Come together with the global Drupal community in Rotterdam, 28 Sept – 1 Oct 2026. Sessions, contribution, connection, and Early Bird savings until 8 June.This is a long shot, but I think it is worth documenting the issue.
What I experience is that, the CAPTCHA image sometimes disappears or empty. But that happens very very rare. The one that disappears is only the image characters, the distortion image is still being displayed. If I forced to re-display the CAPTCHA image by refreshing the page 20 times for instance, sometimes I get the empty CAPTCHA image, but most of the time I don't get that. So I am not sure how to debug this kind of intermittent issue.
I am using php5-cgi and php5-gd version 5.2.10.
If anyone want to have a look, I use CAPTCHA image on http://thetwins.info/contact.html and http://thetwins.info/login.html. I also make a screenshot when the image characters disappear. Please find that attached.
| Comment | File | Size | Author |
|---|---|---|---|
| #3 | captcha_6.x-2.0-rc3_missing_1st_character_1.jpg | 131.9 KB | aryanto |
| #3 | captcha_6.x-2.0-rc3_missing_1st_character_2.jpg | 127.42 KB | aryanto |
| captcha_image_sometimes_disappears.jpg | 124.31 KB | aryanto |
Comments
Comment #1
soxofaan commentedVery weird.
And without access to your server, it's almost impossible for me to debug it,
if you are familiar with PHP/Drupal programming, you could try to debug it yourself?
Did you try if taking another font solves it?
Also, please try captcha 6.x-2.x versions, 6.x-1.x is practically unmaintained
Can you describe your setup too: operating system, PHP version, GD version, used font, ...?
Comment #2
aryanto commentedDo you mean that you need admin access to my Drupal setup and root access to my server? Well... I am sorry, I don't think I can give you that :)
I am not really good in PHP programming. But even if I were, I think it is quite hard to debug as the issue is really intermittent. Did you try to access the my pages containing the CAPTCHA image? How many time did you refresh the page until you get the problem? If you ever got the problem, could you please suggest me how to debug that? I have a test server to do that, do you think with Devel module I could catch the issue?
I don't think the issue has got to do with the font as usually the issues related to the font are persist.
I mentioned that I am using php5-cgi and php5-gd version 5.2.10. I am not really sure the exact version of the GD as phpnfo() only says "GD Version = 2.0 or higher". My Drupal 6.13 is running on a Debian Squeeze server with Lighttpd 1.4.23 and SQLite 3.6.17. And the font I am using is pala.ttf. Please let me know if you need more detail information.
In the mean time, I will try CAPTCHA version 6.x-2.x as you suggested. I will update you on this.
Comment #3
aryanto commentedHere is the update.
I just updated my CAPTCHA module to version 6.x-2.0-rc3. I didn't realise that version was just released yesterday.
The problem of all characters are missing from the CAPTCHA image, seems to be fixed in this release. But I got different problem, where sometimes the first character is missing. I tried to refresh the pages containing CAPTCHA image about 50 times, and I sometimes get this missing first character. I am sure that one character is missing as I set to display 5 characters, but only 4 being displayed. And the one which is missing, is definitely the first character as I saw that in the CAPTCHA image configuration page, i.e. the attached screenshot file: captcha_6.x-2.0-rc3_missing_1st_character_1.jpg. I also made another screenshot which is also attached.
I think this new issue has been reported on http://drupal.org/node/349218, but I am not sure if both issues have the same root cause. If so, I don't mind to have my issue report marked as duplicate.
Comment #4
soxofaan commentedyes, this is without a doubt a duplicate of #349218: Sometimes first character of image CAPTCHA is invisible: weird bug in PHP's bounding box calculation
Comment #5
jvieille commentedThe issue is still there in the last dev.
If "Character spacing" is set to "Wide" I get only one or two characters
Comment #6
soxofaan commented@jvieille: that's a different issue I think. Please open a separate issue thread and provide more info (e.g. which font you use, how many characters there should be in the image, give some screenshots, etc)