From a77331e725ebe396d73181cc3b83d7f2db1aae76 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Tue, 5 Dec 2023 13:51:03 +1100
Subject: [PATCH] AP_HAL: mark socket as not connected on EOF

this allows lua scripts to properly detect a closed TCP connection
---
 libraries/AP_HAL/utility/Socket.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libraries/AP_HAL/utility/Socket.cpp b/libraries/AP_HAL/utility/Socket.cpp
index 9b9698eb79..faab14d3d2 100644
--- a/libraries/AP_HAL/utility/Socket.cpp
+++ b/libraries/AP_HAL/utility/Socket.cpp
@@ -295,6 +295,10 @@ ssize_t SocketAPM::recv(void *buf, size_t size, uint32_t timeout_ms)
     ssize_t ret;
     ret = CALL_PREFIX(recvfrom)(fin, buf, size, MSG_DONTWAIT, (sockaddr *)&in_addr, &len);
     if (ret <= 0) {
+        if (!datagram && connected && ret == 0) {
+            // remote host has closed connection
+            connected = false;
+        }
         return ret;
     }
     if (fd_in != -1) {