---

yaml
---
r: 124381
b: refs/heads/snap-stage3
c: c6c1a22
h: refs/heads/master
i:
  124379: 8ad95d0
v: v3

Author: bgamari

[refs]

@@ -1,7 +1,7 @@
 ---
 refs/heads/master: 32cb44bfff3facbded5fd9cc74af3f02e81565a8
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
-refs/heads/snap-stage3: 741bb1a57e42c3a5e23ef9b01d4fc806b3fc56af
+refs/heads/snap-stage3: c6c1a22c563e0840f0efcccfe01a496114ac6ef0
 refs/heads/try: dff46952ab5c4567d1b5b35bfbd8befc45cdd38e
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b

branches/snap-stage3/src/librustc/middle/subst.rs

@@ -570,10 +570,22 @@ impl<'a> TypeFolder for SubstFolder<'a> {
         // the specialized routine
         // `middle::typeck::check::regionmanip::replace_late_regions_in_fn_sig()`.
         match r {
-            ty::ReEarlyBound(_, space, i, _) => {
+            ty::ReEarlyBound(_, space, i, region_name) => {
                 match self.substs.regions {
                     ErasedRegions => ty::ReStatic,
-                    NonerasedRegions(ref regions) => *regions.get(space, i),
+                    NonerasedRegions(ref regions) =>
+                        match regions.opt_get(space, i) {
+                            Some(t) => *t,
+                            None => {
+                                let span = self.span.unwrap_or(DUMMY_SP);
+                                self.tcx().sess.span_bug(
+                                    span,
+                                    format!("Type parameter out of range \
+                                     when substituting in region {} (root type={})",
+                                    region_name.as_str(),
+                                    self.root_ty.repr(self.tcx())).as_slice());
+                            }
+                        }
                 }
             }
             _ => r