I was working to implement your proposed solution - it seemed most logical
to place overlay_prev_vec in the buffer struct, but placing the three
necessary properties( overlay_prev_vec, noverlays_prev,
prev_point_motion_hook ) in the structure caused the 'make' process to
return a segfault.  I'm going to look into this more in a few days, but do
you have any idea why this would be happening, or another implementation
strategy that wouldn't run into this problem?  I followed the instructions
about placing non-Lisp_Objects above the 'name' variable, so that is most
likely not the issue.

The last few lines produced by running make were:

LC_ALL=C `/bin/pwd`/temacs -batch -l loadup dump
Segmentation fault
make: *** [emacs] Error 139

Thanks,
Nathaniel Flath

On Sat, Oct 17, 2009 at 9:09 PM, Stefan Monnier <monnier@iro.umontreal.ca>wrote:

> > Any comments ont his?
>
> I haven't had much time to look into it, but I wonder: what happens when
> you switch buffer?
>
> I get the impression that your code currently will consider
> a buffer-switch as a kind of cursor movement to "very far away" (so it
> will run the leave&enter hooks).  I think it would be better to keep
> track of overlay_prev_vec as a per-buffer (or probably better
> per-window, tho that again introduces some questions when
> a window-buffer is changed) information.
>
>
>        Stefan
>