Wordpress creates erroneous, non-ambiguous guid in RSS feeds

[CRCulver]

The RSS feed for my self-hosted Wordpress blog does not validate; feedvalidator.org gives the following error:

line 101, column 67: guid values must not be duplicated within a feed: ​http://www.christopherculver.com//.html (9 occurrences)

Indeed, for every post that is combined into the RSS feed, the guid element is exactly the same as shown in the error message, and the page title and the preceding part of the URL went missing somewhere along the way. Note that this may be related to the fact that in Settings -> Permalinks, I have set the following Custom structure: <siteurl> /%category%/%postname%.html

[stevenkword]

This appears to be a problem with your permalink structure. I'm guessing you have selected this structure to migrate from an older website, written in standard HTML.

I would recommend setting your permalink structure to one of the standard patterns and then use one of the URL redirection plugins, such as ​https://wordpress.org/plugins/safe-redirect-manager/, to handle the redirections.

Good luck!

[CRCulver]

No, you guess wrong, I'm afraid. My site has always been a Wordpress blog. I simply want that permalink structure -- which is a commonly used one -- and this permalink structure is provided to users through the Wordpress Settings -> Permalink screen. Clearly this is a simple bug in the RSS generation code that can be fixed, no need for users to turn to a plugin that competes in this regard with built-in functionality.

[nacin]

Correct, as weird as it is, ending a WP permalink structure in .html is valid and supported.

[stevenkword]

After digging in a little deeper, I'm having trouble reproducing the issue. Looking at the template code that is responsible for generating the feed, we find a method, the_guid, that is used to emit this value. The method takes the value from the guid column in the wp_posts table, applies filters hooked on get_the_guid, and then returns the value. I have not been able to find any core functionality hooked to this filter which could indicate a potential problem in a plugin or theme.

1.) What plugins do you have installed?
2.) Have you tried disabling all plugins, using a default theme, and refreshing the permalinks?
3.) What sort of values are you seeing in the guid column of the wp_posts table?

[CRCulver]

1) I typically run the plugins Akismet and Wordpress SEO.

2) Yes. I disabled all plugins, switched to the Twenty Fourteen theme, and refreshed the Permalinks by clicking "Save changes" in the Permalinks screen of the settings. There was no effect: the feed still fails to validate with a duplicated guid error.

3) Here we seem to be getting to the heart of the problem. Published posts all have the guid http://www.christopherculver.com//.html, while post revisions in the database have a guid of the type http://www.christopherculver.com//6592-revision-v1.... This is visible in the database a couple of years back, basically as far as I've had this permalink structure. (Furthermore, it is visible to a time before I installed the Wordpress SEO plugin, so I believe a plugin can be ruled out as the cause of this issue.)

[stevenkword]

Are there any posts rows that do not have that exact GUID? In other words, does it happen for a post you created 5 mins ago?

[stevenkword]

@CRCulver -- Could I get some feedback on the previous question? At the moment, I'm still unable to reproduce the problem.

[CRCulver]

Sorry, but I ultimately found that this problem was due to a mistake made in my own functions.php file. So, I am marking this bug as invalid and you can close it.

[stevenkword]

@CRCulver Sounds good thanks for the feedback!