Make sure arguments are preserved after redirects

See Mojang#138 (comment)

src/main/java/com/mojang/brigadier/CommandDispatcher.java

@@ -328,6 +328,7 @@ private ParseResults<S> parseNodes(final CommandNode<S> node, final StringReader
  reader.skip();
  if (child.getRedirect() != null) {
  final CommandContextBuilder<S> childContext = new CommandContextBuilder<>(this, source, child.getRedirect(), reader.getCursor());
+ childContext.withArguments(context.getArguments());
  final ParseResults<S> parse = parseNodes(child.getRedirect(), reader, childContext);
  context.withChild(parse.getContext());
  return new ParseResults<>(context, parse.getReader(), parse.getExceptions());

src/main/java/com/mojang/brigadier/context/CommandContextBuilder.java

@@ -50,6 +50,11 @@ public CommandContextBuilder<S> withArgument(final String name, final ParsedArgu
  return this;
  }
 
+ public CommandContextBuilder<S> withArguments(Map<String, ParsedArgument<S, ?>> arguments) {
+ this.arguments.putAll(arguments);
+ return this;
+ }
+
  public Map<String, ParsedArgument<S, ?>> getArguments() {
  return arguments;
  }

src/test/java/com/mojang/brigadier/CommandDispatcherTest.java

@@ -10,6 +10,7 @@
 import com.mojang.brigadier.context.CommandContext;
 import com.mojang.brigadier.context.CommandContextBuilder;
 import com.mojang.brigadier.exceptions.CommandSyntaxException;
+import com.mojang.brigadier.tree.ArgumentCommandNode;
 import com.mojang.brigadier.tree.LiteralCommandNode;
 import com.mojang.brigadier.tree.RootCommandNode;
 import org.hamcrest.CustomMatcher;
@@ -409,6 +410,22 @@ public void testRedirectModifierEmptyResult() throws CommandSyntaxException {
  assertThat(result, is(0)); // No commands executed, so result is 0
  }
 
+ @Test
+ public void testRedirectPreservesPreviousArguments() throws CommandSyntaxException {
+ final LiteralCommandNode<Object> ending = literal("ending")
+ .executes(context -> context.getArgument("number", int.class)).build();
+ final ArgumentCommandNode<Object, Integer> lowNumber = argument("number", integer(1, 10))
+ .then(ending).build();
+ final ArgumentCommandNode<Object, Integer> highNumber = argument("number", integer(11, 20))
+ .redirect(lowNumber).build();
+ subject.register(literal("base")
+ .then(literal("low").then(lowNumber))
+ .then(literal("high").then(highNumber)));
+
+ assertThat(subject.execute("base low 5 ending", source), is(5));
+ assertThat(subject.execute("base high 15 ending", source), is(15));
+ }
+
  @Test
  public void testExecuteOrphanedSubcommand() {
  subject.register(literal("foo").then(

src/test/java/com/mojang/brigadier/CommandSuggestionsTest.java

@@ -253,6 +253,26 @@ public void getCompletionSuggestions_redirect_lots() throws Exception {
  assertThat(result.getList(), equalTo(Lists.newArrayList(new Suggestion(StringRange.at(33), "loop"))));
  }
 
+ @Test
+ public void getCompletionSuggestions_redirectPreservesArguments() throws Exception {
+ subject.register(literal("command")
+ .then(
+ argument("first", integer())
+ .then(
+ argument("second", integer())
+ .suggests((context, builder) -> {
+ builder.suggest(String.valueOf(context.getLastChild().getArgument("first", int.class) + 1));
+ return builder.buildFuture();
+ })
+ )
+ ));
+ subject.register(literal("redirect").redirect(subject.getRoot()));
+
+ testSuggestions("command 1 ", 10, StringRange.at(10), "2");
+ testSuggestions("redirect command 1 ", 19, StringRange.at(19), "2");
+ testSuggestions("redirect redirect command 1 ", 28, StringRange.at(28), "2");
+ }
+
  @Test
  public void getCompletionSuggestions_execute_simulation() throws Exception {
  final LiteralCommandNode<Object> execute = subject.register(literal("execute"));

src/test/java/com/mojang/brigadier/context/CommandContextTest.java

@@ -14,6 +14,9 @@
 import org.mockito.Mock;
 import org.mockito.runners.MockitoJUnitRunner;
 
+import java.util.HashMap;
+import java.util.Map;
+
 import static org.hamcrest.Matchers.is;
 import static org.junit.Assert.assertThat;
 import static org.mockito.Mockito.mock;
@@ -51,6 +54,16 @@ public void testGetArgument() throws Exception {
  assertThat(context.getArgument("foo", int.class), is(123));
  }
 
+ @Test
+ public void testGetArguments() throws Exception {
+ Map<String, ParsedArgument<Object, ?>> arguments = new HashMap<>();
+ arguments.put("foo", new ParsedArgument<>(0, 1, 123));
+ arguments.put("bar", new ParsedArgument<>(0, 1, "123"));
+ final CommandContext<Object> context = builder.withArguments(arguments).build("123");
+ assertThat(context.getArgument("foo", int.class), is(123));
+ assertThat(context.getArgument("bar", String.class), is("123"));
+ }
+
  @Test
  public void testSource() throws Exception {
  assertThat(builder.build("").getSource(), is(source));