From 954a712666ea3c10bfe1adcb665e159317b88964 Mon Sep 17 00:00:00 2001
From: dmiller <dmiller@e0a8ed71-7df4-0310-8962-fdc924857419>
Date: Sat, 11 Jul 2026 22:06:27 +0000
Subject: [PATCH] Save and restore errno in sigchld_handler()

waitpid() can set errno, which might hide an error from the main thread
when running the signal handler.
---
 ncat/ncat_listen.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/ncat/ncat_listen.c b/ncat/ncat_listen.c
index 67ec811e8..2064eaa42 100644
--- a/ncat/ncat_listen.c
+++ b/ncat/ncat_listen.c
@@ -173,8 +173,10 @@ static int get_conn_count(void)
 #ifndef WIN32
 static void sigchld_handler(int signum)
 {
+    int saved_errno = errno;
     while (waitpid(-1, NULL, WNOHANG) > 0)
         decrease_conn_count();
+    errno = saved_errno;
 }
 #endif