fix(compile): should not leak memory when there are top level empty text nodes

The change to prevent <span> elements being wrapped around empty text nodes caused these empty text nodes to have scopes and controllers attached, through jqLite.data() calls, which led to memory leaks and errors in IE8.
Now we exclude all but document nodes and elements from having jqLite.data() set both in the compiler and in ng-view.

Fixes: #1968 and #1876

4 files changed, 75 insertions, 4 deletions

diff --git a/src/ng/compile.js b/src/ng/compile.js
index 18adc2c9..2ed34f73 100644
--- a/src/ng/compile.js
+++ b/src/ng/compile.js
@@ -330,7 +330,14 @@ function $CompileProvider($provide) {
         var $linkNode = cloneConnectFn
           ? JQLitePrototype.clone.call($compileNodes) // IMPORTANT!!!
           : $compileNodes;
-        $linkNode.data('$scope', scope);
+
+        // Attach scope only to non-text nodes.
+        for(var i = 0, ii = $linkNode.length; i<ii; i++) {
+          var node = $linkNode[i];
+          if (node.nodeType == 1 /* element */ || node.nodeType == 9 /* document */) {
+            $linkNode.eq(i).data('$scope', scope);
+          }
+        }
         safeAddClass($linkNode, 'ng-scope');
         if (cloneConnectFn) cloneConnectFn($linkNode, scope);
         if (compositeLinkFn) compositeLinkFn(scope, $linkNode, $linkNode);
diff --git a/src/ng/directive/ngView.js b/src/ng/directive/ngView.js
index 2fd3a600..6e92c2d8 100644
--- a/src/ng/directive/ngView.js
+++ b/src/ng/directive/ngView.js
@@ -147,7 +147,7 @@ var ngViewDirective = ['$http', '$templateCache', '$route', '$anchorScroll', '$c
           if (current.controller) {
             locals.$scope = lastScope;
             controller = $controller(current.controller, locals);
-            element.contents().data('$ngControllerController', controller);
+            element.children().data('$ngControllerController', controller);
           }
 
           link(lastScope);
diff --git a/test/ng/compileSpec.js b/test/ng/compileSpec.js
index a7707cf9..3937f0e7 100644
--- a/test/ng/compileSpec.js
+++ b/test/ng/compileSpec.js
@@ -116,12 +116,17 @@ describe('$compile', function() {
 
   describe('compile phase', function() {
 
+    it('should attach scope to the document node when it is compiled explicitly', inject(function($document){
+      $compile($document)($rootScope);
+      expect($document.scope()).toBe($rootScope);
+    }));
+
     it('should wrap root text nodes in spans', inject(function($compile, $rootScope) {
       element = jqLite('<div>A&lt;a&gt;B&lt;/a&gt;C</div>');
       var text = element.contents();
       expect(text[0].nodeName).toEqual('#text');
       text = $compile(text)($rootScope);
-      expect(lowercase(text[0].nodeName)).toEqual('span');
+      expect(text[0].nodeName).toEqual('SPAN');
       expect(element.find('span').text()).toEqual('A<a>B</a>C');
     }));
 
@@ -137,6 +142,41 @@ describe('$compile', function() {
       expect(spans.text().indexOf('C')).toEqual(0);
     });
 
+    it('should not leak memory when there are top level empty text nodes', function() {
+      var calcCacheSize = function() {
+        var size = 0;
+        forEach(jqLite.cache, function(item, key) { size++; });
+        return size;
+      };
+
+      // We compile the contents of element (i.e. not element itself)
+      // Then delete these contents and check the cache has been reset to zero
+
+      // First with only elements at the top level
+      element = jqLite('<div><div></div></div>');
+      $compile(element.contents())($rootScope);
+      element.html('');
+      expect(calcCacheSize()).toEqual(0);
+
+      // Next with non-empty text nodes at the top level
+      // (in this case the compiler will wrap them in a <span>)
+      element = jqLite('<div>xxx</div>');
+      $compile(element.contents())($rootScope);
+      element.html('');
+      expect(calcCacheSize()).toEqual(0);
+
+      // Next with comment nodes at the top level
+      element = jqLite('<div><!-- comment --></div>');
+      $compile(element.contents())($rootScope);
+      element.html('');
+      expect(calcCacheSize()).toEqual(0);
+
+      // Finally with empty text nodes at the top level
+      element = jqLite('<div>   \n<div></div>   </div>');
+      $compile(element.contents())($rootScope);
+      element.html('');
+      expect(calcCacheSize()).toEqual(0);
+    });
 
     describe('multiple directives per element', function() {
       it('should allow multiple directives per element', inject(function($compile, $rootScope, log){
diff --git a/test/ng/directive/ngViewSpec.js b/test/ng/directive/ngViewSpec.js
index e90bb3bd..e781b98b 100644
--- a/test/ng/directive/ngViewSpec.js
+++ b/test/ng/directive/ngViewSpec.js
@@ -429,7 +429,7 @@ describe('ngView', function() {
       $rootScope.$digest();
       expect($rootScope.load).toHaveBeenCalledOnce();
     });
-  })
+  });
 
 
   it('should set $scope and $controllerController on the view', function() {
@@ -459,4 +459,28 @@ describe('ngView', function() {
       expect(div.controller()).toBe($route.current.scope.ctrl);
     });
   });
+
+  it('should not set $scope or $controllerController on top level text elements in the view', function() {
+    function MyCtrl($scope) {}
+
+    module(function($routeProvider) {
+      $routeProvider.when('/foo', {templateUrl: 'tpl.html', controller: MyCtrl});
+    });
+
+    inject(function($templateCache, $location, $rootScope, $route) {
+      $templateCache.put('tpl.html', '<div></div>  ');
+      $location.url('/foo');
+      $rootScope.$digest();
+
+      forEach(element.contents(), function(node) {
+        if ( node.nodeType == 3 ) {
+          expect(jqLite(node).scope()).not.toBe($route.current.scope);
+          expect(jqLite(node).controller()).not.toBeDefined();
+        } else {
+          expect(jqLite(node).scope()).toBe($route.current.scope);
+          expect(jqLite(node).controller()).toBeDefined();
+        }
+      });
+    });
+  });
 });