From 9b08cd8bd82eb70ae7d06a38f1f6d722cca2cc8d Mon Sep 17 00:00:00 2001
From: Steve Purcell <steve@sanityinc.com>
Date: Thu, 19 Sep 2013 13:29:28 +0100
Subject: [PATCH] fix($compile): merge attributes safely to avoid upsetting IE8

Merging an <input> with an <input> in IE8 will automatically break
because the "type" attribute may not be set automatically on in-document
elements. This change makes Angular replace only unchanged
attributes. Additionally, source and target attributes are only merged
by concatenation if their values differ, to avoid unexpected results
such as 'type="text text"'.

Closes #4029
---
 src/ng/compile.js      | 10 +++++++---
 test/ng/compileSpec.js | 16 ++++++++++++++++
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/src/ng/compile.js b/src/ng/compile.js
index d97aeaf6e557..fea91aa6fa3f 100644
--- a/src/ng/compile.js
+++ b/src/ng/compile.js
@@ -383,7 +383,10 @@ function $CompileProvider($provide) {
           if (writeAttr !== false) {
             if (value === null || value === undefined) {
               this.$$element.removeAttr(attrName);
-            } else {
+            } else if (value !== this.$$element.attr(attrName)) {
+              // Set new value only if it is not already there, avoiding
+              // issues with IE, where certain attributes cannot be set
+              // on in-document elements, e.g. 'type' on <input>
               this.$$element.attr(attrName, value);
             }
           }
@@ -1130,8 +1133,9 @@ function $CompileProvider($provide) {
       // reapply the old attributes to the new element
       forEach(dst, function(value, key) {
         if (key.charAt(0) != '$') {
-          if (src[key]) {
-            value += (key === 'style' ? ';' : ' ') + src[key];
+          var srcVal = src[key];
+          if (srcVal && srcVal !== value) {
+            value += (key === 'style' ? ';' : ' ') + srcVal;
           }
           dst.$set(key, value, true, srcAttr[key]);
         }
diff --git a/test/ng/compileSpec.js b/test/ng/compileSpec.js
index d26438783d70..7267d9638ca1 100755
--- a/test/ng/compileSpec.js
+++ b/test/ng/compileSpec.js
@@ -489,6 +489,14 @@ describe('$compile', function() {
               expect(element).toBe(attr.$$element);
             }
           }));
+          directive('replaceWithArbitraryAttribute', valueFn({
+            replace: true,
+            template: '<div data-foo="bar">With data-foo</div>',
+            compile: function(element, attr) {
+              attr.$set('compiled', 'COMPILED');
+              expect(element).toBe(attr.$$element);
+            }
+          }));
         }));
 
 
@@ -538,6 +546,14 @@ describe('$compile', function() {
           expect(div.attr('high-log')).toEqual('');
         }));
 
+        it('should preserve identical attributes when merging', inject(function($compile, $rootScope) {
+          element = $compile(
+            '<div><div replace-with-arbitrary-attribute data-foo="bar"/><div>')
+            ($rootScope);
+          var div = element.find('div');
+          expect(div.attr('data-foo')).toBe('bar');
+        }));
+
         it('should prevent multiple templates per element', inject(function($compile) {
           try {
             $compile('<div><span replace class="replace"></span></div>');