Implement Item#isEmpty() for the various types.

And use it to tell #getBounds() when to ignore items.

src/item/Group.js

@@ -118,6 +118,10 @@ var Group = this.Group = Item.extend(/** @lends Group# */{
 		return this;
 	},
 
+	isEmpty: function() {
+		return this._children.length == 0;
+	},
+
 	draw: function(ctx, param) {
 		var clipItem = this._getClipItem();
 		if (clipItem) {

src/item/Item.js

@@ -665,7 +665,7 @@ function(name) {
 			y2 = x2;
 		for (var i = 0, l = children.length; i < l; i++) {
 			var child = children[i];
-			if (child._visible) {
+			if (child._visible && !child.isEmpty()) {
 				var rect = child._getCachedBounds(type, matrix, cacheItem);
 				x1 = Math.min(rect.x, x1);
 				y1 = Math.min(rect.y, y1);
@@ -676,6 +676,10 @@ function(name) {
 		return Rectangle.create(x1, y1, x2 - x1, y2 - y1);
 	},
 
+	isEmpty: function() {
+		return true;
+	},
+
 	setBounds: function(rect) {
 		rect = Rectangle.read(arguments);
 		var bounds = this.getBounds(),

src/item/PlacedSymbol.js

@@ -85,6 +85,10 @@ var PlacedSymbol = this.PlacedSymbol = PlacedItem.extend(/** @lends PlacedSymbol
 		symbol._instances[this._id] = this;
 	},
 
+	isEmpty: function() {
+		return this._symbol._definition.isEmpty();
+	},
+
 	clone: function() {
 		return this._clone(new PlacedSymbol(this.symbol, this._matrix.clone()));
 	},

src/item/Raster.js

@@ -109,6 +109,10 @@ var Raster = this.Raster = PlacedItem.extend(/** @lends Raster# */{
 		return this._size.height;
 	},
 
+	isEmpty: function() {
+		return this._size.width == 0 && this._size.height == 0;
+	},
+
 	/**
 	 * Pixels per inch of the raster at its current size.
 	 *

src/path/CompoundPath.js

@@ -85,6 +85,10 @@ var CompoundPath = this.CompoundPath = PathItem.extend(/** @lends CompoundPath#
 			this._children[i].smooth();
 	},
 
+	isEmpty: function() {
+		return this._children.length == 0;
+	},
+
 	draw: function(ctx, param) {
 		var children = this._children;
 		// Return early if the compound path doesn't have any children:

src/path/Path.js

@@ -229,6 +229,10 @@ var Path = this.Path = PathItem.extend(/** @lends Path# */{
 		// Do nothing for the same reason as above.
 	},
 
+	isEmpty: function() {
+		return this._segments.length == 0;
+	},
+
 	_apply: function(matrix) {
 		var coords = new Array(6);
 		for (var i = 0, l = this._segments.length; i < l; i++) {

src/text/TextItem.js

@@ -92,6 +92,10 @@ var TextItem = this.TextItem = Item.extend(/** @lends TextItem# */{
 		this._changed(Change.CONTENT);
 	},
 
+	isEmpty: function() {
+		return !!this._content;
+	},
+
 	/**
 	 * {@grouptitle Style Properties}
 	 *