Auto merge of #27827 - w00ns:for-loop-expn-issue-27639, r=alexcrichton

bors · bors · commit 29455557aa48 · 2015-08-15T14:50:13.000Z
Fixes #27639
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
@@ -385,16 +385,7 @@ pub fn expand_expr(e: P<ast::Expr>, fld: &mut MacroExpander) -> P<ast::Expr> {
             // expand <head>
             let head = fld.fold_expr(head);
 
-            // create an hygienic ident
-            let iter = {
-                let ident = fld.cx.ident_of("iter");
-                let new_ident = fresh_name(&ident);
-                let rename = (ident, new_ident);
-                let mut rename_list = vec![rename];
-                let mut rename_fld = IdentRenamer{ renames: &mut rename_list };
-
-                rename_fld.fold_ident(ident)
-            };
+            let iter = token::gensym_ident("iter");
 
             let pat_span = fld.new_span(pat.span);
             // `::std::option::Option::Some(<pat>) => <body>`
diff --git a/src/test/run-pass/issue-27639.rs b/src/test/run-pass/issue-27639.rs
@@ -0,0 +1,19 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// ignore-pretty
+
+fn main() {
+    const iter: i32 = 0;
+
+    for i in 1..10 {
+        println!("{}", i);
+    }
+}
