Fix DFS bug

The DFS function uses an object as a key into another object. This
doesn't work, because the key gets stringified to "[object
Object]" and is therefore useless.

components/prism-core.js

@@ -16,6 +16,7 @@ var Prism = (function(){
 
 // Private helper vars
 var lang = /\blang(?:uage)?-(\w+)\b/i;
+var uniqueId = 0;
 
 var _ = _self.Prism = {
 	util: {
@@ -33,6 +34,13 @@ var _ = _self.Prism = {
 			return Object.prototype.toString.call(o).match(/\[object (\w+)\]/)[1];
 		},
 
+		objId: function (obj) {
+			if (!obj['__id']) {
+				Object.defineProperty(obj, '__id', { value: ++uniqueId });
+			}
+			return obj['__id'];
+		},
+
 		// Deep clone a language definition (e.g. to extend it)
 		clone: function (o) {
 			var type = _.util.type(o);
@@ -131,12 +139,12 @@ var _ = _self.Prism = {
 				if (o.hasOwnProperty(i)) {
 					callback.call(o, i, o[i], type || i);
 
-					if (_.util.type(o[i]) === 'Object' && !visited[o[i]]) {
-						visited[o[i]] = true;
+					if (_.util.type(o[i]) === 'Object' && !visited[_.util.objId(o[i])]) {
+						visited[_.util.objId(o[i])] = true;
 						_.languages.DFS(o[i], callback, null, visited);
 					}
-					else if (_.util.type(o[i]) === 'Array' && !visited[o[i]]) {
-						visited[o[i]] = true;
+					else if (_.util.type(o[i]) === 'Array' && !visited[_.util.objId(o[i])]) {
+						visited[_.util.objId(o[i])] = true;
 						_.languages.DFS(o[i], callback, i, visited);
 					}
 				}

prism.js

@@ -21,6 +21,7 @@ var Prism = (function(){
 
 // Private helper vars
 var lang = /\blang(?:uage)?-(\w+)\b/i;
+var uniqueId = 0;
 
 var _ = _self.Prism = {
 	util: {
@@ -38,6 +39,13 @@ var _ = _self.Prism = {
 			return Object.prototype.toString.call(o).match(/\[object (\w+)\]/)[1];
 		},
 
+		objId: function (obj) {
+			if (!obj['__id']) {
+				Object.defineProperty(obj, '__id', { value: ++uniqueId });
+			}
+			return obj['__id'];
+		},
+
 		// Deep clone a language definition (e.g. to extend it)
 		clone: function (o) {
 			var type = _.util.type(o);
@@ -136,12 +144,12 @@ var _ = _self.Prism = {
 				if (o.hasOwnProperty(i)) {
 					callback.call(o, i, o[i], type || i);
 
-					if (_.util.type(o[i]) === 'Object' && !visited[o[i]]) {
-						visited[o[i]] = true;
+					if (_.util.type(o[i]) === 'Object' && !visited[_.util.objId(o[i])]) {
+						visited[_.util.objId(o[i])] = true;
 						_.languages.DFS(o[i], callback, null, visited);
 					}
-					else if (_.util.type(o[i]) === 'Array' && !visited[o[i]]) {
-						visited[o[i]] = true;
+					else if (_.util.type(o[i]) === 'Array' && !visited[_.util.objId(o[i])]) {
+						visited[_.util.objId(o[i])] = true;
 						_.languages.DFS(o[i], callback, i, visited);
 					}
 				}