One permalink can be set more than once

The new snippet is ready. The hook is triggered after:

• new post is added & custom permalink generated
• existing post is updated via WordPress admin dashboard

function pm_force_unique_permalinks($post_id, $new_uri, $old_uri) {
	global $permalink_manager_uris;

	while(empty($new_unique_permalink)) {
		$duplicates = array_keys($permalink_manager_uris, $new_uri);

		if(is_array($duplicates)) {
			$duplicated_ids = array_flip($duplicates);

			// Ignore this particular post
			if(isset($duplicated_ids[$post_id])) {
				unset($duplicated_ids[$post_id]);
			}

			// Count duplicates
			$duplicates_count = count($duplicated_ids) + 1;

			// Add numeral prefix to the URL
			if($duplicates_count > 1) {
				preg_match('/(.*)-([\d]{1,3})$/', $new_uri, $out);
				
				if(!empty($out[2])) {
					$new_uri = sprintf('%s-%d', $out[1], (int) $out[2] + 1);
				} else {
					$new_uri = preg_replace('/(.+?)(\.[^\.]+$|$)/', '$1-' . $duplicates_count . '$2', $new_uri);
				}
			} else {
				$new_unique_permalink = $new_uri;
			}
		}
	}

	$permalink_manager_uris[$post_id] = $new_unique_permalink;
	update_option('permalink-manager-uris', $permalink_manager_uris);
}
add_action('permalink_manager_updated_post_uri', 'pm_force_unique_permalinks', 10, 3);
add_action('permalink_manager_new_post_uri', 'pm_force_unique_permalinks', 10, 3);