The next_posts_link() show me a aditional page in blank

Question

The description

Hi, I am using a custom post type and a loop through the values ​​I show.

I'm using a term ($ term) that comes from a previous page in the loop to only show related items.

Just for a test run I configured in the administration of wordpress in the reading section, show only two post.

I'm also using a custom post type associated taxonomy as follows:

<?php 
  // Argumentos del loop
  $argumentos = array (
    'post_type' => 'placas',
    'paged' => $paged,
    'tax_query' => array(
      array(
        'taxonomy' => 'firmas',
        'field' => 'slug',
        'terms' => $term
      )
    )
  );

  $query_productos= new WP_Query($argumentos);
?>

The pagination made ​​this way works well

<div class="nav-previous alignleft"><?php next_posts_link( 'Older posts' ); ?></div>
<div class="nav-next alignright"><?php previous_posts_link( 'Newer posts' ); ?></div>

The Problem

But I need to display 4 post, so try this.

This shows me 4 post related to the term

 <?php 
  // Argumentos del loop
  $argumentos = array (
    'post_type' => 'placas',
    'posts_per_page' => 4,
    'paged' => $paged,
    'tax_query' => array(
      array(
        'taxonomy' => 'firmas',
        'field' => 'slug',
        'terms' => $term
      )
    )
  );

  $query_productos= new WP_Query($argumentos);
 ?>

The problem is that the links next returns me an extra one, without content. Only have 6 post published and I should only have 2 pages for paging, but actually get 3 and the last third is empty.

How I can fix it so that only the necessary pages have not an extra that is empty?

Answer 1

The issue is that you are running a custom query ($query_productos), but your next_posts_link is using information from the main query ($wp_query) to determine whether or not to show a link to the next page.

See the example on next_posts_link for use with WP_Query, by passing max_num_pages from your custom query -

<?php next_posts_link( 'Older posts', $query_productos->max_num_pages ); ?>