From 85f87b08ed7e91eec416bd0e27db090c38bd0e33 Mon Sep 17 00:00:00 2001
From: Jakub Pawlowicz <contact@jakubpawlowicz.com>
Date: Tue, 11 Apr 2017 12:12:15 +0200
Subject: [PATCH] Fixes #930 - regression in tidying selectors.

Why:

* `null` is not a safe argument to `replace` method as it's interpreted
  as a text pattern.
---
 History.md                              | 5 +++++
 lib/optimizer/level-1/tidy-rules.js     | 6 +++---
 test/optimizer/level-1/optimize-test.js | 8 ++++++++
 3 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/History.md b/History.md
index 28a0c7a9..cc5f4917 100644
--- a/History.md
+++ b/History.md
@@ -11,6 +11,11 @@
 * Fixed issue [#755](https://github.com/jakubpawlowicz/clean-css/issues/755) - adds custom handling of remote requests.
 * Fixed issue [#254](https://github.com/jakubpawlowicz/clean-css/issues/254) - adds `font` property optimizer.
 
+[4.0.12 / 2017-xx-xx](https://github.com/jakubpawlowicz/clean-css/compare/v4.0.11...4.0)
+==================
+
+* Fixed issue [#930](https://github.com/jakubpawlowicz/clean-css/issues/930) - regression in tidying selectors.
+
 [4.0.11 / 2017-04-04](https://github.com/jakubpawlowicz/clean-css/compare/v4.0.10...v4.0.11)
 ==================
 
diff --git a/lib/optimizer/level-1/tidy-rules.js b/lib/optimizer/level-1/tidy-rules.js
index 5aba2c7b..b47ed6b7 100644
--- a/lib/optimizer/level-1/tidy-rules.js
+++ b/lib/optimizer/level-1/tidy-rules.js
@@ -135,9 +135,9 @@ function removeWhitespace(value, format) {
     wasWhitespace = isWhitespace;
   }
 
-  return stripped
-    .join('')
-    .replace(withCaseAttribute ? CASE_RESTORE_PATTERN : null, '$1 $2]');
+  return withCaseAttribute ?
+    stripped.join('').replace(CASE_RESTORE_PATTERN, '$1 $2]') :
+    stripped.join('');
 }
 
 function removeQuotes(value) {
diff --git a/test/optimizer/level-1/optimize-test.js b/test/optimizer/level-1/optimize-test.js
index a8c8357f..89885cbd 100644
--- a/test/optimizer/level-1/optimize-test.js
+++ b/test/optimizer/level-1/optimize-test.js
@@ -144,6 +144,14 @@ vows.describe('level 1 optimizations')
       'missing semicolon and brace in the middle': [
         'body{color:red a{color:blue;}',
         ''
+      ],
+      'null as a selector name': [
+        '.null{color:red}',
+        '.null{color:red}'
+      ],
+      'null inside selector name': [
+        '.block--null{color:red}',
+        '.block--null{color:red}'
       ]
     }, { level: 1 })
   )
-- 
2.34.1