SPIGOT-3143: Don't decrease item stack size if VehicleCreateEvent is cancelled

nms-patches/DispenserRegistry.patch

@@ -498,8 +498,9 @@
  
              entityboat.setType(this.c);
              entityboat.yaw = enumdirection.l();
-             world.addEntity(entityboat);
+-            world.addEntity(entityboat);
 -            itemstack.subtract(1);
++            if (!world.addEntity(entityboat)) itemstack.add(1); // CraftBukkit
 +            // itemstack.subtract(1); // CraftBukkit - handled during event processing
              return itemstack;
          }

nms-patches/ItemBoat.patch

@@ -14,3 +14,12 @@
                  Block block = world.getType(movingobjectposition.a()).getBlock();
                  boolean flag1 = block == Blocks.WATER || block == Blocks.FLOWING_WATER;
                  EntityBoat entityboat = new EntityBoat(world, movingobjectposition.pos.x, flag1 ? movingobjectposition.pos.y - 0.12D : movingobjectposition.pos.y, movingobjectposition.pos.z);
+@@ -66,7 +73,7 @@
+                     return new InteractionResultWrapper(EnumInteractionResult.FAIL, itemstack);
+                 } else {
+                     if (!world.isClientSide) {
+-                        world.addEntity(entityboat);
++                        if (!world.addEntity(entityboat)) return new InteractionResultWrapper(EnumInteractionResult.PASS, itemstack); // CraftBukkit
+                     }
+ 
+                     if (!entityhuman.abilities.canInstantlyBuild) {

nms-patches/ItemMinecart.patch

@@ -50,10 +50,20 @@
                  entityminecartabstract.setCustomName(itemstack.getName());
              }
  
-             world.addEntity(entityminecartabstract);
+-            world.addEntity(entityminecartabstract);
 -            itemstack.subtract(1);
++            if (!world.addEntity(entityminecartabstract)) itemstack.add(1);
 +            // itemstack.subtract(1); // CraftBukkit - handled during event processing
 +            // CraftBukkit end
              return itemstack;
          }
  
+@@ -83,7 +117,7 @@
+                     entityminecartabstract.setCustomName(itemstack.getName());
+                 }
+ 
+-                world.addEntity(entityminecartabstract);
++                if (!world.addEntity(entityminecartabstract)) return EnumInteractionResult.PASS; // CraftBukkit
+             }
+ 
+             itemstack.subtract(1);