Changed it so that if there's a NULL URL then we set the mLoadImageFailed

flag and don't try and load the broken image URL. Only on Windows for now
until Mac and Unix support the image icons

layout/generic/nsImageFrame.cpp

@@ -145,7 +145,12 @@ nsHTMLImageLoader::StartLoadImage(nsIPresContext* aPresContext,
   nsresult rv;
   nsAutoString src;
   if (mLoadImageFailed || (nsnull == mURLSpec)) {
+#ifdef _WIN32
+    mLoadImageFailed = PR_TRUE;
+    return NS_OK;
+#else
     src.Append(BROKEN_IMAGE_URL);
+#endif
   } else {
     nsAutoString baseURL;
     if (nsnull != mBaseHREF) {