Ashley Sheridan wrote:
On Sun, 2009-11-15 at 15:07 -0500, Ben wrote:
On my site I have a web form for users to upload graphics, however there are constraints on the size allowed. Recently, a user has been having problems, because the code is reporting the wrong size - a size too small to be allowed! They sent me a copy of the image so I could confirm the error, and I have: even though the image is a 32x32 image (2-frame animated GIF, if it matters), imagesx() and imagesy() report that the image is 30x24! I have never had this problem before (or, at least, no one has reported it to me) so I'm tempted to think that it's a bug in PHP, or (more likely) I am missing something crucial...


The relevant code:

if($itype == 'image/gif')
   $img = imagecreatefromgif($_FILES['file']['tmp_name']);
else if($itype == 'image/png' || $itype == 'image/x-png')
   $img = imagecreatefrompng($_FILES['file']['tmp_name']);

// note: we do not get here if($itype != 'image/gif' && $itype !=
// 'image/png' && $itype != 'image/x-png'), so the problem should not
// lie with an image type we were not expecting

$w = imagesx($img);
$h = imagesy($img);

if(!(($w == 48 && $h == 48) || ($w >= 4 && $w <= 48 && $h == 32)))
{
   $error = 'The graphic\'s dimensions are not correct (' .
            $w . 'x' . $h . ').';
}
else
{
   ...
}

yes, the logic wants either a 48x48 graphic, or a 4x32 to 48x32 graphic.

I'd be happy to link the animated GIF in question... just in case there was a problem with the GIF itself, I tried opening it up in an (old) version of Fireworks, and re-exporting it, but the problem remains.

besides the possibility of a bug in PHP, I'm wondering if I need to handle animated GIFs differently, or something like that? but again, this code has been running for... 3ish years without a problem like this ever being reported... quite confusing.


If you could link the gif I think that would help.

Also, just to point out, the comment in the script is wrong, if the
image is neither png or gif, the rest of the script will still be
parsed. The if logic is like this:

if($itype == 'image/gif')
    $img = imagecreatefromgif($_FILES['file']['tmp_name']);
else
    if($itype == 'image/png' || $itype == 'image/x-png')
        $img = imagecreatefrompng($_FILES['file']['tmp_name']);



everything after that is executed

perhaps you wanted something like this:

if($itype == 'image' || $itype == 'image/png' || $itype ==
'image/x-png')
{
    if($itype == 'image/gif')
        $img = imagecreatefromgif($_FILES['file']['tmp_name']);
    if($itype == 'image/png' || $itype == 'image/x-png')
        $img = imagecreatefrompng($_FILES['file']['tmp_name']);

    // execute the rest of the image checking script
}


Thanks,
Ash
http://www.ashleysheridan.co.uk




what I meant by the comment, is that that previous code DOES exist... to assure you that the problem isn't in having $img unset, or something along those lines. (I added in the comment after the fact.)

I have uploaded the image causing the problem here: www.telkoth.net/temp/radioactive-bread-eek.gif

I should also add: I have ended up working around the problem by using getimagesize() instead; that function is reporting the correct width and height. this furthers my belief that there's a bug somewhere with imagesx(), imagesy() or imagecreatefromgif()...

--
PHP General Mailing List (http://www.php.net/)
To unsubscribe, visit: http://www.php.net/unsub.php

Reply via email to