For a while I’ve been noticing a lack of pingbacks from people linking to me. At first I put it down to people just not linking to me, but then after discussions with a colleague today I realised I didn’t have that annoying problem of them happening when I link to my own posts. I tested further and realised they weren’t working at all.
I debugged the issue using the good old “print debug messages all over the place” method – crude but effective. I started in xmlrpc.php and discovered that it was stopping at this line:
$comment_ID = wp_new_comment($commentdata);
This meant it was getting as far as trying to post the comment. It was then that I had a lightbulb moment. What would be stopping comments being posted? My captcha to stop comment spam (has it really been three years since I set that up?), that’s what!
My colleague has been using a numerical captcha-style plugin called Math Comment Spam Protection (MCSP) instead. I did a quick comparison between it and the SecureImage plugin and fairly quickly found the difference. This is from the MCSP plugin:
if (Â ( !isset($user_ID) ) && ( $comment_data['comment_type'] == '' ) ) {
// Do not check if the user is registered & do not check trackbacks/pingbacks
By comparison, the SecureImage plugin only checked if the user is registered:
// If the user is not logged in check the security code
if ( !$user_ID ) {
The fix looks simple. But, given the lack of updates for SecureImage I decided it was time to move on. So now I have the MCSP plugin instead, and pingbacks are once again working.
I just have one request to make. Can anyone who’s linked to me in the last three years please try again? 
Related posts:
- An end to comment spam I finally decided to put an end to comment spam – I’ve installed a captcha. Whilst I was away on holiday I received around 3-5 spams a day, so rather than just deleting them I figured I needed to prevent them. The wordpress docs are a really useful resource. I decided to go with SecureImage [...]...
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Tags: captcha, comment spam, Math Comment Spam Protection, mcsp, pingback, SecureImage, spam
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on Tuesday, March 24th, 2009 at 5:42 pm and is filed under Computing.
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Broken pingbacks – what’s to blame?
For a while I’ve been noticing a lack of pingbacks from people linking to me. At first I put it down to people just not linking to me, but then after discussions with a colleague today I realised I didn’t have that annoying problem of them happening when I link to my own posts. I tested further and realised they weren’t working at all.
I debugged the issue using the good old “print debug messages all over the place” method – crude but effective. I started in xmlrpc.php and discovered that it was stopping at this line:
This meant it was getting as far as trying to post the comment. It was then that I had a lightbulb moment. What would be stopping comments being posted? My captcha to stop comment spam (has it really been three years since I set that up?), that’s what!
My colleague has been using a numerical captcha-style plugin called Math Comment Spam Protection (MCSP) instead. I did a quick comparison between it and the SecureImage plugin and fairly quickly found the difference. This is from the MCSP plugin:
By comparison, the SecureImage plugin only checked if the user is registered:
The fix looks simple. But, given the lack of updates for SecureImage I decided it was time to move on. So now I have the MCSP plugin instead, and pingbacks are once again working.
I just have one request to make. Can anyone who’s linked to me in the last three years please try again?
Related posts:
Tags: captcha, comment spam, Math Comment Spam Protection, mcsp, pingback, SecureImage, spam
This entry was posted on Tuesday, March 24th, 2009 at 5:42 pm and is filed under Computing. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.