From e56eee50c8645f597f53a0c423b0851cfcf74ee7 Mon Sep 17 00:00:00 2001
From: practicalswift <practicalswift@users.noreply.github.com>
Date: Mon, 19 Mar 2018 09:21:45 +0100
Subject: [PATCH] Make sure we never pass a negative value to dup2(...)

---
 lightningd/subd.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lightningd/subd.c b/lightningd/subd.c
index 49ad2f47c..770a7acc5 100644
--- a/lightningd/subd.c
+++ b/lightningd/subd.c
@@ -30,6 +30,7 @@
 
 static bool move_fd(int from, int to)
 {
+	assert(from >= 0);
 	if (dup2(from, to) == -1)
 		return false;
 	close(from);