301 infinite redirect loop error on SOME posts

[sveralex]

I have thousands posts in my web site. Most of post URLs work great, however for some unknown (to me) reason many of them do not, resulting in:
*
This webpage has a redirect loop
ERR_TOO_MANY_REDIRECTS:
*
Below are a few samples of such "bad" links:
---
​http://www.greenlightelectronics.com/electronic-part/MT49H16M36FM25A
​http://www.greenlightelectronics.com/electronic-part/NIS5101E2T1G
​http://www.greenlightelectronics.com/electronic-part/SEL3811B3125000
​http://www.greenlightelectronics.com/electronic-part/LFE2M100E7FN900C
​http://www.greenlightelectronics.com/electronic-part/MPC8360ZUALFHA
​http://www.greenlightelectronics.com/electronic-part/EDFABA25SCAPCA11SNMP
​http://www.greenlightelectronics.com/electronic-part/DWDMG10432TEJ01
​http://www.greenlightelectronics.com/electronic-part/XC6VCX195T2FFG784I
​http://www.greenlightelectronics.com/electronic-part/WINTC1C16091LCUPC
​http://www.greenlightelectronics.com/electronic-part/100833351128RLF
​http://www.greenlightelectronics.com/electronic-part/M3CWK2640K
​http://www.greenlightelectronics.com/electronic-part/LM555CN
​http://www.greenlightelectronics.com/electronic-part/XC5VLX155T1FF1136C
---
Please advice what is wrong in these post links.

And here is a sample of a good link, there are thousands of them:
​http://www.greenlightelectronics.com/electronic-part/6MBP150NA060

---
In my Permalink Settings I have:
Custom Structure : /electronic-part/%postname%

--
Thank you

[Clorith]

Hi and welcome to Trac.

Since it's not a consistent problem, it sounds like a support question, and not a core issue. Trac is intended for organizing the work on features and problems with WordPress core.

For support requests please see our forums at ​https://wordpress.org/support where someone will be able to assist you and go through proper troubleshooting steps to help you sort this out.

[sveralex]

I'm not sure you're right.
Just found this patch (CORE!), which helped me. But I'm not sure if it does not impact on other functions.

Index: wp-includes/query.php
===================================================================
--- wp-includes/query.php	(revision 26965)
+++ wp-includes/query.php	(working copy)
@@ -3923,6 +3923,10 @@
 
 		$query = $wpdb->prepare("SELECT post_id FROM $wpdb->postmeta, $wpdb->posts WHERE ID = post_id AND post_type = %s AND meta_key = '_wp_old_slug' AND meta_value = %s", $post_type, $wp_query->query_vars['name']);
 
+		// Prevent a simple redirect loop due to values in '_wp_old_slug' not deleted
+		// when in an unpublished status.
+		$query .= $wpdb->prepare(" AND post_name != %s", $wp_query->query_vars['name']);
+
 		// if year, monthnum, or day have been specified, make our query more precise
 		// just in case there are multiple identical _wp_old_slug values
 		if ( '' != $wp_query->query_vars['year'] ) 

[SergeyBiryukov]

Hi @sveralex,

Thanks for the report, we're already tracking this issue in #35012 and #35031.