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

[Phillip Lord]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Jorgen Schäfer <jorgen.schaefer@gmail.com>
>> Date: Sat, 12 Mar 2016 14:43:36 +0000
>> Cc: 21666@debbugs.gnu.org
>> 
>> I have been running 1b9d616 (emacs-25 branch) for the last three days and 
>> did not see any crashes, so this
>> problem seems to be specific to the master branch.
>
> Thanks, this is good to know.
>
> Phillip, I think this means the undo-related changes are actually
> exonerated, as they are present on emacs-25 as well, right?

Yes. My changes went in (just) before the branch. And, the fixes from
the GC problems you found went onto Emacs-25, then got merged to master.

Phil