Fixed Image#{width,height} initialization to 0

src/Image.cc

@@ -149,6 +149,7 @@ Image::Image() {
   complete = false;
   filename = (char *) "";
   _surface = NULL;
+  width = height = 0;
 }
 
 /*

test/image.test.js

@@ -53,6 +53,24 @@ module.exports = {
     img.src = png + 's';
     assert.equal(img.src, png + 's');
 
+    beforeExit(function(){
+      assert.equal(1, n);
+    });
+  },
+  
+  'test Image#{width,height}': function(assert, beforeExit){
+    var img = new Image
+      , n = 0;
+    
+    assert.strictEqual(0, img.width);
+    assert.strictEqual(0, img.height);
+    img.onload = function(){
+      ++n;
+      assert.strictEqual(150, img.width);
+      assert.strictEqual(150, img.height);
+    };
+    img.src = png;
+
     beforeExit(function(){
       assert.equal(1, n);
     });