Subject: bug#1501: Emacs 22 loses undo buffer

From: "Emerick Rogul" <[email-masked]>
Date: Sun, 7 Dec 2008 07:36:01 -0500

No, I didn't enable any other major or minor modes before testing.  I
also ran emacs with -q --no-site-file.

Your theory about it being related to font-lock-mode appears to be
correct, however!  I started emacs, loaded the header file, disabled
font-lock-mode, and ran my test again and it behaved as expected
(i.e., it retained all of my undo records).  Is font-lock-mode using
up more records (or more record space) than expected?  I wonder if
it's also Windows-specific in some way?

On Sun, Dec 7, 2008 at 12:48 AM, Chong Yidong <[email-masked]> wrote:
> Actually, I went back and tried again.  Using the file you supplied, I
> had to do C-/ about 100 times before Emacs reached its undo-limit.  That
> implies 200 bytes per undo limit, which is about right.
>
> So there does seem to be something strange about the behavior you're
> seeing, where Emacs keeps only 20 or so undo records.
>
> Did you enable any other major or minor modes before testing this?
>
> Also, does turning font-lock-mode off change anything?
>