From e92bf84a535b77c65127fadc2b82d762cff8ab66 Mon Sep 17 00:00:00 2001
From: Georg Brandl <georg@python.org>
Date: Sat, 22 Aug 2015 08:57:05 +0200
Subject: [PATCH] ptr_arg: fix panic when pattern type is not in tcx

---
 src/ptr_arg.rs | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/src/ptr_arg.rs b/src/ptr_arg.rs
index f0a0592f5e2..2d09fcbcca9 100644
--- a/src/ptr_arg.rs
+++ b/src/ptr_arg.rs
@@ -45,20 +45,18 @@ impl LintPass for PtrArg {
 
 fn check_fn(cx: &Context, decl: &FnDecl) {
     for arg in &decl.inputs {
-        if arg.ty.node == TyInfer {  // "self" arguments
-            continue;
-        }
-        let ref sty = cx.tcx.pat_ty(&*arg.pat).sty;
-        if let &ty::TyRef(_, ty::TypeAndMut { ty, mutbl: MutImmutable }) = sty {
-            if match_type(cx, ty, &VEC_PATH) {
-                span_lint(cx, PTR_ARG, arg.ty.span,
-                          "writing `&Vec<_>` instead of `&[_]` involves one more reference \
-                           and cannot be used with non-Vec-based slices. Consider changing \
-                           the type to `&[...]`");
-            } else if match_type(cx, ty, &STRING_PATH) {
-                span_lint(cx, PTR_ARG, arg.ty.span,
-                          "writing `&String` instead of `&str` involves a new object \
-                           where a slice will do. Consider changing the type to `&str`");
+        if let Some(pat_ty) = cx.tcx.pat_ty_opt(&*arg.pat) {
+            if let ty::TyRef(_, ty::TypeAndMut { ty, mutbl: MutImmutable }) = pat_ty.sty {
+                if match_type(cx, ty, &VEC_PATH) {
+                    span_lint(cx, PTR_ARG, arg.ty.span,
+                              "writing `&Vec<_>` instead of `&[_]` involves one more reference \
+                               and cannot be used with non-Vec-based slices. Consider changing \
+                               the type to `&[...]`");
+                } else if match_type(cx, ty, &STRING_PATH) {
+                    span_lint(cx, PTR_ARG, arg.ty.span,
+                              "writing `&String` instead of `&str` involves a new object \
+                               where a slice will do. Consider changing the type to `&str`");
+                }
             }
         }
     }