Use an optional int for command redirection

Author: Camotoy

src/main/java/com/github/steveice10/mc/protocol/data/game/command/CommandNode.java

@@ -5,6 +5,8 @@
 import lombok.Data;
 import lombok.NonNull;
 
+import java.util.OptionalInt;
+
 @Data
 @AllArgsConstructor
 public class CommandNode {
@@ -24,9 +26,9 @@ public class CommandNode {
     private final @NonNull int[] childIndices;
 
     /**
-     * Redirect index, or -1 if none is set.
+     * Redirect index, or empty if none is set.
      */
-    private final int redirectIndex;
+    private final OptionalInt redirectIndex;
 
     /**
      * Name of the node, if type is LITERAL or ARGUMENT.

src/main/java/com/github/steveice10/mc/protocol/packet/ingame/clientbound/ClientboundCommandsPacket.java

@@ -12,6 +12,8 @@
 import lombok.NonNull;
 import lombok.With;
 
+import java.util.OptionalInt;
+
 @Data
 @With
 @AllArgsConstructor
@@ -42,9 +44,11 @@ public ClientboundCommandsPacket(ByteBuf in, MinecraftCodecHelper helper) {
                 children[j] = helper.readVarInt(in);
             }
 
-            int redirectIndex = 0;
+            OptionalInt redirectIndex;
             if ((flags & FLAG_REDIRECT) != 0) {
-                redirectIndex = helper.readVarInt(in);
+                redirectIndex = OptionalInt.of(helper.readVarInt(in));
+            } else {
+                redirectIndex = OptionalInt.empty();
             }
 
             String name = null;
@@ -163,7 +167,7 @@ public void serialize(ByteBuf out, MinecraftCodecHelper helper) {
                 flags |= FLAG_EXECUTABLE;
             }
 
-            if (node.getRedirectIndex() != 0) {
+            if (node.getRedirectIndex().isPresent()) {
                 flags |= FLAG_REDIRECT;
             }
 
@@ -178,8 +182,8 @@ public void serialize(ByteBuf out, MinecraftCodecHelper helper) {
                 helper.writeVarInt(out, childIndex);
             }
 
-            if (node.getRedirectIndex() != 0) {
-                helper.writeVarInt(out, node.getRedirectIndex());
+            if (node.getRedirectIndex().isPresent()) {
+                helper.writeVarInt(out, node.getRedirectIndex().getAsInt());
             }
 
             if (node.getType() == CommandType.LITERAL || node.getType() == CommandType.ARGUMENT) {

src/test/java/com/github/steveice10/mc/protocol/packet/ingame/clientbound/ClientboundCommandsPacketTest.java

@@ -9,6 +9,8 @@
 import com.github.steveice10.mc.protocol.packet.PacketTest;
 import org.junit.Before;
 
+import java.util.OptionalInt;
+
 public class ClientboundCommandsPacketTest extends PacketTest {
     @Before
     public void setup() {
@@ -18,7 +20,7 @@ public void setup() {
                                 CommandType.ROOT,
                                 true,
                                 new int[]{1, 2},
-                                0,
+                                OptionalInt.empty(),
                                 null,
                                 null,
                                 null,
@@ -28,7 +30,7 @@ public void setup() {
                                 CommandType.LITERAL,
                                 false,
                                 new int[]{3, 4},
-                                0,
+                                OptionalInt.empty(),
                                 "Literal",
                                 null,
                                 null,
@@ -38,7 +40,7 @@ public void setup() {
                                 CommandType.ARGUMENT,
                                 false,
                                 new int[0],
-                                3,
+                                OptionalInt.of(3),
                                 "Argument1",
                                 CommandParser.DOUBLE,
                                 new DoubleProperties(),
@@ -48,7 +50,7 @@ public void setup() {
                                 CommandType.ARGUMENT,
                                 false,
                                 new int[0],
-                                0,
+                                OptionalInt.empty(),
                                 "Argument2",
                                 CommandParser.DOUBLE,
                                 new DoubleProperties(0, 100),
@@ -58,7 +60,7 @@ public void setup() {
                                 CommandType.ARGUMENT,
                                 false,
                                 new int[0],
-                                0,
+                                OptionalInt.empty(),
                                 "Argument3",
                                 CommandParser.STRING,
                                 StringProperties.SINGLE_WORD,
@@ -68,7 +70,7 @@ public void setup() {
                                 CommandType.ARGUMENT,
                                 false,
                                 new int[0],
-                                0,
+                                OptionalInt.empty(),
                                 "Argument4",
                                 CommandParser.STRING,
                                 StringProperties.SINGLE_WORD,