From 29c45c725b770a9045e5489ab4e712b3c2191f5d Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Sat, 22 Jul 2017 13:16:05 -0600
Subject: [PATCH] Return error when dup buf is not empty

---
 src/main.rs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/main.rs b/src/main.rs
index 6383797016..449e64a606 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -52,7 +52,11 @@ impl SchemeMut for PtyScheme {
         }
     }
 
-    fn dup(&mut self, id: usize, _buf: &[u8]) -> Result<usize> {
+    fn dup(&mut self, id: usize, buf: &[u8]) -> Result<usize> {
+        if ! buf.is_empty() {
+            return Err(Error::new(EINVAL));
+        }
+
         /* TODO CLOEXEC - Master cannot be cloned
         let master_opt = self.ptys.0.get(&id).map(|pipe| pipe.clone());
         if let Some(pipe) = master_opt {