Big avatar pics can crash Q&A

Fri, 27 May 2011 18:39:14 +0000

If users choose really big avatar files, this can lead to a crash of Q&A without any error message --> just a white screen.

The reason is the php function "$inimage=@imagecreatefromstring($imagedata);" used in qa-util-imgage.php.

The image is uncompressed converted in a variable to be stored in the database.
If the image size is bigger than the php memory limit (memory_limit) this leads to a memory overflow - and a white, blank screen for the user :(

[ x_size * y_size * bpp > memory_limit ]

To avoid this a modification in qa-page-account.php to check the uncompressed (!) picture size of the uploaded avatar pic can help:

original:

if (is_array(@$_FILES['file']) && $_FILES['file']['size'])
if (!qa_set_user_avatar($qa_login_userid, file_get_contents( _
                  $_FILES['file']['tmp_name']), $useraccount['avatarblobid']))
    $errors['avatar']=qa_lang_sub('users/avatar_not_read', implode( _
                   ', ', qa_gd_image_formats()));

modification:

if (is_array(@$_FILES['file']) && $_FILES['file']['size']){
//check image-size to prevent memory overrun
$t_imgsize=getimagesize($_FILES['file']['tmp_name']);
//uncompressed image larger than standard php memory_limit 128M
if (($t_imgsize[0] * $t_imgsize[1] * $t_imgsize['bits'] * $t_imgsize['channels'] / 8) _
     > 100000000){
    $errors['avatar']='image too big, please choose a smaller...';
}else{
    if (!qa_set_user_avatar($qa_login_userid, file_get_contents( _
                   $_FILES['file']['tmp_name']), $useraccount['avatarblobid']))
      $errors['avatar']=qa_lang_sub('users/avatar_not_read', implode( _
                     ', ', qa_gd_image_formats()));
}
}

You'll have to adjust the memory-limit to your individual setting of memory_limit in your php.ini ! Best way of cause is to retrieve the memory_limit online like described here: http://php.net/manual/en/function.ini-get.php

! attention: there are three line breaks due to the editor in the code which must be deleted again:
they are marked with the descender symbol " _ "

Image auto-resize function?

Sun, 03 Apr 2011 00:14:26 +0000

Hi there,

Is there any way to make images in answers auto-resized to fit with the default width of content.

Recently, I've found that when a member inserts large-size pictures in his post, those overlapped and hid the side-panel's contents:

http://chatscience.net/19/heterocyclic-chemistry-exercise

Therefore, I would like to know if there is way to make such images auto fitted.

Best regards.

Question2Answer Q&A - Recent questions tagged large-size

Big avatar pics can crash Q&A

Image auto-resize function?