---

yaml
---
r: 193893
b: refs/heads/beta
c: bd2096c
h: refs/heads/master
i:
  193891: a62def6
v: v3

Author: nikomatsakis

[refs]

@@ -31,7 +31,7 @@ refs/heads/automation-fail: 1bf06495443584539b958873e04cc2f864ab10e4
 refs/heads/issue-18208-method-dispatch-3-quick-reject: 2009f85b9f99dedcec4404418eda9ddba90258a2
 refs/heads/batch: b7fd822592a4fb577552d93010c4a4e14f314346
 refs/heads/building: 126db549b038c84269a1e4fe46f051b2c15d6970
-refs/heads/beta: 99a508bc1795a7913ad790a3bf60f68dc782f282
+refs/heads/beta: bd2096c497580da263c20e8231666a995722ac29
 refs/heads/windistfix: 7608dbad651f02e837ed05eef3d74a6662a6e928
 refs/tags/1.0.0-alpha: e42bd6d93a1d3433c486200587f8f9e12590a4d7
 refs/heads/tmp: de8a23bbc3a7b9cbd7574b5b91a34af59bf030e6

branches/beta/src/librustc_trans/trans/meth.rs

@@ -842,13 +842,20 @@ fn emit_vtable_methods<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
                 return nullptr;
             }
 
-            let predicates =
-                monomorphize::apply_param_substs(tcx,
-                                                 &substs,
-                                                 &impl_method_type.predicates.predicates);
-            if !predicates_hold(ccx, predicates.into_vec()) {
-                debug!("emit_vtable_methods: predicates do not hold");
-                return nullptr;
+            // If this is a default method, it's possible that it
+            // relies on where clauses that do not hold for this
+            // particular set of type parameters. Note that this
+            // method could then never be called, so we do not want to
+            // try and trans it, in that case. Issue #23435.
+            if ty::provided_source(tcx, impl_method_def_id).is_some() {
+                let predicates =
+                    monomorphize::apply_param_substs(tcx,
+                                                     &substs,
+                                                     &impl_method_type.predicates.predicates);
+                if !predicates_hold(ccx, predicates.into_vec()) {
+                    debug!("emit_vtable_methods: predicates do not hold");
+                    return nullptr;
+                }
             }
 
             trans_fn_ref_with_substs(ccx,