[slime-devel] Slime presentation marker bug

[Matthias Koeppe]

Hi Nathan,

On Thu, Sep 23, 2010 at 1:52 PM, Nathan Bird <nathan at acceleration.net> wrote:
>  I put a test case here that documents it: http://paste.lisp.org/+2GLO
>
> The issue is that when it starts a presentation it saves a marker, but
> then that marker gets moved when printing text and so when it ends the
> presentation the start and end markers are the same point, the one
> immediately after the text we are trying to present.
>
> I'm not sure where to go from here. I don't know how to get the old
> marker to stay in place any more than it is now. There is a comment:
>        ;; We use markers because text can also be inserted before this
> presentation.
>        ;; (Output arrives while we are writing presentations within
> REPL results.)
> Perhaps that is more relevant to printing with the target :repl-result
> vs target null?
>
> I tried changing the presentation start function (it's on the paste) to
> save the number if target is null and that looks like it is mostly
> working for me, can anyone else comment on the idea?

I don't think this is the right fix.

I believe this was broken in revision 1.33 of slime-presentations.el,
which replaced `slime-presentation-write'. I think the real bug is
that `slime-repl-emit' invokes `insert-before-markers'; I think it
should just call `insert' and then manually adjust the markers that
should be advanced. The old version of `slime-presentation-write' did
something like that.

Unfortunately I don't have the time to fix this.

Matthias
-- 
Matthias Koeppe -- http://www.math.ucdavis.edu/~mkoeppe