PaperMC/nms-patches/BlockDispenser.patch

--- a/net/minecraft/server/BlockDispenser.java
+++ b/net/minecraft/server/BlockDispenser.java
@@ -8,6 +8,7 @@
     public static final BlockStateBoolean TRIGGERED = BlockStateBoolean.of("triggered");
     public static final RegistryDefault<Item, IDispenseBehavior> REGISTRY = new RegistryDefault(new DispenseBehaviorItem());
     protected Random d = new Random();
+    public static boolean eventFired = false; // CraftBukkit
 
     protected BlockDispenser() {
         super(Material.STONE);
@@ -82,6 +83,7 @@
                 IDispenseBehavior idispensebehavior = this.a(itemstack);
 
                 if (idispensebehavior != IDispenseBehavior.NONE) {
+                    eventFired = false; // CraftBukkit - reset event status
                     tileentitydispenser.setItem(i, idispensebehavior.a(sourceblock, itemstack));
                 }