From c45c345c6bd046383c973cb90dc025a1229ce086 Mon Sep 17 00:00:00 2001
From: Vitaly Puzrin <vitaly@rcdesign.ru>
Date: Sun, 26 Oct 2014 05:47:11 +0300
Subject: [PATCH] Perf: optimized html escape helper

---
 lib/common/utils.js | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/lib/common/utils.js b/lib/common/utils.js
index 97372f6..51d91f3 100644
--- a/lib/common/utils.js
+++ b/lib/common/utils.js
@@ -30,11 +30,15 @@ function assign(obj /*from1, from2, from3, ...*/) {
 }
 
 
+var ESCAPE_TEST_RE = /[<>"]/;
+
 function escapeHtml(str) {
-  if (str.indexOf('&') >= 0) { str = str.replace(/&/g, '&amp;'); }
-  if (str.indexOf('<') >= 0) { str = str.replace(/</g, '&lt;'); }
-  if (str.indexOf('>') >= 0) { str = str.replace(/>/g, '&gt;'); }
-  if (str.indexOf('"') >= 0) { str = str.replace(/"/g, '&quot;'); }
+  if (ESCAPE_TEST_RE.test(str)) {
+    if (str.indexOf('&') >= 0) { str = str.replace(/&/g, '&amp;'); }
+    if (str.indexOf('<') >= 0) { str = str.replace(/</g, '&lt;'); }
+    if (str.indexOf('>') >= 0) { str = str.replace(/>/g, '&gt;'); }
+    if (str.indexOf('"') >= 0) { str = str.replace(/"/g, '&quot;'); }
+  }
   return str;
 }