More reliable way to get author and autorurl (#546)

---------

Co-authored-by: Matt Wiebe <[email protected]>

Author: uk3

includes/class-shortcodes.php

@@ -390,7 +390,8 @@ public static function author( $atts, $content, $tag ) {
 			return '';
 		}
 
-		$name = \get_the_author_meta( 'display_name', $item->post_author );
+		$author_id = \get_post_field( 'post_author', $item->ID );
+		$name = \get_the_author_meta( 'display_name', $author_id );
 
 		if ( ! $name ) {
 			return '';
@@ -415,7 +416,8 @@ public static function authorurl( $atts, $content, $tag ) {
 			return '';
 		}
 
-		$url = \get_the_author_meta( 'user_url', $item->post_author );
+		$author_id = \get_post_field( 'post_author', $item->ID );
+		$url = \get_the_author_meta( 'user_url', $author_id );
 
 		if ( ! $url ) {
 			return '';

readme.txt

@@ -111,6 +111,7 @@ Project maintained on GitHub at [automattic/wordpress-activitypub](https://githu
 * Improved: better error messages if remote profile is not accessible
 * Improved: PHP 8.1 compatibility
 * Fixed: don't try to parse mentions or hashtags for very large (>1MB) posts to prevent timeouts
+* Improved: more reliable [ap_author], props @uk3
 
 = 1.0.10 =