From 2eefd9bc857150f6c13d1a10ba12d7b2b84a180b Mon Sep 17 00:00:00 2001
From: Duncan Beevers <duncan@dweebd.com>
Date: Sun, 24 Aug 2014 03:32:14 -0500
Subject: [PATCH] Remove removable attrs with unspecified values

---
 src/htmlminifier.js | 7 +++++--
 tests/minifier.js   | 5 +++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/htmlminifier.js b/src/htmlminifier.js
index 0ec98b5..f98b455 100644
--- a/src/htmlminifier.js
+++ b/src/htmlminifier.js
@@ -209,7 +209,10 @@
       return trimWhitespace(attrValue);
     }
     else if (attrName === 'style') {
-      attrValue = trimWhitespace(attrValue).replace(/\s*;\s*$/, '');
+      attrValue = trimWhitespace(attrValue);
+      if (attrValue) {
+        attrValue = attrValue.replace(/\s*;\s*$/, '');
+      }
       if (options.minifyCSS) {
         return minifyCSS(attrValue, options.minifyCSS);
       }
@@ -278,7 +281,7 @@
       '?:down|up|over|move|out)|key(?:press|down|up)))$');
 
   function canDeleteEmptyAttribute(tag, attrName, attrValue) {
-    var isValueEmpty = /^(["'])?\s*\1$/.test(attrValue);
+    var isValueEmpty = !attrValue || /^(["'])?\s*\1$/.test(attrValue);
     if (isValueEmpty) {
       return (
         (tag === 'input' && attrName === 'value') ||
diff --git a/tests/minifier.js b/tests/minifier.js
index 93fa1f6..4079e95 100644
--- a/tests/minifier.js
+++ b/tests/minifier.js
@@ -260,6 +260,11 @@
 
     input = '<img src="" alt="">';
     equal(minify(input, { removeEmptyAttributes: true }), '<img src="" alt="">');
+
+    // preserve unrecognized attribute
+    // remove recognized attrs with unspecified values
+    input = '<div data-foo class id style title lang dir onfocus onblur onchange onclick ondblclick onmousedown onmouseup onmouseover onmousemove onmouseout onkeypress onkeydown onkeyup></div>';
+    equal(minify(input, { removeEmptyAttributes: true }), '<div data-foo></div>');
   });
 
   test('cleaning class/style attributes', function() {
-- 
2.34.1