From 8230851068dc6fdb84a1ea3aa2f993f196bfc02c Mon Sep 17 00:00:00 2001
From: Hugo Manrique <hugmanrique@gmail.com>
Date: Mon, 23 Jul 2018 14:22:26 +0200
Subject: [PATCH] Vanished players don't have rights


diff --git a/src/main/java/net/minecraft/server/Entity.java b/src/main/java/net/minecraft/server/Entity.java
index 6598b87eef..539273afbc 100644
--- a/src/main/java/net/minecraft/server/Entity.java
+++ b/src/main/java/net/minecraft/server/Entity.java
@@ -92,7 +92,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
     private static int entityCount;
     private final EntityTypes<?> g; public EntityTypes<?> getEntityType() { return g; } // Paper - OBFHELPER
     private int id;
-    public boolean j;
+    public boolean j; public boolean blocksEntitySpawning() { return j; } // Paper - OBFHELPER
     public final List<Entity> passengers;
     protected int k;
     private Entity vehicle;
diff --git a/src/main/java/net/minecraft/server/ItemBlock.java b/src/main/java/net/minecraft/server/ItemBlock.java
index f27d565e1e..49ad201c6e 100644
--- a/src/main/java/net/minecraft/server/ItemBlock.java
+++ b/src/main/java/net/minecraft/server/ItemBlock.java
@@ -70,7 +70,8 @@ public class ItemBlock extends Item {
 
     protected boolean b(BlockActionContext blockactioncontext, IBlockData iblockdata) {
         // CraftBukkit start - store default return
-        boolean defaultReturn = iblockdata.canPlace(blockactioncontext.getWorld(), blockactioncontext.getClickPosition()) && blockactioncontext.getWorld().a(iblockdata, blockactioncontext.getClickPosition());
+        final World world = blockactioncontext.getWorld(); // Paper
+        boolean defaultReturn = iblockdata.canPlace(world, blockactioncontext.getClickPosition()) && world.a(iblockdata, blockactioncontext.getClickPosition()) && world.checkNoVisiblePlayerCollisions(blockactioncontext.getEntity(), iblockdata.getCollisionShape(world, blockactioncontext.getClickPosition())); // Paper - Use our entity search
         org.bukkit.entity.Player player = (blockactioncontext.getEntity() instanceof EntityPlayer) ? (org.bukkit.entity.Player) blockactioncontext.getEntity().getBukkitEntity() : null;
 
         BlockCanBuildEvent event = new BlockCanBuildEvent(CraftBlock.at(blockactioncontext.getWorld(), blockactioncontext.getClickPosition()), player, CraftBlockData.fromData(iblockdata), defaultReturn);
diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
index 28fca165cd..1929e9d2ae 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -1521,6 +1521,37 @@ public abstract class World implements IEntityAccess, GeneratorAccess, IIBlockAc
         }
     }
 
+    // Paper start - Based on method below
+    /**
+     * @param entity causing the action ex. block placer
+     * @param voxelshape area to search within
+     * @return if there are no visible players colliding
+     */
+    public boolean checkNoVisiblePlayerCollisions(@Nullable Entity entity, VoxelShape voxelshape) {
+        if (voxelshape.isEmpty()) {
+            return true;
+        } else {
+            List list = this.getEntities((Entity) null, voxelshape.getBoundingBox());
+
+            for (int i = 0; i < list.size(); ++i) {
+                Entity entity1 = (Entity) list.get(i);
+
+                if (entity instanceof EntityPlayer && entity1 instanceof EntityPlayer) {
+                    if (!((EntityPlayer) entity).getBukkitEntity().canSee(((EntityPlayer) entity1).getBukkitEntity())) {
+                        continue;
+                    }
+                }
+
+                if (!entity1.dead && entity1.blocksEntitySpawning()) {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+    }
+    // Paper end
+
     public boolean a(@Nullable Entity entity, VoxelShape voxelshape) {
         if (voxelshape.isEmpty()) {
             return true;
diff --git a/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java b/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
index 2cfe8afe13..0a3a121cbc 100644
--- a/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
+++ b/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
@@ -1000,6 +1000,14 @@ public class CraftEventFactory {
         Projectile projectile = (Projectile) entity.getBukkitEntity();
         org.bukkit.entity.Entity collided = position.entity.getBukkitEntity();
         com.destroystokyo.paper.event.entity.ProjectileCollideEvent event = new com.destroystokyo.paper.event.entity.ProjectileCollideEvent(projectile, collided);
+
+        if (projectile.getShooter() instanceof Player && collided instanceof Player) {
+            if (!((Player) projectile.getShooter()).canSee((Player) collided)) {
+                event.setCancelled(true);
+                return event;
+            }
+        }
+
         Bukkit.getPluginManager().callEvent(event);
         return event;
     }
-- 
2.21.0