From ab11e6c4a35bfba5d5d47b8f02c7a09cdd441c8b Mon Sep 17 00:00:00 2001
From: Vladimir Dubrovin <3proxy@3proxy.ru>
Date: Tue, 2 Jun 2026 13:06:53 +0300
Subject: [PATCH] Fix deadlock in ftppr

---
 src/ftppr.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/ftppr.c b/src/ftppr.c
index 30c1739..f4a3f63 100644
--- a/src/ftppr.c
+++ b/src/ftppr.c
@@ -215,6 +215,11 @@ void * ftpprchild(struct clientparam* param) {
 			sasize = sizeof(param->sincr);
 			ss = param->srv->so._accept(param->sostate, clidatasock, (struct sockaddr *)&param->sincr, &sasize);
 			if (ss == INVALID_SOCKET) { RETURN (858);}
+#ifdef _WIN32
+			{ unsigned long ul = 1; ioctlsocket(ss, FIONBIO, &ul); }
+#else
+			fcntl(ss, F_SETFL, O_NONBLOCK | fcntl(ss, F_GETFL));
+#endif
 			param->srv->so._shutdown(param->sostate, clidatasock, SHUT_RDWR);
 			param->srv->so._closesocket(param->sostate, clidatasock);
 			clidatasock = ss;