Wordpress sticky posts and "posts_per_page" confusing

Question

I have a custom loop with this args:

$sticky = count(get_option('sticky_posts'));
$main_loop = array (
    'posts_per_page' => 4 - $sticky
);

I want to do the following:

• 1 sticky post: i want to show 3 posts + the sticky post
• 2 sticky posts: i want to show 2 posts + the 2 sticky posts
• 3 sticky posts: i want to show 1 posts + the 3 sticky posts
• 4 sticky posts: i want to show only the 4 sticky posts

But i won't get it to work. At the moment i have the following situation:

• 1 sticky post from 3 latest posts (1,2 or 3): i have one sticky post + 2 posts
• 1 sticky post from the fourth (or older) posts (4,5,6 ...): i have 1 sticky post + 3 posts (like i want it)
• 2 sticky posts from the fourth (or older) posts (4,5,6 ...): i have 2 sticky post + 2 posts (like i want it)
• 3 sticky posts from the fourth (or older) posts (4,5,6 ...): i have 3 sticky post + 1 post (like i want it)
• 4 sticky posts from the fourth (or older) posts (4,5,6 ...): i have 4 sticky post + 3 posts (but i want to show max. 4 posts)

In short: When i stick posts from the latest 3 posts it is not working and when i stick more than 3 posts it is not working.

This is the full loop:

<section>
<h2>Aktuelles</h2>
<?php
$sticky = count(get_option('sticky_posts'));
// WP_Query arguments
$main_loop = array (
'posts_per_page' => 4 - $sticky
);

// The Query
$query = new WP_Query( $main_loop );

// The Loop
while ( $query->have_posts() ) : $query->the_post(); ?>
<h3><?php the_title(); ?></h3>
<?php the_excerpt(); ?>

<?php endwhile; wp_reset_postdata(); ?>
</section>

Answer 1

Since I found no answer to this question I used another approach with 2 loops combined that always show 4 posts. The trick is to substract the sticky post count from the second loop.

<?php 
    $sticky = count(get_option('sticky_posts'));
    if ($sticky > 0) { 
?>
<?php   
    // First loop with sticky posts
    $main_loop_s = array (
        'posts_per_page'         => $sticky,
        'post__in' => get_option('sticky_posts'),
    );
    // The Query
    $do_not_duplicate = array();
    $query = new WP_Query( $main_loop_s );
    // The Loop
    while ( $query->have_posts() ) : $query->the_post(); $do_not_duplicate[] = $post->ID; ?>
    <h3><?php the_title(); ?></h3>      
    <?php endwhile;
?>
<?php // stickycheck end 
    } 
?>
<?php 
    $sticky = count(get_option('sticky_posts'));
    if ($sticky < 4) { 
?>
<?php
    $allstickys = 4 - $sticky;
    // Second loop with rest of posts up to 4
    $main_loop_ns = array (
        'posts_per_page'         => $allstickys,
        'offset'                 => $sticky,
        'post__not_in'           => $do_not_duplicate
    ); 
    // The Query
    $query = new WP_Query( $main_loop_ns );
    // The Loop
    while ( $query->have_posts() ) : $query->the_post(); ?>
        <h3><?php the_title(); ?></h3>          
    <?php endwhile; wp_reset_postdata();
?>
<?php // stickycheck end 
    } 
?>