fix example URL, additional sanity check when updating dates

README.txt

@@ -15,7 +15,7 @@ If you have ongoing themes you write about on your site, you can use Threads to
 
 Another good usage of Threads is on a news site to track posts related to a single ongoing story. For example, a tech blog might create a thread to group stories about a product launch event. Several months later, stories about sales figures for the product might be added to the thread. By placing all of these posts in a thread, there is a useful visual way of browsing all of the posts.
 
-The timeline display of a thread is both responsive and retina (HiDPI) friendly. See an <a href="https://alexking.org/blog/thread/content">example here</a>.
+The timeline display of a thread is both responsive and retina (HiDPI) friendly. See an <a href="http://alexking.org/blog/thread/content">example here</a>.
 
 Developers, please contribute on <a href="https://github.com/crowdfavorite/wp-threads">GitHub</a>.
 

threads.php

@@ -273,14 +273,16 @@ function cfth_update_thread_date($post_id, $post) {
 // update each thread date with current date
 		foreach ($threads as $thread) {
 			$_post = cftpb_get_post($thread->term_id, 'threads');
-			$now = current_time('mysql');
-			if ($now > $_post->post_date) {
-				$data = array(
-					'ID' => $_post->ID,
-					'post_date' => $now,
-					'post_date_gmt' => current_time('mysql', 1),
-				);
-				wp_update_post($data);
+			if ($_post) {
+				$now = current_time('mysql');
+				if ($now > $_post->post_date) {
+					$data = array(
+						'ID' => $_post->ID,
+						'post_date' => $now,
+						'post_date_gmt' => current_time('mysql', 1),
+					);
+					wp_update_post($data);
+				}
 			}
 		}
 	}