Fix panic, tidy error

Author: tmandry

src/librustc/traits/select.rs

@@ -1174,18 +1174,6 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
         // resolving specializations.
         if candidates.len() > 1 {
             let mut i = 0;
-            //candidates.retain(|c| {
-            //    match c.candidate {
-            //        ParamCandidate(poly_trait_ref) => {
-            //            if poly_trait_ref == stack.obligation.predicate.map_bound(|x| x.trait_ref) {
-            //                debug!("Dropping candidate (== obligation): {:?}", c);
-            //                return false;
-            //            }
-            //        }
-            //        _ => {}
-            //    }
-            //    true
-            //});
             while i < candidates.len() {
                 let is_dup =
                     (0..candidates.len())

src/librustc/ty/mod.rs

@@ -2732,21 +2732,21 @@ fn param_env<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     // are any errors at that point, so after type checking you can be
     // sure that this will succeed without errors anyway.
 
-    let id = tcx.hir.as_local_node_id(def_id).unwrap();
-    debug!("param_env: handling def_id={:?}, id={:?}", def_id, id);
-
-    if let Some(hir::map::NodeItem(item)) = tcx.hir.find(id) {
-        debug!("  param_env: self node: {:?}", item.node);
-        if let hir::ItemTrait(..) = item.node {
-            debug!("    param_env: self is trait!");
-            let trait_ref = ty::TraitRef {
-                def_id: def_id,
-                substs: Substs::identity_for_item(tcx, def_id)
-            };
-            predicates.push(trait_ref.to_poly_trait_ref().to_predicate());
+    if let Some(id) = tcx.hir.as_local_node_id(def_id) {
+        debug!("param_env: handling def_id={:?}, id={:?}", def_id, id);
+        if let Some(hir::map::NodeItem(item)) = tcx.hir.find(id) {
+            debug!("  param_env: self node: {:?}", item.node);
+            if let hir::ItemTrait(..) = item.node {
+                debug!("    param_env: self is trait!");
+                let trait_ref = ty::TraitRef {
+                    def_id: def_id,
+                    substs: Substs::identity_for_item(tcx, def_id)
+                };
+                predicates.push(trait_ref.to_poly_trait_ref().to_predicate());
+            }
         }
+        debug!("  param_env predicates: {:?}", predicates);
     }
-    debug!("  param_env predicates: {:?}", predicates);
 
     let unnormalized_env = ty::ParamEnv::new(tcx.intern_predicates(&predicates),
                                              traits::Reveal::UserFacing);