【WordPress備忘録】意図しないURLが投稿記事に表示されるときの回避方法

function post_related_thumbnail($atts, $content = null){
   　　 $content = do_shortcode($content);
	$content .= '<div class="trawell-section trawell-layout-b2 trawell-related">';
	$content .= '<div class="container">';
	$content .= '<div class="row">';
	if (!function_exists('is_countable')) {
      function is_countable($atts) {
	           $counter = count($atts);
	  }
	}else if (is_array($atts)) {
		$counter = count($atts);
	}
	for ($i = 0; $i < $counter ; $i++) {
		$p_id = $atts[$i];
		$post = get_post($p_id);
		$p_title = $post->post_title;
		/*$url = the_permalink($post); */
		$url = get_permalink($p_id);
		$excerpt = wp_trim_words ( strip_shortcodes( $post->post_content ), 80 );
        $trawell_featured_image = get_the_post_thumbnail($p_id, trawell_get_featured_image('trawell-b1-sid') );

		$content .= '<div class="col-12 inline-related">';
                $content .= '<article class="trawell-item row">';
		
		if ($trawell_featured_image):
		$content .= '<div class="col-5">';
			$content .= '<a href="' . $url . '" class="entry-image">'.trawell_wp_kses( $trawell_featured_image).'</a>';
		$content .= '</div>';	
	        endif;
		$content .= '<div class="col-7 no-left-padding">';
                 	$content .= '<div class="entry-header">';
			$content .= '<div class="entry-category color-text">'. trawell_get_category().'</div>';
			$content .= '<h3 class="entry-title h4 sm-h6"><a href="' . $url . '">'.$p_title.'</a></h3>';
			$content .= '<div class="entry-meta entry-meta-small">';
                   $content .= $excerpt;
            $content .= '</div>';
			$content .= '<p><a href="' . $url. '" class="green_link">この記事を読む</a></p>';
            $content .= '</div>';
            $content .= '</div>';
            $content .= '</article>';
		$content .= '</div>';
	}
	$content .= '</div>';
	$content .= '</div>';
	$content .= '</div>';
	return $content;
}
add_shortcode('related', 'post_related_thumbnail');

ob_start();
ob_get_clean();

/*$url = the_permalink($post); */
$url = get_permalink($p_id);