fix(wire): UnSmash only writes duration when it is not the default

THIS CHANGES THE BYTES SENT TO THE CLIENT (intentionally).

UnSmash::Serialize wrote the "duration != 3.0f" flag but guarded the
value with "builderID != 3.0f" (a typo), so the 32-bit duration was
always written, even after a 0 flag. The LEGO Universe 1.10.64 client
(GameMessage::UnSmash::Serialize/Deserialize @ 00dc0e80/00dc0f50,
default 3.0f @ 017e66b4) writes it only when
duration != 3.0f. The client read the flag and ignored the trailing 32
bits, so this removes 4 junk bytes from default UnSmash messages;
messages with a non-default duration are unchanged.

Uses WriteOptional/ReadOptional and adds Deserialize. Verified with
hand computed golden bits for every flag combination and round trips.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

dGame/dGameMessages/GameMessages.cpp

@@ -6450,10 +6450,14 @@ namespace GameMessages {
 	}
 
 	void UnSmash::Serialize(RakNet::BitStream& stream) const {
-		stream.Write(builderID != LWOOBJID_EMPTY);
+		// Both fields are optional with a default, like the client's GameMessage::UnSmash::Serialize.
-		if (builderID != LWOOBJID_EMPTY) stream.Write(builderID);
+		BitStreamUtils::WriteOptional(stream, builderID, LWOOBJID_EMPTY);
-		stream.Write(duration != 3.0f);
+		BitStreamUtils::WriteOptional(stream, duration, 3.0f);
-		if (builderID != 3.0f) stream.Write(duration);
+	}
+	bool UnSmash::Deserialize(RakNet::BitStream& stream) {
+		VALIDATE_READ(BitStreamUtils::ReadOptional(stream, builderID, LWOOBJID_EMPTY));
+		VALIDATE_READ(BitStreamUtils::ReadOptional(stream, duration, 3.0f));
+		return true;
 	}
 
 	void PlayBehaviorSound::Serialize(RakNet::BitStream& stream) const {

dGame/dGameMessages/GameMessages.h

@@ -890,6 +890,7 @@ namespace GameMessages {
 		UnSmash() : NetGameMsg(MessageType::Game::UN_SMASH) {}
 
 		void Serialize(RakNet::BitStream& stream) const override;
+		bool Deserialize(RakNet::BitStream& stream) override;
 
 		LWOOBJID builderID{ LWOOBJID_EMPTY };
 		float duration{ 3.0f };

tests/dGameTests/dGameMessagesTests/CMakeLists.txt

@@ -1,6 +1,7 @@
 SET(DGAMEMESSAGES_TESTS
 	"GameMessageTests.cpp"
 	"GameMsgSplitTests.cpp"
+	"UnSmashTests.cpp"
 	"LegacyGameMessageTests.cpp")
 
 # Get the folder name and prepend it to the files above

tests/dGameTests/dGameMessagesTests/UnSmashTests.cpp

@@ -0,0 +1,54 @@
+#include "GameMessages.h"
+#include "GameDependencies.h"
+#include "PacketTestUtils.h"
+
+#include <gtest/gtest.h>
+
+using namespace PacketTestUtils;
+
+// UnSmash layout from the 1.10.64 client (GameMessage::UnSmash::Serialize @ 00dc0e80):
+//   bit + i64 builderID, the i64 only if builderID != LWOOBJID_EMPTY
+//   bit + f32 duration,  the f32 only if duration != 3.0f
+// Expected bits below are hand computed (RakNet writes MSB first).
+namespace {
+	PacketBytes Payload(const GameMessages::UnSmash& msg) {
+		RakNet::BitStream bitStream;
+		msg.Serialize(bitStream);
+		return FromBitStream(bitStream);
+	}
+
+	GameMessages::UnSmash Make(LWOOBJID builderID, float duration) {
+		GameMessages::UnSmash msg;
+		msg.builderID = builderID;
+		msg.duration = duration;
+		return msg;
+	}
+}
+
+TEST(UnSmashTests, DefaultsWriteOnlyTwoFlagBits) {
+	// Before the fix, duration was written whenever builderID != 3.0f, i.e. always: 34 bits here.
+	EXPECT_PACKET_EQ(FromHex("00", 2), Payload(Make(LWOOBJID_EMPTY, 3.0f)));
+}
+
+TEST(UnSmashTests, GoldenBytes) {
+	EXPECT_PACKET_EQ(FromHex("84 03 83 02 82 01 81 00 80", 66), Payload(Make(0x0102030405060708LL, 3.0f)));
+	EXPECT_PACKET_EQ(FromHex("40 00 30 0f c0", 34), Payload(Make(LWOOBJID_EMPTY, 1.5f)));
+	EXPECT_PACKET_EQ(FromHex("84 03 83 02 82 01 81 00 c0 00 30 0f c0", 98), Payload(Make(0x0102030405060708LL, 1.5f)));
+}
+
+TEST(UnSmashTests, RoundTrip) {
+	for (const LWOOBJID builderID : { LWOOBJID_EMPTY, LWOOBJID{ 0x0102030405060708LL } }) {
+		for (const float duration : { 3.0f, 0.0f, 1.5f }) {
+			const auto msg = Make(builderID, duration);
+			RakNet::BitStream bitStream;
+			msg.Serialize(bitStream);
+			GameMessages::UnSmash read;
+			read.builderID = 42;
+			read.duration = 42.0f;
+			ASSERT_TRUE(read.Deserialize(bitStream));
+			EXPECT_EQ(read.builderID, builderID);
+			EXPECT_EQ(read.duration, duration);
+			EXPECT_EQ(bitStream.GetNumberOfUnreadBits(), 0);
+		}
+	}
+}