From fc10d576b3d09d06db5582b291dd01567dce5ed6 Mon Sep 17 00:00:00 2001
From: Shane Freeder <theboyetronic@gmail.com>
Date: Sun, 11 Feb 2018 10:43:46 +0000
Subject: [PATCH] Extend Player Interact cancellation

GUIs are opened on the client, meaning that the server cannot block them from opening,
However, it is possible to close these GUIs from the server.

Flower pots are also not updated on the client when interaction is cancelled, this patch
also resolves this.

Update adjacent blocks of doors, double plants, pistons and beds
when cancelling interaction.

diff --git a/src/main/java/net/minecraft/server/PlayerInteractManager.java b/src/main/java/net/minecraft/server/PlayerInteractManager.java
index 55e45f84ca..e83b4fb4b0 100644
--- a/src/main/java/net/minecraft/server/PlayerInteractManager.java
+++ b/src/main/java/net/minecraft/server/PlayerInteractManager.java
@@ -110,6 +110,7 @@ public class PlayerInteractManager {
         if (event.isCancelled()) {
             // Let the client know the block still exists
             ((EntityPlayer) this.player).playerConnection.sendPacket(new PacketPlayOutBlockChange(this.world, blockposition));
+            cancelBreakBlock(blockposition, this.world.getType(blockposition)); // Paper - Avoid visual issues on the client
             // Update any tile entity data for this block
             TileEntity tileentity = this.world.getTileEntity(blockposition);
             if (tileentity != null) {
@@ -249,6 +250,33 @@ public class PlayerInteractManager {
         return flag;
     }
 
+    // Paper start - Extra method to avoid visual issues on the client when cancelling block breaks
+    private void cancelBreakBlock(BlockPosition position, IBlockData data) {
+        Block block = data.getBlock();
+        // Send other half of the door
+        if (block instanceof BlockDoor) {
+            boolean bottom = data.get(BlockDoor.HALF) == BlockPropertyDoubleBlockHalf.LOWER;
+            this.player.playerConnection.sendPacket(new PacketPlayOutBlockChange(world, bottom ? position.up() : position.down()));
+        } else if (block instanceof BlockTallPlant) {
+            boolean bottom = data.get(BlockTallPlant.HALF) == BlockPropertyDoubleBlockHalf.LOWER;
+            this.player.playerConnection.sendPacket(new PacketPlayOutBlockChange(world, bottom ? position.up() : position.down()));
+        } else if (block instanceof BlockPistonExtension) {
+            BlockPosition piston = position.shift(data.get(BlockPistonExtension.FACING).opposite());
+            this.player.playerConnection.sendPacket(new PacketPlayOutBlockChange(world, piston));
+        } else if (block instanceof BlockBed) {
+            // Restore other half of bed
+            boolean foot = data.get(BlockBed.PART) == BlockPropertyBedPart.FOOT;
+            BlockPosition otherBlock = position.shift(foot ? data.get(BlockBed.FACING) : data.get(BlockBed.FACING).opposite());
+            this.player.playerConnection.sendPacket(new PacketPlayOutBlockChange(world, otherBlock));
+
+            TileEntity tileentity = this.world.getTileEntity(otherBlock);
+            if (tileentity != null) {
+                this.player.playerConnection.sendPacket(tileentity.getUpdatePacket());
+            }
+        }
+    }
+    // Paper end
+
     public boolean breakBlock(BlockPosition blockposition) {
         IBlockData iblockdata = this.world.getType(blockposition);
         // CraftBukkit start - fire BlockBreakEvent
@@ -297,11 +325,7 @@ public class PlayerInteractManager {
                 }
                 // Let the client know the block still exists
                 ((EntityPlayer) this.player).playerConnection.sendPacket(new PacketPlayOutBlockChange(this.world, blockposition));
-                // Send other half of the door
-                if (nmsBlock instanceof BlockDoor) {
-                    boolean bottom = nmsData.get(BlockDoor.HALF) == BlockPropertyDoubleBlockHalf.LOWER;
-                    ((EntityPlayer) this.player).playerConnection.sendPacket(new PacketPlayOutBlockChange(world, bottom ? blockposition.up() : blockposition.down()));
-                }
+                cancelBreakBlock(blockposition, nmsData); // Paper - Move cancellation code to extra "cancelBreakBlock" method
                 // Update any tile entity data for this block
                 TileEntity tileentity = this.world.getTileEntity(blockposition);
                 if (tileentity != null) {
@@ -459,7 +483,25 @@ public class PlayerInteractManager {
                 ((EntityPlayer) entityhuman).playerConnection.sendPacket(new PacketPlayOutBlockChange(world, bottom ? blockposition.up() : blockposition.down()));
             } else if (iblockdata.getBlock() instanceof BlockCake) {
                 ((EntityPlayer) entityhuman).getBukkitEntity().sendHealthUpdate(); // SPIGOT-1341 - reset health for cake
+            // Paper start  - extend Player Interact cancellation // TODO: consider merging this into the extracted method
+            } else if (iblockdata.getBlock() instanceof BlockStructure) {
+                    ((EntityPlayer) entityhuman).playerConnection.sendPacket(new PacketPlayOutCloseWindow());
+            } else if (iblockdata.getBlock() instanceof BlockCommand) {
+                    ((EntityPlayer) entityhuman).playerConnection.sendPacket(new PacketPlayOutCloseWindow());
+            } else if (iblockdata.getBlock() instanceof BlockFlowerPot) {
+                // Send a block change to air and then send back the correct block, just to make the client happy
+                PacketPlayOutBlockChange packet = new PacketPlayOutBlockChange(this.world, blockposition);
+                packet.block = Blocks.AIR.getBlockData();
+                this.player.playerConnection.sendPacket(packet);
+
+                this.player.playerConnection.sendPacket(new PacketPlayOutBlockChange(this.world, blockposition));
+
+                TileEntity tileentity = this.world.getTileEntity(blockposition);
+                if (tileentity != null) {
+                    player.playerConnection.sendPacket(tileentity.getUpdatePacket());
+                }
             }
+            // Paper end - extend Player Interact cancellation
             ((EntityPlayer) entityhuman).getBukkitEntity().updateInventory(); // SPIGOT-2867
             enuminteractionresult = (event.useItemInHand() != Event.Result.ALLOW) ? EnumInteractionResult.SUCCESS : EnumInteractionResult.PASS;
         } else if (this.gamemode == EnumGamemode.SPECTATOR) {
-- 
2.18.0