Merge pull request #305 from akirk/fix-edge-caching-problems

Fix Edge Caching Problems

includes/class-activitypub.php

@@ -39,6 +39,9 @@ class Activitypub {
 			return $template;
 		}
 
+		// Ensure that edge caches know that this page can deliver both HTML and JSON.
+		header( 'Vary: Accept' );
+
 		// check if user can publish posts
 		if ( \is_author() && ! user_can( \get_the_author_meta( 'ID' ), 'publish_posts' ) ) {
 			return $template;