fix(jqLite): IE8 no longer replaces link text content with href mailto value

fixes angular#1949
IE bug: http://webbugtrack.blogspot.com.es/2008/07/bug-140-changing-mailto-links-error-in.html
Only happens when:
1. content has an @ but not ends with it. Regexp: /.*\S.*@.+/
2. href new value is like a URI or email (more or less) Regexp: /^((ftp|https?):\/\/|mailto:|.*@.+)/

To prevent IE from replacing the text content, the text nodes must be detached
before setting the href value and reattached afterwards.

Signed-off-by: Gonzalo Ruiz de Villa <gonzaloruizdevilla@gmail.com>

Author: gonzaloruizdevilla

src/jqLite.js

@@ -369,6 +369,23 @@ function getBooleanAttrName(element, name) {
   return booleanAttr && BOOLEAN_ELEMENTS[element.nodeName] && booleanAttr;
 }
 
+var IE_SPECIFIC_SET_ATTRIBUTE_CONTENT_PATTERN = /.*\S.*@.+/;
+var IE_SPECIFIC_SET_ATTRIBUTE_VALUE_PATTERN = /^((ftp|https?):\/\/|mailto:|.*@.+)/;
+function useIESpecificSetAttribute(element, name, value){
+  //when setting href value of a link with a text that contains a word with
+  //the pattern above will replace the content with the href value
+  //if the href value is URL like (pattern above)
+  var linkElement; 
+
+  return msie <= 8
+      && element.nodeName === "A"
+      && name === "href"
+      && IE_SPECIFIC_SET_ATTRIBUTE_VALUE_PATTERN.test(value)
+      && (linkElement = angular.element(element))
+      && linkElement.children().length === 0
+      && IE_SPECIFIC_SET_ATTRIBUTE_CONTENT_PATTERN.test(linkElement.text());
+}
+
 forEach({
   data: JQLiteData,
   inheritedData: JQLiteInheritedData,
@@ -415,7 +432,9 @@ forEach({
   },
 
   attr: function(element, name, value){
-    var lowercasedName = lowercase(name);
+    var textNodes,
+        lowercasedName = lowercase(name);
+
     if (BOOLEAN_ATTR[lowercasedName]) {
       if (isDefined(value)) {
         if (!!value) {
@@ -432,7 +451,21 @@ forEach({
                : undefined;
       }
     } else if (isDefined(value)) {
-      element.setAttribute(name, value);
+      // IE7 and IE8 in some conditions replaces links text content with href
+      // value. To prevent this, content must be detached and attached after setting the new
+      // href value
+      if (useIESpecificSetAttribute(element, lowercasedName, value)) {
+        textNodes = [];
+        while(element.firstChild){
+          textNodes.push(element.removeChild(element.firstChild));
+        }
+        element.setAttribute(name, value);
+        while (textNodes.length) {
+          element.appendChild(textNodes.shift());
+        }
+      } else {
+        element.setAttribute(name, value);
+      }
     } else if (element.getAttribute) {
       // the extra argument "2" is to get the right thing for a.href in IE, see jQuery code
       // some elements (e.g. Document) don't have get attribute, so return undefined

test/jqLiteSpec.js

@@ -406,6 +406,35 @@ describe('jqLite', function() {
       expect(elm.attr('readOnly')).toBeUndefined();
       expect(elm.attr('disabled')).toBeUndefined();
     });
+
+    it('should prevent IE for changing text content when setting attribute', function(){
+      var unchanged = true,
+          values = ["http:/","http://","https://","ftp://","mailto:","mailto","@","a@b"],
+          contents = [
+            "text with @arroba starting word",
+            "text with @ arroba starting word",
+            "text with @",
+            "text with (space at end) @ ",
+            "@ empty before",
+            " @ space before",
+            "- @ dash before",
+            "\n @ line feed before"
+          ];
+
+          function testValueWithTextContent(value, textContent){
+            var link = angular.element("<a>" + textContent + "</a>")
+                linkText = link.text();
+            link.attr("href", value);
+            unchanged = unchanged && (linkText == link.text());
+          }
+
+      forEach(values, function (value) {
+        forEach(contents, function (content) {
+          testValueWithTextContent(value, content);
+        });
+      });
+      expect(unchanged).toBe(true);
+    });
   });