1 files changed, 10 insertions, 6 deletions
diff --git a/src/libstd/sync/mpsc/sync.rs b/src/libstd/sync/mpsc/sync.rs
index 3e2050799cc..733761671a0 100644
--- a/src/libstd/sync/mpsc/sync.rs
+++ b/src/libstd/sync/mpsc/sync.rs
@@ -343,8 +343,12 @@ impl<T> Packet<T> {
         mem::drop(guard);
 
         // only outside of the lock do we wake up the pending threads
-        pending_sender1.map(|t| t.signal());
-        pending_sender2.map(|t| t.signal());
+        if let Some(token) = pending_sender1 {
+            token.signal();
+        }
+        if let Some(token) = pending_sender2 {
+            token.signal();
+        }
     }
 
     // Prepares this shared packet for a channel clone, essentially just bumping
@@ -354,9 +358,7 @@ impl<T> Packet<T> {
 
         // See comments on Arc::clone() on why we do this (for `mem::forget`).
         if old_count > MAX_REFCOUNT {
-            unsafe {
-                abort();
-            }
+            abort();
         }
     }
 
@@ -410,7 +412,9 @@ impl<T> Packet<T> {
         while let Some(token) = queue.dequeue() {
             token.signal();
         }
-        waiter.map(|t| t.signal());
+        if let Some(token) = waiter {
+            token.signal();
+        }
     }
 }