fix(angular.copy): support circular references

src/Angular.js

@@ -757,7 +757,7 @@ function isLeafNode (node) {
  </file>
  </example>
  */
-function copy(source, destination) {
+function copy(source, destination, stackSource, stackDest) {
   if (isWindow(source) || isScope(source)) {
     throw ngMinErr('cpws',
       "Can't copy! Making copies of Window or Scope instances is not supported.");
@@ -767,52 +767,82 @@ function copy(source, destination) {
     destination = source;
     if (source) {
       if (isArray(source)) {
-        destination = copy(source, []);
+        destination = copy(source, [], stackSource, stackDest);
       } else if (isDate(source)) {
         destination = new Date(source.getTime());
       } else if (isRegExp(source)) {
         destination = new RegExp(source.source);
       } else if (isObject(source)) {
-        destination = copy(source, {});
+        destination = copy(source, {}, stackSource, stackDest);
       }
     }
   } else {
     if (source === destination) throw ngMinErr('cpi',
       "Can't copy! Source and destination are identical.");
+
+    stackSource = stackSource || [];
+    stackDest = stackDest || [];
+
+    if (isObject(source)) {
+      var index = indexOf(stackSource, source);
+      if (index !== -1) return stackDest[index];
+
+      stackSource.push(source);
+      stackDest.push(destination);
+    }
+
+    var result;
     if (isArray(source)) {
       destination.length = 0;
       for ( var i = 0; i < source.length; i++) {
-        destination.push(copy(source[i]));
+        result = copy(source[i], null, stackSource, stackDest);
+        if (isObject(source[i])) {
+          stackSource.push(source[i]);
+          stackDest.push(result);
+        }
+        destination.push(result);
       }
     } else {
       var h = destination.$$hashKey;
       forEach(destination, function(value, key) {
         delete destination[key];
       });
       for ( var key in source) {
-        destination[key] = copy(source[key]);
+        result = copy(source[key], null, stackSource, stackDest);
+        if (isObject(source[key])) {
+          stackSource.push(source[key]);
+          stackDest.push(result);
+        }
+        destination[key] = result;
       }
       setHashKey(destination,h);
     }
+
   }
   return destination;
 }
 
 /**
- * Create a shallow copy of an object
+ * Creates a shallow copy of an object, an array or a primitive
  */
 function shallowCopy(src, dst) {
-  dst = dst || {};
+  if (isArray(src)) {
+    dst = dst || [];
+
+    for ( var i = 0; i < src.length; i++) {
+      dst[i] = src[i];
+    }
+  } else if (isObject(src)) {
+    dst = dst || {};
 
-  for(var key in src) {
-    // shallowCopy is only ever called by $compile nodeLinkFn, which has control over src
-    // so we don't need to worry about using our custom hasOwnProperty here
-    if (src.hasOwnProperty(key) && !(key.charAt(0) === '$' && key.charAt(1) === '$')) {
-      dst[key] = src[key];
+    for (var key in src) {
+      if (hasOwnProperty.call(src, key) && !(key.charAt(0) === '$' && key.charAt(1) === '$')) {
+        dst[key] = src[key];
+      }
     }
   }
 
-  return dst;
+  return dst || src;
 }
 
 

src/ng/directive/ngClass.js

@@ -78,7 +78,7 @@ function classDirective(name, selector) {
               updateClasses(oldClasses, newClasses);
             }
           }
-          oldVal = copy(newVal);
+          oldVal = shallowCopy(newVal);
         }
       }
     };

src/ng/directive/select.js

@@ -283,7 +283,7 @@ var selectDirective = ['$compile', '$parse', function($compile,   $parse) {
         // we need to work of an array, so we need to see if anything was inserted/removed
         scope.$watch(function selectMultipleWatch() {
           if (!equals(lastView, ctrl.$viewValue)) {
-            lastView = copy(ctrl.$viewValue);
+            lastView = shallowCopy(ctrl.$viewValue);
             ctrl.$render();
           }
         });

