Implement a row of simple optimizations to increase performance of Item constructors.

src/core/Base.js

@@ -70,7 +70,7 @@ this.Base = Base.inject(/** @lends Base# */{
 	 * @return {Boolean} {@true if the object is a plain object}
 	 */
 	_set: function(props) {
-		if (Base.isPlainObject(props)) {
+		if (props && Base.isPlainObject(props)) {
 			for (var key in props)
 				if (props.hasOwnProperty(key) && key in this)
 					this[key] = props[key];

src/item/Group.js

@@ -93,7 +93,7 @@ var Group = this.Group = Item.extend(/** @lends Group# */{
 		// Allow Group to have children and named children
 		this._children = [];
 		this._namedChildren = {};
-		if (!this._set(arg))
+		if (arg && !this._set(arg))
 			this.addChildren(Array.isArray(arg) ? arg : arguments);
 	},
 

src/item/Item.js

@@ -235,7 +235,8 @@ var Item = this.Item = Base.extend(Callback, {
 	 * });
 	 */
 	set: function(props) {
-		this._set(props);
+		if (props)
+			this._set(props);
 		return this;
 	},
 

src/item/PlacedSymbol.js

@@ -72,7 +72,7 @@ var PlacedSymbol = this.PlacedSymbol = PlacedItem.extend(/** @lends PlacedSymbol
 		this.base(arg1 !== undefined && Point.read(arguments, 1));
 		// If we can handle setting properties through object literal, we're all
 		// set. Otherwise we need to set symbol.
-		if (!this._set(arg0))
+		if (arg0 && !this._set(arg0))
 			this.setSymbol(arg0 instanceof Symbol ? arg0 : new Symbol(arg0));
 	},
 

src/path/CompoundPath.js

@@ -54,7 +54,7 @@ var CompoundPath = this.CompoundPath = PathItem.extend(/** @lends CompoundPath#
 		// CompoundPath has children and supports named children.
 		this._children = [];
 		this._namedChildren = {};
-		if (!this._set(arg))
+		if (arg && !this._set(arg))
 			this.addChildren(Array.isArray(arg) ? arg : arguments);
 	},
 

src/path/Path.Constructors.js

@@ -13,7 +13,11 @@
 Path.inject({ statics: new function() {
 
 	function createPath(args) {
-		return new Path().set(Base.getNamed(args));
+		var path = new Path(),
+			named = Base.getNamed(args);
+		if (named)
+			path._set(named);
+		return path;
 	}
 
 	function createRectangle(/* rect */) {

src/path/Path.js

@@ -86,7 +86,7 @@ var Path = this.Path = PathItem.extend(/** @lends Path# */{
 				? arguments
 				: null;
 		this.setSegments(segments || []);
-		if (!segments)
+		if (arg && !segments)
 			this._set(arg);
 	},
 

src/text/TextItem.js

@@ -41,7 +41,7 @@ var TextItem = this.TextItem = Item.extend(/** @lends TextItem# */{
 		this._paragraphStyle = ParagraphStyle.create(this);
 		// See if a point is passed, and if so, pass it on to base(). If not, it
 		// might be a properties object literal for #setPropeties() at the end.
-		var hasProperties = Base.isPlainObject(arg)
+		var hasProperties = arg && Base.isPlainObject(arg)
 				&& arg.x === undefined && arg.y === undefined;
 		this.base(hasProperties ? null : Point.read(arguments));
 		// No need to call setStyle(), since base() handles this already.
@@ -49,9 +49,8 @@ var TextItem = this.TextItem = Item.extend(/** @lends TextItem# */{
 		this.setParagraphStyle();
 		this._content = '';
 		this._lines = [];
-		if (hasProperties) {
+		if (hasProperties)
 			this._set(arg);
-		}
 	},
 
 	/**