---

yaml
---
r: 124380
b: refs/heads/snap-stage3
c: 741bb1a
h: refs/heads/master
v: v3

Author: bgamari

[refs]

@@ -1,7 +1,7 @@
 ---
 refs/heads/master: 32cb44bfff3facbded5fd9cc74af3f02e81565a8
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
-refs/heads/snap-stage3: bdf5b6c3daa2797c704f1f1b335b1280b8d8fbdb
+refs/heads/snap-stage3: 741bb1a57e42c3a5e23ef9b01d4fc806b3fc56af
 refs/heads/try: dff46952ab5c4567d1b5b35bfbd8befc45cdd38e
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b

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

@@ -507,14 +507,20 @@ pub fn check_pat(pcx: &pat_ctxt, pat: &ast::Pat, expected: ty::t) {
             ty::ty_struct(cid, ref substs) => {
                 // Verify that the pattern named the right structure.
                 let item_did = tcx.def_map.borrow().get(&pat.id).def_id();
-                let struct_did =
-                    ty::ty_to_def_id(
-                        ty::lookup_item_type(tcx, item_did).ty).unwrap();
-                if struct_did != cid {
-                    span_err!(tcx.sess, pat.span, E0032,
-                        "`{}` does not name the structure `{}`",
-                        pprust::path_to_string(path),
-                        fcx.infcx().ty_to_string(expected));
+                match ty::ty_to_def_id(ty::lookup_item_type(tcx, item_did).ty) {
+                    Some(struct_did) if struct_did != cid => {
+                        span_err!(tcx.sess, path.span, E0032,
+                                  "`{}` does not name the structure `{}`",
+                                  pprust::path_to_string(path),
+                                  fcx.infcx().ty_to_string(expected));
+                    },
+                    Some(_) => {},
+                    None => {
+                        tcx.sess.span_bug(
+                            path.span,
+                            format!("This shouldn't happen: failed to lookup structure. \
+                                item_did = {}", item_did).as_slice())
+                    },
                 }
 
                 check_struct_pat(pcx, pat.id, pat.span, expected, path,