Issue Description

The statement “To reimpose the limit, try using the ‘post_limits’ filter, or filter ‘pre_option_posts_per_rss’ and return -1” is unfortunately not correct. If you return -1 for ‘pre_option_posts_per_rss’, this value will be inserted directly at the LIMIT clause of the SQL query i.e. it will say something like LIMIT 0,-1 in the SQL query.
This leads to an SQL error so that no result is returned. With this filter it is mandatory that a number > 0 is returned. In case of doubt, you should use the PHP constant PHP_INT_MAX so that on most cases all entries are outputted.
It is extremely unlikely that there are more than 2147483647 (32-bit OS) or 9223372036854775807 (64-bit OS), but if there are, the return value would have to be increased accordingly.

Reported by mumbomedia via User Contributed Notes.

URL of the Page with the Issue

https://developer.wordpress.org/reference/classes/wp_query/#pagination-parameters

Section of Page with the issue

Pagination Parameters

Why is this a problem?

Causes an SQL error.

Suggested Fix

Remove or rephrase the sentence on how to change the post limit for feeds.

To reimpose the limit, try using the ‘post_limits’ filter, or filter ‘pre_option_posts_per_rss’ and return [a large number].