Warning (undo): Buffer `*Buffer List*'

Warning (undo): Buffer `*Buffer List*'

[Tamas K Papp]

Hi,

After my Emacs has been running for a while, I get warnings like this:

----
Warning (undo): Buffer `*Buffer List*' undo info was 12075571 bytes long.
The undo info was discarded because it exceeded `undo-outer-limit'.

This is normal if you executed a command that made a huge change
to the buffer.  In that case, to prevent similar problems in the
future, set `undo-outer-limit' to a value that is large enough to
cover the maximum size of normal changes you expect a single
command to make, but not so large that it might exceed the
maximum memory allotted to Emacs.

If you did not execute any such command, the situation is
probably due to a bug and you should report it.

You can disable the popping up of this buffer by adding the entry
(undo discard-info) to the user option `warning-suppress-types',
which is defined in the `warnings' library.
----

I would like to figure out which, if any, of the Emacs programs I am
using is responsible for this, then report this as a bug, so I would
like to ask for some help with that --- is there a way I can monitor the
buffer to see what changes it?

buffer-undo-list in *Buffer List* looks like:

((nil tabulated-list-entry nil 3552 . 3553)
 (nil tabulated-list-entry nil 3547 . 3552)
 (nil tabulated-list-entry nil 3546 . 3547)
 (nil tabulated-list-entry nil 3535 . 3546)
 (nil tabulated-list-entry nil 3534 . 3535)
 (nil tabulated-list-entry nil 3533 . 3534)
 (nil tabulated-list-entry nil 3527 . 3533)
 (nil tabulated-list-entry nil 3519 . 3527)
...)

emacs-version: "24.3.1"

Best,

Tamas

Re: Warning (undo): Buffer `*Buffer List*'

[Michael Heerdegen]

Hi Tamas,

> Hi,
>
> After my Emacs has been running for a while, I get warnings like this:
>
> ----
> Warning (undo): Buffer `*Buffer List*' undo info was 12075571 bytes long.
> The undo info was discarded because it exceeded `undo-outer-limit'.

I wonder whether undo data in *Buffer List* is useful at all - I don't
think so.  ibuffer does (buffer-disable-undo) for its buffer list, and I
think the *Buffer List* should disable recording undo data as well.

With other words, I think this is just a bug, since *Buffer List* is a
read-only buffer.  Can you please submit a bug report (M-x
report-emacs-bug)?


Regards,

Michael.

Re: Warning (undo): Buffer `*Buffer List*'

[Tamas K Papp]

On Thu, Apr 25 2013, Michael Heerdegen wrote:

> Hi Tamas,
>
>> Hi,
>>
>> After my Emacs has been running for a while, I get warnings like this:
>>
>> ----
>> Warning (undo): Buffer `*Buffer List*' undo info was 12075571 bytes long.
>> The undo info was discarded because it exceeded `undo-outer-limit'.
>
> I wonder whether undo data in *Buffer List* is useful at all - I don't
> think so.  ibuffer does (buffer-disable-undo) for its buffer list, and I
> think the *Buffer List* should disable recording undo data as well.
>
> With other words, I think this is just a bug, since *Buffer List* is a
> read-only buffer.  Can you please submit a bug report (M-x
> report-emacs-bug)?

Thanks Michael, I have reported it as a bug.  In the meantime, how can I
work around this?  I would need to call (buffer-disable-undo) each time
*Buffer List* is created, but I could not find a hook for this.

Best,

Tamas

Re: Warning (undo): Buffer `*Buffer List*'

[Tassilo Horn]

Tamas K Papp <tkpapp@gmail.com> writes:

Hi Tamas,

>>> Warning (undo): Buffer `*Buffer List*' undo info was 12075571 bytes
>>> long.  The undo info was discarded because it exceeded
>>> `undo-outer-limit'.
>>
>> I wonder whether undo data in *Buffer List* is useful at all - I
>> don't think so.  ibuffer does (buffer-disable-undo) for its buffer
>> list, and I think the *Buffer List* should disable recording undo
>> data as well.
>>
>> With other words, I think this is just a bug, since *Buffer List* is
>> a read-only buffer.  Can you please submit a bug report (M-x
>> report-emacs-bug)?
>
> Thanks Michael, I have reported it as a bug.  In the meantime, how can
> I work around this?  I would need to call (buffer-disable-undo) each
> time *Buffer List* is created, but I could not find a hook for this.

I think this should do the trick:

  (add-hook 'Buffer-menu-mode-hook 'buffer-disable-undo)

Bye,
Tassilo

Re: Warning (undo): Buffer `*Buffer List*'

[Michael Heerdegen]

Tamas K Papp <tkpapp@gmail.com> writes:

> Thanks Michael, I have reported it as a bug.

Good, thanks!

>  In the meantime, how can I work around this?  I would need to call
> (buffer-disable-undo) each time *Buffer List* is created, but I could
> not find a hook for this.

As Tassilo suggested,

  (add-hook 'Buffer-menu-mode-hook 'buffer-disable-undo)

should be ok.


Regards,

Michael.