PaperMC/nms-patches/ItemFishingRod.patch

--- a/net/minecraft/server/ItemFishingRod.java
+++ b/net/minecraft/server/ItemFishingRod.java
@@ -1,5 +1,7 @@
 package net.minecraft.server;
 
+import org.bukkit.event.player.PlayerFishEvent; // CraftBukkit
+
 public class ItemFishingRod extends Item {
 
     public ItemFishingRod() {
@@ -15,9 +17,18 @@
             itemstack.damage(i, entityhuman);
             entityhuman.bw();
         } else {
+            // CraftBukkit start
+            EntityFishingHook hook = new EntityFishingHook(world, entityhuman);
+            PlayerFishEvent playerFishEvent = new PlayerFishEvent((org.bukkit.entity.Player) entityhuman.getBukkitEntity(), null, (org.bukkit.entity.Fish) hook.getBukkitEntity(), PlayerFishEvent.State.FISHING);
+            world.getServer().getPluginManager().callEvent(playerFishEvent);
+
+            if (playerFishEvent.isCancelled()) {
+                return itemstack;
+            }
+            // CraftBukkit end
             world.makeSound(entityhuman, "random.bow", 0.5F, 0.4F / (ItemFishingRod.g.nextFloat() * 0.4F + 0.8F));
             if (!world.isClientSide) {
-                world.addEntity(new EntityFishingHook(world, entityhuman));
+                world.addEntity(hook); // CraftBukkit - moved creation up
             }
 
             entityhuman.bw();