From 5e91afd947b3d42bb583f61589756d8de15316f0 Mon Sep 17 00:00:00 2001
From: Roman Dvornov <rdvornov@gmail.com>
Date: Fri, 6 Jan 2017 15:51:09 +0500
Subject: [PATCH] add support for \0 IE hack (fixes #320)

---
 .../restructure/4-restructShorthand.js        |  9 +++---
 lib/compressor/restructure/6-restructBlock.js |  8 ++---
 test/fixture/compress/hack0.css               | 30 +++++++++++++++++++
 test/fixture/compress/hack0.min.css           |  1 +
 test/fixture/compress/hack9.css               |  2 +-
 5 files changed, 41 insertions(+), 9 deletions(-)
 create mode 100644 test/fixture/compress/hack0.css
 create mode 100644 test/fixture/compress/hack0.min.css

diff --git a/lib/compressor/restructure/4-restructShorthand.js b/lib/compressor/restructure/4-restructShorthand.js
index 4edae286..aa95e3cc 100644
--- a/lib/compressor/restructure/4-restructShorthand.js
+++ b/lib/compressor/restructure/4-restructShorthand.js
@@ -77,15 +77,16 @@ function TRBL(name) {
 
 TRBL.prototype.getValueSequence = function(value, count) {
     var values = [];
-    var iehack = false;
+    var iehack = '';
     var hasBadValues = value.sequence.some(function(child) {
         var special = false;
 
         switch (child.type) {
             case 'Identifier':
                 switch (child.name) {
+                    case '\\0':
                     case '\\9':
-                        iehack = true;
+                        iehack = child.name;
                         return;
 
                     case 'inherit':
@@ -141,7 +142,7 @@ TRBL.prototype.getValueSequence = function(value, count) {
         return false;
     }
 
-    if (typeof this.iehack === 'boolean' && this.iehack !== iehack) {
+    if (typeof this.iehack === 'string' && this.iehack !== iehack) {
         return false;
     }
 
@@ -301,7 +302,7 @@ TRBL.prototype.getValue = function() {
         result.push({ type: 'Space' }, {
             type: 'Identifier',
             info: {},
-            name: '\\9'
+            name: this.iehack
         });
     }
 
diff --git a/lib/compressor/restructure/6-restructBlock.js b/lib/compressor/restructure/6-restructBlock.js
index 7b3fd830..4933eed4 100644
--- a/lib/compressor/restructure/6-restructBlock.js
+++ b/lib/compressor/restructure/6-restructBlock.js
@@ -72,7 +72,7 @@ function getPropertyFingerprint(propertyName, declaration, fingerprints) {
 
     if (!fingerprint) {
         var vendorId = '';
-        var hack9 = '';
+        var iehack = '';
         var special = {};
 
         declaration.value.sequence.each(function walk(node) {
@@ -90,8 +90,8 @@ function getPropertyFingerprint(propertyName, declaration, fingerprints) {
                         vendorId = resolveKeyword(name).vendor;
                     }
 
-                    if (/\\9/.test(name)) {
-                        hack9 = name;
+                    if (/\\[09]/.test(name)) {
+                        iehack = RegExp.lastMatch;
                     }
 
                     if (realName === 'cursor') {
@@ -151,7 +151,7 @@ function getPropertyFingerprint(propertyName, declaration, fingerprints) {
             }
         });
 
-        fingerprint = '|' + Object.keys(special).sort() + '|' + hack9 + vendorId;
+        fingerprint = '|' + Object.keys(special).sort() + '|' + iehack + vendorId;
 
         fingerprints[declarationId] = fingerprint;
     }
diff --git a/test/fixture/compress/hack0.css b/test/fixture/compress/hack0.css
new file mode 100644
index 00000000..4c9da897
--- /dev/null
+++ b/test/fixture/compress/hack0.css
@@ -0,0 +1,30 @@
+/*
+  Declaration merge should be avoided when value has \0 
+*/
+
+.a {
+  border-top: 4px dashed;
+  border-top: 4px solid \0;
+}
+.a-2 {
+  border-top: 5px dashed;
+  border-top: 5px solid\0;
+}
+.b {
+  margin: 5px;
+  margin: 4px \0;
+  padding: 5px;
+  padding: 4px \0;
+  background: 10px 20px;
+  background: 20px 30px \0;
+}
+.c {
+  margin: 4px 0 0;
+  margin-top: 1px \0;
+}
+
+/* issue #320 */
+.selector {
+  width: 6ch;
+  width: 7ch\0;
+}
diff --git a/test/fixture/compress/hack0.min.css b/test/fixture/compress/hack0.min.css
new file mode 100644
index 00000000..b12ab20e
--- /dev/null
+++ b/test/fixture/compress/hack0.min.css
@@ -0,0 +1 @@
+.a{border-top:4px dashed;border-top:4px solid \0}.a-2{border-top:5px dashed;border-top:5px solid\0}.b{margin:5px;margin:4px \0;padding:5px;padding:4px \0;background:10px 20px;background:20px 30px \0}.c{margin:4px 0 0;margin-top:1px \0}.selector{width:6ch;width:7ch\0}
diff --git a/test/fixture/compress/hack9.css b/test/fixture/compress/hack9.css
index 927b2525..f5c81824 100644
--- a/test/fixture/compress/hack9.css
+++ b/test/fixture/compress/hack9.css
@@ -1,6 +1,6 @@
 /*
   Bootstrap and others uses \9 hack to target IE8-9
-  When value has \9 it should be avoid of merge
+  Declaration merge should be avoided when value has \9
 */
 
 .a {