is_home and is_frontpage always true

Question

I'm trying to limit the number of posts on the homepage but is_home() and is_frontpage() always seem to return true (even when I'm browsing /page/2/, /page/3/ and so on).

I've basically duplicated the twenty fifteen theme and trying to make my own based on that one. I deleted every function in functions.php (also removed any calls to those functions) and currently I only have this function in there:

add_action( 'pre_get_posts', 'limit_frontpage_posts' );

function limit_frontpage_posts( $query ) {

    if ( is_front_page() || is_home() ){
        $query->set( 'posts_per_page', 1 );
    }

  return $query;
}

Basically I want one post on the frontpage and on every other page whatever limit has been set in the admin panel. The code above is showing only one post on every page. Any idea's what's going wrong?

Answer 1

There's nothing wrong, the second page of your home page is still your home page. If you want to check if it's only the first page, check if ! is_paged().

That said, you can't just change posts per page and have it work properly, because when you're on the 2nd page and beyond, the post it starts on is calculated based on the current number of posts per page- WordPress doesn't know that your first page only had one post and the 2nd should start at post #2, it will just multiply posts per page by the page number, so posts will be skipped.

See this answer for an explanation and solution.