From 9e9c63c792bfa30df35a93b296faaee2dec53a70 Mon Sep 17 00:00:00 2001
From: Modderan <IrPgFKS0@users.noreply.github.com>
Date: Sun, 5 Jul 2026 07:42:51 -0700
Subject: [PATCH] Fix silent truncation of UDP datagrams over 1024 bytes

recvfrom() into a 1 KB buffer clips any larger datagram and the tail is
lost. A compressed position packet from a client with several moving
vehicles exceeds that, so those updates were silently dropped and the
remote vehicles stuttered/warped. Size the receive buffer to the UDP
maximum instead.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
---
 src/TNetwork.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/TNetwork.cpp b/src/TNetwork.cpp
index 3cf8b75c..203805e2 100644
--- a/src/TNetwork.cpp
+++ b/src/TNetwork.cpp
@@ -1356,7 +1356,10 @@ bool TNetwork::UDPSend(TClient& Client, std::vector<uint8_t> Data) {
 }
 
 std::vector<uint8_t> TNetwork::UDPRcvFromClient(boost::asio::ip::udp::endpoint& ClientEndpoint) {
-    std::array<char, 1024> Ret { };
+    // Sized to the UDP maximum: recvfrom() truncates a datagram that exceeds the buffer
+    // (the tail is silently lost). A compressed position packet from a client with several
+    // moving vehicles can exceed 1024 bytes, so such updates were silently dropped.
+    std::array<char, 65535> Ret { };
     boost::system::error_code ec;
     const auto Rcv = mUDPSock.receive_from(boost::asio::mutable_buffer(Ret.data(), Ret.size()), ClientEndpoint, 0, ec);
     if (ec) {