bug#21666: Bug is indeed undo-list and GC related

[Eli Zaretskii]

> From: Jorgen Schäfer <jorgen.schaefer@gmail.com>
> Date: Wed, 09 Mar 2016 15:21:45 +0000
> Cc: 21666@debbugs.gnu.org
> 
> No, I can not. As mentioned, the problem occurs after a day or two of usage. 
> If you understand the problem
> better now that you know what prevents it, I am of course happy to run test 
> cases.

I cannot say I understand the problem better, sorry.

Are you running master or the emacs-25 branch?  If the former, can you
try the branch, please?  It is more urgent to have the branch bug-free
than the master, as we are in pretest for 25.1.

Also, what was date or the commit of the first build which exhibited
the problem?  Was that the one you reported in your original message
to the bug tracker?  Or did you experience these problems before that?

Thanks.