Re: image cache

[Stefan Monnier <monnier@iro.umontreal.ca>]

>>>> BTW, does anyone know why each frame has an image cache (even though
>>>> there's really only one image cache per terminal)?
>>> A left-over from before multi-tty?
>> I don't think it's related.  The same "problem" was there in Emacs-22,
>> and Emacs-21.

> Note that fixing requires changing all the functions in image.c that
> require a frame argument, so that they use a terminal argument instead.
> Otherwise, if you associate image caches to terminals, you run into
> problems with terminals that have no frame (e.g. terminals created using
> x-open-connection), because you can't supply those image functions with
> a frame argument.

Yes, such a change will/would imply a whole bunch of changes, indeed.
I'm just wondering what is the reason for having chosen frames rather
than terminals when writing the code.  Seeing the current state of the
code, it appears that terminals would have been a much more natural
choice, so either I'm missing something, or something has changed which
makes it the natural choice now even tho it wasn't earlier, or the
author had some odd notion of "natural" (or maybe didn't even think
much about it and just chose it arbitrarily).


        Stefan