Run sync tasks scheduled for the same tick FIFO

src/main/java/org/bukkit/craftbukkit/v1_7_R4/scheduler/CraftScheduler.java

@@ -50,7 +50,10 @@ public class CraftScheduler implements BukkitScheduler {
     private final PriorityQueue<CraftTask> pending = new PriorityQueue<CraftTask>(10,
             new Comparator<CraftTask>() {
                 public int compare(final CraftTask o1, final CraftTask o2) {
-                    return (int) (o1.getNextRun() - o2.getNextRun());
+                    int value = (int) (o1.getNextRun() - o2.getNextRun());
+
+                    // If the tasks should run on the same tick they should be run FIFO
+                    return value != 0 ? value : o1.getTaskId() - o2.getTaskId();
                 }
             });
     /**