---

yaml
---
r: 194665
b: refs/heads/master
c: 703308d
h: refs/heads/master
i:
  194663: 47edbc5
v: v3

Author: nikomatsakis

[refs]

@@ -1,5 +1,5 @@
 ---
-refs/heads/master: c59fe8bde2be55c46f627277e2cc37515fb7165e
+refs/heads/master: 703308db4a130191db4000dfbbfc92936c604b52
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
 refs/heads/snap-stage3: 552080181c58beef03493a110b4a38b20b6b5da5
 refs/heads/try: 961e0358e1a5c0faaef606e31e9965742c1643bf

trunk/src/librustc/middle/traits/fulfill.rs

@@ -164,6 +164,8 @@ impl<'tcx> FulfillmentContext<'tcx> {
         // debug output much nicer to read and so on.
         let obligation = infcx.resolve_type_vars_if_possible(&obligation);
 
+        assert!(!obligation.has_escaping_regions());
+
         if !self.duplicate_set.insert(obligation.predicate.clone()) {
             debug!("register_predicate({}) -- already seen, skip", obligation.repr(infcx.tcx));
             return;