Make merchant accessible in PlayerPurchaseEvent

Author: NoyException

paper-api/src/main/java/io/papermc/paper/event/player/PlayerPurchaseEvent.java

@@ -5,8 +5,10 @@
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.HandlerList;
 import org.bukkit.event.player.PlayerEvent;
+import org.bukkit.inventory.Merchant;
 import org.bukkit.inventory.MerchantRecipe;
 import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
 import org.jspecify.annotations.NullMarked;
 
 /**
@@ -17,20 +19,31 @@ public class PlayerPurchaseEvent extends PlayerEvent implements Cancellable {
 
     private static final HandlerList HANDLER_LIST = new HandlerList();
 
+    private final Merchant merchant;
     private boolean rewardExp;
     private boolean increaseTradeUses;
     private MerchantRecipe trade;
 
     private boolean cancelled;
 
     @ApiStatus.Internal
-    public PlayerPurchaseEvent(final Player player, final MerchantRecipe trade, final boolean rewardExp, final boolean increaseTradeUses) {
+    public PlayerPurchaseEvent(final Player player, final Merchant merchant, final MerchantRecipe trade, final boolean rewardExp, final boolean increaseTradeUses) {
         super(player);
+        this.merchant = merchant;
         this.trade = trade;
         this.rewardExp = rewardExp;
         this.increaseTradeUses = increaseTradeUses;
     }
 
+    /**
+     * Gets the merchant that the player is trading with
+     *
+     * @return the merchant
+     */
+    public @NotNull Merchant getMerchant() {
+        return merchant;
+    }
+
     /**
      * Gets the associated trade with this event
      *
@@ -45,7 +58,7 @@ public MerchantRecipe getTrade() {
      *
      * @param trade the trade to use
      */
-    public void setTrade(final MerchantRecipe trade) {
+    public void setTrade(@NotNull final MerchantRecipe trade) {
         Preconditions.checkArgument(trade != null, "Trade cannot be null!");
         this.trade = trade;
     }

paper-api/src/main/java/io/papermc/paper/event/player/PlayerTradeEvent.java

@@ -4,6 +4,7 @@
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.MerchantRecipe;
 import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
 import org.jspecify.annotations.NullMarked;
 
 /**
@@ -12,21 +13,25 @@
 @NullMarked
 public class PlayerTradeEvent extends PlayerPurchaseEvent {
 
-    private final AbstractVillager villager;
-
     @ApiStatus.Internal
     public PlayerTradeEvent(final Player player, final AbstractVillager villager, final MerchantRecipe trade, final boolean rewardExp, final boolean increaseTradeUses) {
-        super(player, trade, rewardExp, increaseTradeUses);
-        this.villager = villager;
+        super(player, villager, trade, rewardExp, increaseTradeUses);
+    }
+
+    @Override
+    public @NotNull AbstractVillager getMerchant() {
+        return (AbstractVillager) super.getMerchant();
     }
 
     /**
      * Gets the Villager or Wandering trader associated with this event
      *
      * @return the villager or wandering trader
+     * @see #getMerchant()
      */
+    @ApiStatus.Obsolete
     public AbstractVillager getVillager() {
-        return this.villager;
+        return getMerchant();
     }
 
 }

paper-server/patches/sources/net/minecraft/world/inventory/MerchantResultSlot.java.patch

@@ -12,8 +12,8 @@
 +        if (activeOffer != null && player instanceof net.minecraft.server.level.ServerPlayer serverPlayer) {
 +            if (this.merchant instanceof net.minecraft.world.entity.npc.AbstractVillager abstractVillager) {
 +                event = new io.papermc.paper.event.player.PlayerTradeEvent(serverPlayer.getBukkitEntity(), (org.bukkit.entity.AbstractVillager) abstractVillager.getBukkitEntity(), activeOffer.asBukkit(), true, true);
-+            } else if (this.merchant instanceof org.bukkit.craftbukkit.inventory.CraftMerchantCustom.MinecraftMerchant) {
-+                event = new io.papermc.paper.event.player.PlayerPurchaseEvent(serverPlayer.getBukkitEntity(), activeOffer.asBukkit(), false, true);
++            } else if (this.merchant instanceof org.bukkit.craftbukkit.inventory.CraftMerchantCustom.MinecraftMerchant minecraftMerchant) {
++                event = new io.papermc.paper.event.player.PlayerPurchaseEvent(serverPlayer.getBukkitEntity(), minecraftMerchant.getCraftMerchant(), activeOffer.asBukkit(), false, true);
 +            }
 +            if (event != null) {
 +                if (!event.callEvent()) {