[2003-05-22 02:33:22] rryda at mgedata dot cz
Fatal error: imagecreatefrompng(): gd-png: fatal libpng error: IDAT:
CRC error in .....
The error appears only if PHP is run as CGI (php.exe).
This functionality was used in 4.3.2RC3 successfully.
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/?id=23747&edit=1