Re: XPM via Lisp in the toolbar

[Richard Stallman]

    As long as the image is not _explicitly_ re-read from disk as in my
    example and as long as the image descriptor is not garbage collected,
    this should already be the case. Not even clearing the image cache (I
    mean the built-in image cache) would cause a second conversion,
    because the image descriptor contains all image data as a value of the
    :data attribute.

Are you sure that the same image is not likely to be read from disk
many times in an Emacs session?  I don't know for certain, but I would
have expected that to be common.