---

yaml
---
r: 89028
b: refs/heads/snap-stage3
c: a5d9762
h: refs/heads/master
v: v3

Author: pcwalton

[refs]

@@ -1,7 +1,7 @@
 ---
 refs/heads/master: deeca5d586bfaa4aa60246f671a8d611d38f6248
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
-refs/heads/snap-stage3: d9c87c7a2374dbdc5d5662af8548e95bbb616584
+refs/heads/snap-stage3: a5d976297285ad837e5c7e3a4ce5e9d01d3848c5
 refs/heads/try: b160761e35efcd1207112b3b782c06633cf441a8
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b

branches/snap-stage3/src/librustc/middle/typeck/check/method.rs

@@ -95,6 +95,7 @@ use middle::typeck::check::regionmanip::replace_bound_regions_in_fn_sig;
 use util::common::indenter;
 use util::ppaux::Repr;
 
+use std::cell::RefCell;
 use std::hashmap::HashSet;
 use std::result;
 use std::vec;
@@ -132,7 +133,7 @@ pub fn lookup(
         check_traits: CheckTraitsFlag,      // Whether we check traits only.
         autoderef_receiver: AutoderefReceiverFlag)
      -> Option<method_map_entry> {
-    let impl_dups = @mut HashSet::new();
+    let impl_dups = @RefCell::new(HashSet::new());
     let lcx = LookupContext {
         fcx: fcx,
         expr: expr,
@@ -174,7 +175,7 @@ pub struct LookupContext<'a> {
     callee_id: NodeId,
     m_name: ast::Name,
     supplied_tps: &'a [ty::t],
-    impl_dups: @mut HashSet<DefId>,
+    impl_dups: @RefCell<HashSet<DefId>>,
     inherent_candidates: @mut ~[Candidate],
     extension_candidates: @mut ~[Candidate],
     deref_args: check::DerefArgs,
@@ -540,8 +541,11 @@ impl<'a> LookupContext<'a> {
     fn push_candidates_from_impl(&self,
                                      candidates: &mut ~[Candidate],
                                      impl_info: &ty::Impl) {
-        if !self.impl_dups.insert(impl_info.did) {
-            return; // already visited
+        {
+            let mut impl_dups = self.impl_dups.borrow_mut();
+            if !impl_dups.get().insert(impl_info.did) {
+                return; // already visited
+            }
         }
         debug!("push_candidates_from_impl: {} {} {}",
                token::interner_get(self.m_name),