Ticket #6966: cron-ignore-duplicate-events-r7916.3.patch

wp-includes/cron.php

@@ -1 +1 @@
 <?php
 
 function wp_schedule_single_event( $timestamp, $hook, $args = array()) {
+        // don't schedule a duplicate if there's already an identical event due in the next 10 minutes
+        $next = wp_next_scheduled($hook, $args);
+        if ( $next && $next <= $timestamp + 600 )
+                return;
+                
         $crons = _get_cron_array();
         $key = md5(serialize($args));
         $crons[$timestamp][$hook][$key] = array( 'schedule' => false, 'args' => $args );