--- feedapi.module (saved version)
+++ feedapi.module (current document)
@@ -708,7 +708,10 @@
   if (!$time_limit) {
     $time_limit = time() + (variable_get('feedapi_cron_percentage', 15) / 100) * ini_get('max_execution_time');
     // However, check for left time, maybe some other cron processing already occured
-    $time_limit = min($time_limit, variable_get('cron_semaphore', 0) + ini_get('max_execution_time'));
+    $cron_semaphore = variable_get('cron_semaphore', 0);
+    if ($cron_semaphore) {
+      $time_limit = min($time_limit, $cron_semaphore + ini_get('max_execution_time'));
+    }
     timer_start('feedapi_cron');
   }
   return max($time_limit - time(), 0);