We currently only use 16x16 favicons, but sometimes websites provide larger favicons, possibly all inside a single .ico file. We should take advantage of the larger favicons for desktop shortcuts when they are available. See widget/windows/nsDataObj.cpp nsDataObj :: GetFileContentsInternetShortcut And widget/windows/WinUtils.cpp AsyncFaviconDataReady::OnComplete For relevant code.

I'm interested in this bug, but I'm a bit green. After looking at the functions mentioned in Comment 1, what I've gathered is that nsDaatObj::GetFileContentsInternetShortcut() only retrieves the ICO file and its path, but is not responsible for any parsing. AsyncFaviconDataReady::OnComplete(), on the other hand, actually retrieves and draws image data. I would like some confirmation of this (as well as some pointing in the right direction) before I start working on this.

Yep we have a decoder for icons at: mozilla-central/image/decoders/nsICODecoder.h and .cpp I haven't looked at this code in a long time, and it might have changed since I last looked at it. But when I last seen it we always only picked one of the icons and had no handling to extract different icons from within that decoder.

We have the #-moz-resolution media fragment to extract specific sizes from an ICO but I'm not sure where that's done. Example: #-moz-resolution=32,32

Great, here are some ideas: http://dxr.mozilla.org/mozilla-central/search?q=moz-resolution&redirect=true