SPIGOT-4355: Improve cancelling VehicleEnterEvent

nms-patches/Entity.patch

@@ -425,7 +425,16 @@
              this.world.addEntity(entityitem);
              return entityitem;
          }
-@@ -1679,7 +1947,7 @@
+@@ -1658,7 +1926,7 @@
+             }
+ 
+             this.vehicle = entity;
+-            this.vehicle.o(this);
++            if (!this.vehicle.o(this)) this.vehicle = null; // CraftBukkit
+             return true;
+         }
+     }
+@@ -1679,15 +1947,33 @@
              Entity entity = this.vehicle;
  
              this.vehicle = null;
@@ -434,7 +443,9 @@
          }
  
      }
-@@ -1688,6 +1956,24 @@
+ 
+-    protected void o(Entity entity) {
++    protected boolean o(Entity entity) { // CraftBukkit
          if (entity.getVehicle() != this) {
              throw new IllegalStateException("Use x.startRiding(y), not y.addPassenger(x)");
          } else {
@@ -452,15 +463,18 @@
 +                CraftEntity craftn = (CraftEntity) entity.getBukkitEntity().getVehicle();
 +                Entity n = craftn == null ? null : craftn.getHandle();
 +                if (event.isCancelled() || n != orig) {
-+                    return;
++                    return false;
 +                }
 +            }
 +            // CraftBukkit end
              if (!this.world.isClientSide && entity instanceof EntityHuman && !(this.bO() instanceof EntityHuman)) {
                  this.passengers.add(0, entity);
              } else {
-@@ -1697,13 +1983,30 @@
+@@ -1695,15 +1981,33 @@
+             }
+ 
          }
++        return true; // CraftBukkit
      }
  
 -    protected void removePassenger(Entity entity) {
@@ -491,7 +505,7 @@
      }
  
      protected boolean q(Entity entity) {
-@@ -1800,6 +2103,13 @@
+@@ -1800,6 +2104,13 @@
      }
  
      public void setSwimming(boolean flag) {
@@ -505,7 +519,7 @@
          this.setFlag(4, flag);
      }
  
-@@ -1860,16 +2170,53 @@
+@@ -1860,16 +2171,53 @@
      }
  
      public void setAirTicks(int i) {
@@ -562,7 +576,7 @@
      }
  
      public void j(boolean flag) {
-@@ -2036,19 +2383,72 @@
+@@ -2036,19 +2384,72 @@
          if (!this.world.isClientSide && !this.dead) {
              this.world.methodProfiler.a("changeDimension");
              MinecraftServer minecraftserver = this.bK();
@@ -638,7 +652,7 @@
              BlockPosition blockposition;
  
              if (dimensionmanager == DimensionManager.THE_END) {
-@@ -2077,12 +2477,18 @@
+@@ -2077,12 +2478,18 @@
                  blockposition = new BlockPosition(this);
              }
  
@@ -658,7 +672,7 @@
                  if (dimensionmanager1 == DimensionManager.THE_END && dimensionmanager == DimensionManager.THE_END) {
                      BlockPosition blockposition1 = worldserver1.getHighestBlockYAt(HeightMap.Type.MOTION_BLOCKING_NO_LEAVES, worldserver1.getSpawn());
  
-@@ -2090,6 +2496,7 @@
+@@ -2090,6 +2497,7 @@
                  } else {
                      entity.setPositionRotation(blockposition, entity.yaw, entity.pitch);
                  }
@@ -666,7 +680,7 @@
  
                  boolean flag = entity.attachedToPlayer;
  
-@@ -2097,13 +2504,21 @@
+@@ -2097,13 +2505,21 @@
                  worldserver1.addEntity(entity);
                  entity.attachedToPlayer = flag;
                  worldserver1.entityJoinedWorld(entity, false);
@@ -689,7 +703,7 @@
              return entity;
          } else {
              return null;
-@@ -2243,7 +2658,26 @@
+@@ -2243,7 +2659,26 @@
      }
  
      public void a(AxisAlignedBB axisalignedbb) {