bug#1501: Emacs 22 loses undo buffer

[Stefan Kangas <stefan@marxist.se>]

tags 1501 wontfix
close 1501
thanks

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Stefan Kangas <stefan@marxist.se>
>> Date: Tue, 19 Oct 2021 18:01:43 -0700
>> Cc: Emerick Rogul <emerick@gmail.com>, 1501@debbugs.gnu.org,
>>  Chong Yidong <cyd@stupidchicken.com>
>>
>> +  /* Remove the `face' property to save space.  (Bug1501)  */
>> +  if (!NILP (string))
>> +    Fremove_list_of_text_properties (make_fixnum (0),
>> +				     make_fixnum (SCHARS (string)),
>> +				     CALLN (Flist, Qface),
>> +				     string);
>
> This modifies the text properties of STRING, which you don't own.
>
> Also, it will do unnecessary non-trivial processing when undo is
> turned off.
>
> I definitely think that with the enlarged undo-limit we should leave
> this obscure situation alone.  It isn't worth making such significant
> low-level changes due to such obscure problems, which are arguably
> cockpit errors.

OK, I'm therefore closing this bug as wontfix.

(Alternatively, we could just close it as "fixed" (with the doubling of
undo limits) but let's be a bit more explicit.)