handle no favicon

README.md

@@ -15,7 +15,6 @@ At the moment this is not possible because of Firefox bug [1320585](https://bugz
 So this extension **tries** to get the favicon of the newly opened tab, and changes the color of the favicon to match that of the parent.
 
 But it will not work
-- on pages that don't have a favicon
 - on pages that don't allow content scripts (amo for example)
 - on pages that dynamically change the favicon
 - a lot of other cases

src/bg.js

@@ -7,7 +7,15 @@ var changeIcon = function(color, currentIcon) {
 	canvas.height = 16;
 	var ctx = canvas.getContext('2d');
 	var img = new Image();
-	img.src = currentIcon;
+
+	if (currentIcon && typeof(currentIcon) !== 'undefined' && currentIcon !== null && currentIcon !== 'undefined') {
+		console.log(currentIcon);
+		img.src = currentIcon;
+	} else {
+		img.src = 'data:image/x-icon;base64,AAABAAEAEBACAAEAAQCwAAAAFgAAACgAAAAQAAAAIAAAAAEAAQAAAAAAgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA////AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAD//wAA//8AAP//AAD//wAA//8AAP//AAD//wAA//8AAP//AAD//wAA//8AAP//AAD//wAA//8AAP//AAD//wAA';
+	}
+
+	console.log(img.src);
 	img.onload = function() {
 		ctx.drawImage(img, 0, 0);
 		ctx.fillStyle = color;
@@ -85,6 +93,7 @@ var updateAllColorsOnAllTabs = async () => {
 
 				if (tabs[i].status === 'complete') {
 					let t = getTabParent(tstTabs, tabs[i].id);
+
 					browser.tabs.executeScript(tabs[i].id, {
 						code: '(' + changeIcon.toString() + ')' +
 							'("' + generateRandomColor(t.parentIndex) + '", "' + t.faviconUrl + '")'