From 5722410f72d0698f6ad9ba668e2282ff0bac5043 Mon Sep 17 00:00:00 2001
From: James Miller <james@aatch.net>
Date: Thu, 18 Dec 2014 17:43:50 +1300
Subject: [PATCH] Fix logic error and add unreachable after returns

---
 src/librustc/middle/graph.rs     | 2 +-
 src/librustc_trans/trans/expr.rs | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/librustc/middle/graph.rs b/src/librustc/middle/graph.rs
index 3ba72801e2b..45bdf1c89cf 100644
--- a/src/librustc/middle/graph.rs
+++ b/src/librustc/middle/graph.rs
@@ -314,7 +314,7 @@ pub struct DepthFirstTraversal<'g, N:'g, E:'g> {
 impl<'g, N, E> Iterator<&'g N> for DepthFirstTraversal<'g, N, E> {
     fn next(&mut self) -> Option<&'g N> {
         while let Some(idx) = self.stack.pop() {
-            if self.visited.insert(idx.node_id()) {
+            if !self.visited.insert(idx.node_id()) {
                 continue;
             }
             self.graph.each_outgoing_edge(idx, |_, e| -> bool {
diff --git a/src/librustc_trans/trans/expr.rs b/src/librustc_trans/trans/expr.rs
index 6cefda59737..b185e8098e4 100644
--- a/src/librustc_trans/trans/expr.rs
+++ b/src/librustc_trans/trans/expr.rs
@@ -945,6 +945,10 @@ fn trans_rvalue_stmt_unadjusted<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
                 if let &Some(ref x) = ex {
                     bcx = trans_into(bcx, &**x, Ignore);
                 }
+                // Mark the end of the block as unreachable. Once we get to
+                // a return expression, there's no more we should be doing
+                // after this.
+                Unreachable(bcx);
                 bcx
             }
         }