Paper/patches/api/0162-Support-cancellation-supression-of-EntityDismount-Ve.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Shane Freeder <theboyetronic@gmail.com>
Date: Sun, 18 Nov 2018 15:53:43 +0000
Subject: [PATCH] Support cancellation supression of EntityDismount/VehicleExit
 events"

Entities must be dismounted before teleportation in order to avoid
multiple issues in the server with regards to teleportation, shamefully,
too many plugins rely on the events firing, which means that not firing
these events caues more issues than it solves;

In order to counteract this, Entity dismount/exit vehicle events have
been modified to supress cancellation (and has a method to allow plugins
to check if this has been set), noting that cancellation will be silently
surpressed given that plugins are not expecting this event to not be cancellable.

This is a far from ideal scenario, however: given the current state of this
event and other alternatives causing issues elsewhere, I believe that
this is going to be the best soultion all around.

Improvements/suggestions welcome!

diff --git a/src/main/java/org/bukkit/event/entity/EntityDismountEvent.java b/src/main/java/org/bukkit/event/entity/EntityDismountEvent.java
index 00c3f50532392455070ae77ee4ad77cbf8d8827c..91188d77ff350aef20c3bde2bd27a8096825f337 100644
--- a/src/main/java/org/bukkit/event/entity/EntityDismountEvent.java
+++ b/src/main/java/org/bukkit/event/entity/EntityDismountEvent.java
@@ -13,10 +13,18 @@ public class EntityDismountEvent extends EntityEvent implements Cancellable {
     private static final HandlerList handlers = new HandlerList();
     private boolean cancelled;
     private final Entity dismounted;
+    private final boolean isCancellable; // Paper
 
     public EntityDismountEvent(@NotNull Entity what, @NotNull Entity dismounted) {
+        // Paper start
+        this(what, dismounted, true);
+    }
+
+    public EntityDismountEvent(@NotNull Entity what, @NotNull Entity dismounted, boolean isCancellable) {
+        // Paper end
         super(what);
         this.dismounted = dismounted;
+        this.isCancellable = isCancellable; // Paper
     }
 
     /**
@@ -36,9 +44,18 @@ public class EntityDismountEvent extends EntityEvent implements Cancellable {
 
     @Override
     public void setCancelled(boolean cancel) {
+        // Paper start
+        if (cancel && !this.isCancellable) {
+            return;
+        }
         this.cancelled = cancel;
     }
 
+    public boolean isCancellable() {
+        return this.isCancellable;
+        // Paper end
+    }
+
     @NotNull
     @Override
     public HandlerList getHandlers() {
diff --git a/src/main/java/org/bukkit/event/vehicle/VehicleExitEvent.java b/src/main/java/org/bukkit/event/vehicle/VehicleExitEvent.java
index 963b9ead4ca0426b2e95c5641b0e89317c48853d..39f6afd2f9cbcff6a74a91a21dcc3e29d2497dd8 100644
--- a/src/main/java/org/bukkit/event/vehicle/VehicleExitEvent.java
+++ b/src/main/java/org/bukkit/event/vehicle/VehicleExitEvent.java
@@ -13,10 +13,18 @@ public class VehicleExitEvent extends VehicleEvent implements Cancellable {
     private static final HandlerList handlers = new HandlerList();
     private boolean cancelled;
     private final LivingEntity exited;
+    private final boolean isCancellable; // Paper
 
-    public VehicleExitEvent(@NotNull final Vehicle vehicle, @NotNull final LivingEntity exited) {
+    public VehicleExitEvent(@NotNull final Vehicle vehicle, @NotNull final LivingEntity exited, boolean isCancellable) { // Paper
         super(vehicle);
         this.exited = exited;
+        // Paper start
+        this.isCancellable = isCancellable;
+    }
+
+    public VehicleExitEvent(@NotNull final Vehicle vehicle, @NotNull final LivingEntity exited) {
+        this(vehicle, exited, true);
+        // Paper end
     }
 
     /**
@@ -36,9 +44,18 @@ public class VehicleExitEvent extends VehicleEvent implements Cancellable {
 
     @Override
     public void setCancelled(boolean cancel) {
+        // Paper start
+        if (cancel && !isCancellable) {
+            return;
+        }
         this.cancelled = cancel;
     }
 
+    public boolean isCancellable() {
+        return isCancellable;
+        // Paper end
+    }
+
     @NotNull
     @Override
     public HandlerList getHandlers() {
diff --git a/src/main/java/org/spigotmc/event/entity/EntityDismountEvent.java b/src/main/java/org/spigotmc/event/entity/EntityDismountEvent.java
index be9560ffaa2d136ff1b5cd944baa678c1a938533..6533d1e0c5cb23e4a5e2831a56c5dbebe2d20f76 100644
--- a/src/main/java/org/spigotmc/event/entity/EntityDismountEvent.java
+++ b/src/main/java/org/spigotmc/event/entity/EntityDismountEvent.java
@@ -21,10 +21,19 @@ public class EntityDismountEvent extends EntityEvent implements Cancellable {
     private static final HandlerList handlers = new HandlerList();
     private boolean cancelled;
     private final Entity dismounted;
+    private final boolean isCancellable; // Paper
 
     public EntityDismountEvent(@NotNull Entity what, @NotNull Entity dismounted) {
-        super(what);
+        // Paper start
+        this(what, dismounted, true);
+    }
+
+
+    public EntityDismountEvent(@NotNull Entity what, @NotNull Entity dismounted, boolean isCancellable) {
+        // Paper end
+        super( what );
         this.dismounted = dismounted;
+        this.isCancellable = isCancellable; // Paper
     }
 
     @NotNull
@@ -39,9 +48,18 @@ public class EntityDismountEvent extends EntityEvent implements Cancellable {
 
     @Override
     public void setCancelled(boolean cancel) {
+        // Paper start
+        if (cancel && !isCancellable) {
+            return;
+        }
         this.cancelled = cancel;
     }
 
+    public boolean isCancellable() {
+        return isCancellable;
+        // Paper end
+    }
+
     @NotNull
     @Override
     public HandlerList getHandlers() {