From 3d8c4d4fe9358d23d9edd6ac016477f91f1de997 Mon Sep 17 00:00:00 2001
From: Oliver Schneider <git-spam-no-reply9815368754983@oli-obk.de>
Date: Thu, 25 Jan 2018 12:12:19 +0100
Subject: [PATCH] Don't read from zero sized fields

---
 src/librustc_mir/interpret/place.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/librustc_mir/interpret/place.rs b/src/librustc_mir/interpret/place.rs
index e82a252a95b3..4ca68068728d 100644
--- a/src/librustc_mir/interpret/place.rs
+++ b/src/librustc_mir/interpret/place.rs
@@ -123,6 +123,9 @@ impl<'a, 'mir, 'tcx, M: Machine<'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M> {
         }
         let field_index = field.index();
         let field = base_layout.field(self, field_index)?;
+        if field.size.bytes() == 0 {
+            return Ok(Some((Value::ByVal(PrimVal::Undef), field.ty)))
+        }
         let offset = base_layout.fields.offset(field_index);
         match base {
             // the field covers the entire type