#29482 [Opn]: imagecreatefrompng() throws fatal error (no warning) when opening broken images
ID: 29482
User updated by: troublegum at woltlab dot de
Reported By: troublegum at woltlab dot de
Status: Open
Bug Type: GD related
Operating System: Windows XP Professional
PHP Version: 5.0.0
New Comment:
# The mentioned image can be downloaded at:
http://webpm.woltlab.info/misc/bugs.php.net/29482_broken.png
# The appropriate testcase here:
http://webpm.woltlab.info/misc/bugs.php.net/29482_test1.php.txt
# A demo of this behavior (running php4.3.5 with gd 2.0.17
(compatible))
http://webpm.woltlab.info/misc/bugs.php.net/29482_test1.php
Previous Comments:
------------------------------------------------------------------------
[2004-08-04 02:46:38] troublegum at woltlab dot de
I got a PNG image, that works perfectly fine with getimagesize() (means
the correct values for width and height are being extracted), but
imagecreatefrompng() fails to open it (with the above error message).
So this is definately not an option to sort out images, that can't be
open with imagecreatefrompng().
If it's not a bug, then it's certainly an improvement for future php
versions.
------------------------------------------------------------------------
[2004-08-04 02:06:08] iliaa@php.net
Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at
http://www.php.net/manual/ and the instructions on how to
report
a bug at http://bugs.php.net/how-to-report.php
Use the getimagesize() function to validate the image first
if you are unsure about the file's contents.
------------------------------------------------------------------------
[2004-08-01 15:55:51] troublegum at woltlab dot de
Description:
------------
imagecreatefrompng() should not throw a fatal error
when opening broken image files. Instead, a warning would be much more
useful.
The following code is useless as the scripts dies without any output.
If I remove the @, it throws the following message:
---
Fatal error: imagecreatefrompng() [function.imagecreatefrompng]:
gd-png: fatal libpng error: Invalid chunk length. in
F:\htdocs\bug\read.php on line 3
---
imagecreatefrompng throws a warning when opening files that are no png
files ('broken.png' is not a valid PNG file) but not when the image
file is a png image, bug is broken for whatever reason.
---
OS: Windows XP Professional
Apache: 2.0.49
PHP: 5.0.0 as apache module
GD: bundled (2.0.23 compatible)
PNG Support: enabled
Reproduce code:
---------------
<?php
$filename = 'broken.png';
$imageResource = @imagecreatefrompng($filename);
if (!$imageResource) {
die('could not read ' . $filename . ' image');
}
else {
echo 'image ' . $filename . ' successfully read';
}
?>
Expected result:
----------------
could not read broken.png image
Actual result:
--------------
Fatal error: imagecreatefrompng() [function.imagecreatefrompng]:
gd-png: fatal libpng error: Invalid chunk length. in
F:\htdocs\bug\read.php on line 3
------------------------------------------------------------------------
--
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