Merge branch 'pr/9'

verlok · Apr 27, 2014 · f3a0c42 · f3a0c42
2 parents 089963f + 2a07500
commit f3a0c42
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Showing 2 changed files with 23 additions and 2 deletions.
diff --git a/src/picturePolyfill.js b/src/picturePolyfill.js
@@ -208,12 +208,16 @@ var picturePolyfill = (function(w) {
 		 * @param attributes
 		 */
 		_setImg: function(pictureElement, attributes) {
-			var pictureAttributesToCopy, attributeName, attributeValue,
+			var pictureAttributesToCopy, attributeName, attributeValue, imgEl, imgSrc,
 				imageElements = pictureElement.getElementsByTagName('img');
 
 			// If image already exists, use it
 			if (imageElements.length) {
-				imageElements[0].setAttribute('src', attributes.src);
+				imgSrc = attributes.src;
+				imgEl = imageElements[0];
+				if (imgEl.getAttribute('src') !== imgSrc) {
+					imgEl.setAttribute('src', imgSrc);
+				}
 			}
 			// Else create the image
 			else {

diff --git a/test/picturePolyfill.qunit.js b/test/picturePolyfill.qunit.js
@@ -401,6 +401,23 @@ test("_setImg() should copy picture's width and height attributes to image", fun
 	strictEqual(images[0].getAttribute('height'), '69');
 });
 
+test("_setImg() should not load the same image twice", function() {
+	var testContainer, image;
+
+	$('body').append('<div id="testContainer"></div>');
+	testContainer = document.getElementById('testContainer');
+
+	picturePolyfill._setImg(testContainer, {src: 'http://placehold.it/1x1', alt: 'An image'});
+	testContainer = document.getElementById('testContainer');
+
+	image = testContainer.getElementsByTagName('img')[0];
+	this.spy(image, 'setAttribute');
+
+	picturePolyfill._setImg(testContainer, {src: 'http://placehold.it/1x1', alt: 'An image'});
+
+	ok(image.setAttribute.notCalled);
+})
+
 test("parse() is called at DOM ready", function() {
 	if (!document.createEvent) {
 		ok(true);