From 62cedef3ee7021ce0fc476c2a96ebc9aa0e90515 Mon Sep 17 00:00:00 2001
From: Amanieu d'Antras <amanieu@gmail.com>
Date: Sun, 10 Apr 2016 15:25:28 +0100
Subject: [PATCH] Avoid undefined behavior from reading uninitialized data

---
 regex_macros/src/lib.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/regex_macros/src/lib.rs b/regex_macros/src/lib.rs
index 620f7b31b9..f6ff922f4e 100644
--- a/regex_macros/src/lib.rs
+++ b/regex_macros/src/lib.rs
@@ -309,7 +309,7 @@ fn exec<'t>(
 
         #[inline]
         fn contains(&self, pc: usize) -> bool {
-            let s = self.sparse[pc];
+            let s = unsafe { ::std::ptr::read_volatile(&self.sparse[pc]) };
             s < self.size && self.dense[s].pc == pc
         }