From a935481ae9052d42c39af1d71c8e8e64750c9e02 Mon Sep 17 00:00:00 2001
From: Nicholas Nethercote <nnethercote@mozilla.com>
Date: Fri, 21 Oct 2016 10:31:53 +1100
Subject: [PATCH] Avoid an unnecessary clone in `macro_parser::parse`.

This avoids ~800,000 allocations in html5ever.
---
 src/libsyntax/ext/tt/macro_parser.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/libsyntax/ext/tt/macro_parser.rs b/src/libsyntax/ext/tt/macro_parser.rs
index ef2e466a043..a664e115ce4 100644
--- a/src/libsyntax/ext/tt/macro_parser.rs
+++ b/src/libsyntax/ext/tt/macro_parser.rs
@@ -425,8 +425,8 @@ pub fn parse(sess: &ParseSess,
                         cur_eis.push(ei);
                     }
                     TokenTree::Token(_, ref t) => {
-                        let mut ei_t = ei.clone();
                         if token_name_eq(t,&tok) {
+                            let mut ei_t = ei.clone();
                             ei_t.idx += 1;
                             next_eis.push(ei_t);
                         }