From 383f5bdfee5830c66cd273f5b4ee9be47d093b31 Mon Sep 17 00:00:00 2001
From: Torsten Scheck <torsten.scheck@gmx.de>
Date: Mon, 3 Jul 2017 18:04:37 +0200
Subject: [PATCH] Fix potential invalid memory reference.

---
 solutions/src/list.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/solutions/src/list.rs b/solutions/src/list.rs
index 3206982..c7ae6ad 100644
--- a/solutions/src/list.rs
+++ b/solutions/src/list.rs
@@ -53,6 +53,8 @@ impl<T> LinkedList<T> {
             if new_last.is_null() {
                 // The list is now empty.
                 self.first = new_last;
+            } else {
+                unsafe { (*new_last).next = ptr::null_mut() };
             }
             let last = unsafe { raw_into_box(last) } ;
             Some(last.data)
@@ -86,6 +88,8 @@ impl<T> LinkedList<T> {
             if new_first.is_null() {
                 // The list is now empty.
                 self.last = new_first;
+            } else {
+                unsafe { (*new_first).prev = ptr::null_mut() };
             }
             let first = unsafe { raw_into_box(first) } ;
             Some(first.data)
-- 
2.30.2