src/ng/http.js

@@ -111,9 +111,9 @@ function $HttpProvider() {
       common: {
         'Accept': 'application/json, text/plain, */*'
       },
-      post:   copy(CONTENT_TYPE_APPLICATION_JSON),
-      put:    copy(CONTENT_TYPE_APPLICATION_JSON),
-      patch:  copy(CONTENT_TYPE_APPLICATION_JSON)
+      post:   shallowCopy(CONTENT_TYPE_APPLICATION_JSON),
+      put:    shallowCopy(CONTENT_TYPE_APPLICATION_JSON),
+      patch:  shallowCopy(CONTENT_TYPE_APPLICATION_JSON)
     },
 
     xsrfCookieName: 'XSRF-TOKEN',
@@ -874,7 +874,7 @@ function $HttpProvider() {
           } else {
             // serving from cache
             if (isArray(cachedResp)) {
-              resolvePromise(cachedResp[1], cachedResp[0], copy(cachedResp[2]), cachedResp[3]);
+              resolvePromise(cachedResp[1], cachedResp[0], shallowCopy(cachedResp[2]), cachedResp[3]);
             } else {
               resolvePromise(cachedResp, 200, {}, 'OK');
             }

src/ng/parse.js

@@ -1072,7 +1072,7 @@ function $ParseProvider() {
               self.$$postDigestQueue.push(function () {
                 // create a copy if the value is defined and it is not a $sce value
                 if ((stable = isDefined(lastValue)) && !lastValue.$$unwrapTrustedValue) {
-                  lastValue = copy(lastValue);
+                  lastValue = copy(lastValue, null);
                 }
               });
             }

src/ng/rootScope.js

@@ -698,7 +698,7 @@ function $RootScopeProvider(){
                                && isNaN(value) && isNaN(last)))) {
                       dirty = true;
                       lastDirtyWatch = watch;
-                      watch.last = watch.eq ? copy(value) : value;
+                      watch.last = watch.eq ? copy(value, null) : value;
                       watch.fn(value, ((last === initWatchVal) ? value : last), current);
                       if (ttl < 5) {
                         logIdx = 4 - ttl;

src/ng/sce.js

@@ -737,7 +737,7 @@ function $SceProvider() {
         'document.  See http://docs.angularjs.org/api/ng.$sce for more information.');
     }
 
-    var sce = copy(SCE_CONTEXTS);
+    var sce = shallowCopy(SCE_CONTEXTS);
 
     /**
      * @ngdoc method

test/AngularSpec.js

@@ -146,6 +146,20 @@ describe('angular', function() {
       // make sure we retain the old key
       expect(hashKey(dst)).toEqual(h);
     });
+
+    it('should handle circular references when circularRefs is turned on', function () {
+      var a = {b: {a: null}, self: null, selfs: [null, null, [null]]};
+      a.b.a = a;
+      a.self = a;
+      a.selfs = [a, a.b, [a]];
+
+      var aCopy = copy(a, null);
+      expect(aCopy).toEqual(a);
+
+      expect(aCopy).not.toBe(a);
+      expect(aCopy).toBe(aCopy.self);
+      expect(aCopy.selfs[2]).not.toBe(a.selfs[2]);
+    });
   });
 
   describe("extend", function() {
@@ -218,6 +232,25 @@ describe('angular', function() {
       expect(clone.hello).toBeUndefined();
       expect(clone.goodbye).toBe("world");
     });
+
+    it('should handle arrays', function() {
+      var original = [{}, 1],
+          clone = [];
+
+      var aCopy = shallowCopy(original);
+      expect(aCopy).not.toBe(original);
+      expect(aCopy).toEqual(original);
+      expect(aCopy[0]).toBe(original[0]);
+
+      expect(shallowCopy(original, clone)).toBe(clone);
+      expect(clone).toEqual(original);
+    });
+
+    it('should handle primitives', function() {
+      expect(shallowCopy('test')).toBe('test');
+      expect(shallowCopy(3)).toBe(3);
+      expect(shallowCopy(true)).toBe(true);
+    });
   });
 
   describe('elementHTML', function() {