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> N = new RegistryDefault(new DispenseBehaviorItem());
     protected Random O = new Random();
+    public static boolean eventFired = false; // CraftBukkit
 
     protected BlockDispenser() {
         super(Material.STONE);
@@ -83,6 +84,7 @@
 
                 if (idispensebehavior != IDispenseBehavior.a) {
                     ItemStack itemstack1 = idispensebehavior.a(sourceblock, itemstack);
+                    eventFired = false; // CraftBukkit - reset event status
 
                     tileentitydispenser.setItem(i, itemstack1.count <= 0 ? null : itemstack1);
                 }