From 9957f46302b558fb850e96363f5d4c61b6090263 Mon Sep 17 00:00:00 2001 From: Alphaesia Date: Fri, 23 Apr 2021 21:36:34 +1200 Subject: Fix duplicating /give items on item drop cancel (#5536) --- ...uplicating-give-items-on-item-drop-cancel.patch | 70 ++++++++++++++++++++++ 1 file changed, 70 insertions(+) create mode 100644 Spigot-Server-Patches/0707-Fix-duplicating-give-items-on-item-drop-cancel.patch diff --git a/Spigot-Server-Patches/0707-Fix-duplicating-give-items-on-item-drop-cancel.patch b/Spigot-Server-Patches/0707-Fix-duplicating-give-items-on-item-drop-cancel.patch new file mode 100644 index 0000000000..cee651ba1d --- /dev/null +++ b/Spigot-Server-Patches/0707-Fix-duplicating-give-items-on-item-drop-cancel.patch @@ -0,0 +1,70 @@ +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 +From: Alphaesia +Date: Fri, 23 Apr 2021 09:57:56 +1200 +Subject: [PATCH] Fix duplicating /give items on item drop cancel + +Fixes SPIGOT-2942 (Give command fires PlayerDropItemEvent, cancelling it causes item duplication). + +For every stack of items to give, /give puts the item stack straight +into the player's inventory. However, it also summons a "fake item" +at the player's location. When the PlayerDropItemEvent for this fake +item is cancelled, the server attempts to put the item back into the +player's inventory. The result is that the fake item, which is never +meant to be obtained, is combined with the real items injected directly +into the player's inventory. This means more items than the amount +specified in /give are given to the player - one for every stack of +items given. (e.g. /give @s dirt 1 gives you 2 dirt). + +While this isn't a big issue for general building usage, it can affect +e.g. adventure maps where the number of items the player receives is +important (and you want to restrict the player from throwing items). + +If there are any overflow items that didn't make it into the inventory +(insufficient space), those items are dropped as a real item instead +of a fake one. While cancelling this drop would also result in the +server attempting to put those items into the inventory, since it is +full this has no effect. + +Just ignoring cancellation of the PlayerDropItemEvent seems like the +cleanest and least intrusive way to fix it. + +diff --git a/src/main/java/net/minecraft/server/commands/CommandGive.java b/src/main/java/net/minecraft/server/commands/CommandGive.java +index 6685bf1757458d908e32d4069f7a8a22a28c28d7..a10207f7cb9455e29db7e6906cb2138ad5609a1f 100644 +--- a/src/main/java/net/minecraft/server/commands/CommandGive.java ++++ b/src/main/java/net/minecraft/server/commands/CommandGive.java +@@ -49,7 +49,7 @@ public class CommandGive { + + if (flag && itemstack.isEmpty()) { + itemstack.setCount(1); +- entityitem = entityplayer.drop(itemstack, false); ++ entityitem = entityplayer.drop(itemstack, false, false, true); // Paper - Fix duplicating /give items on item drop cancel + if (entityitem != null) { + entityitem.s(); + } +diff --git a/src/main/java/net/minecraft/world/entity/player/EntityHuman.java b/src/main/java/net/minecraft/world/entity/player/EntityHuman.java +index ec0956a98c133bcd3d4f92f696c667eab6ff98f1..3a62bde04d7fbb6c571cfef11d4f6891e11c7ac8 100644 +--- a/src/main/java/net/minecraft/world/entity/player/EntityHuman.java ++++ b/src/main/java/net/minecraft/world/entity/player/EntityHuman.java +@@ -642,6 +642,13 @@ public abstract class EntityHuman extends EntityLiving { + + @Nullable + public EntityItem a(ItemStack itemstack, boolean flag, boolean flag1) { ++ // Paper start - Fix duplicating /give items on item drop cancel ++ return this.drop(itemstack, flag, flag1, false); ++ } ++ ++ @Nullable ++ public EntityItem drop(ItemStack itemstack, boolean flag, boolean flag1, boolean alwaysSucceed) { ++ // Paper end + if (itemstack.isEmpty()) { + return null; + } else { +@@ -683,7 +690,7 @@ public abstract class EntityHuman extends EntityLiving { + PlayerDropItemEvent event = new PlayerDropItemEvent(player, drop); + this.world.getServer().getPluginManager().callEvent(event); + +- if (event.isCancelled()) { ++ if (event.isCancelled() && !alwaysSucceed) { // Paper - Fix duplicating /give items on item drop cancel + org.bukkit.inventory.ItemStack cur = player.getInventory().getItemInHand(); + if (flag1 && (cur == null || cur.getAmount() == 0)) { + // The complete stack was dropped -- cgit v1.2.3