SPIGOT-1181: Ensure Minecart command updates visually

nms-patches/EntityMinecartCommandBlock.patch

@@ -1,7 +1,11 @@
 --- a/net/minecraft/server/EntityMinecartCommandBlock.java
 +++ b/net/minecraft/server/EntityMinecartCommandBlock.java
-@@ -7,6 +7,9 @@
+@@ -4,9 +4,12 @@
-     private static final DataWatcherObject<String> a = DataWatcher.a(EntityMinecartCommandBlock.class, DataWatcherRegistry.d);
+ 
+ public class EntityMinecartCommandBlock extends EntityMinecartAbstract {
+ 
+-    private static final DataWatcherObject<String> a = DataWatcher.a(EntityMinecartCommandBlock.class, DataWatcherRegistry.d);
++    public static final DataWatcherObject<String> a = DataWatcher.a(EntityMinecartCommandBlock.class, DataWatcherRegistry.d); // PAIL: private -> public
      private static final DataWatcherObject<IChatBaseComponent> b = DataWatcher.a(EntityMinecartCommandBlock.class, DataWatcherRegistry.e);
      private final CommandBlockListenerAbstract c = new CommandBlockListenerAbstract() {
 +        {

src/main/java/org/bukkit/craftbukkit/entity/CraftMinecartCommand.java

@@ -22,19 +22,25 @@ public class CraftMinecartCommand extends CraftMinecart implements CommandMineca
         super(server, entity);
     }
 
+    @Override
+    public EntityMinecartCommandBlock getHandle() {
+        return (EntityMinecartCommandBlock) entity;
+    }
+
     @Override
     public String getCommand() {
-        return ((EntityMinecartCommandBlock) getHandle()).getCommandBlock().getCommand();
+        return getHandle().getCommandBlock().getCommand();
     }
 
     @Override
     public void setCommand(String command) {
-        ((EntityMinecartCommandBlock) getHandle()).getCommandBlock().setCommand(command != null ? command : "");
+        getHandle().getCommandBlock().setCommand(command != null ? command : "");
+        getHandle().getDataWatcher().set(EntityMinecartCommandBlock.a, getHandle().getCommandBlock().getCommand()); // PAIL: rename
     }
 
     @Override
     public void setName(String name) {
-        ((EntityMinecartCommandBlock) getHandle()).getCommandBlock().setName(name != null ? name : "@");
+        getHandle().getCommandBlock().setName(name != null ? name : "@");
     }
 
     @Override
@@ -52,7 +58,7 @@ public class CraftMinecartCommand extends CraftMinecart implements CommandMineca
 
     @Override
     public String getName() {
-        return ((EntityMinecartCommandBlock) getHandle()).getCommandBlock().getName();
+        return getHandle().getCommandBlock().getName();
     }
 
     @Override