From e3bdc53bea8fdc1ca8755691b293710d41ebe656 Mon Sep 17 00:00:00 2001
From: Cobianzo <cobianzo@gmail.com>
Date: Wed, 2 Aug 2023 20:02:57 +0100
Subject: [PATCH] 975-verification with isset before using properties

---
 template-tags.php | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/template-tags.php b/template-tags.php
index ab28b707..a3f9d6a0 100644
--- a/template-tags.php
+++ b/template-tags.php
@@ -73,7 +73,8 @@ function is_coauthor_for_post( $user, $post_id = 0 ) {
 	}
 
 	foreach ( $coauthors as $coauthor ) {
-		if ( $user == $coauthor->user_login || $user == $coauthor->linked_account ) {
+		if ( ( isset( $coauthor->user_login ) && $user == $coauthor->user_login ) 
+			|| ( isset( $coauthor->linked_account ) && $user == $coauthor->linked_account ) ) {
 			return true;
 		}
 	}