pending-undo-list - should it not be buffer local?

pending-undo-list - should it not be buffer local?

[Lennart Borgman (gmail)]

Should not pending-undo-list be permanent buffer local?

Re: pending-undo-list - should it not be buffer local?

[Andreas Schwab]

"Lennart Borgman (gmail)" <lennart.borgman@gmail.com> writes:

> Should not pending-undo-list be permanent buffer local?

It is only used when undo is called immediately after undo, any other
command will break the chain.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: pending-undo-list - should it not be buffer local?

[Lennart Borgman (gmail)]

Andreas Schwab wrote:
> "Lennart Borgman (gmail)" <lennart.borgman@gmail.com> writes:
> 
>> Should not pending-undo-list be permanent buffer local?
> 
> It is only used when undo is called immediately after undo, any other
> command will break the chain.


Thanks, but why should it not be permanent buffer local then?

Re: pending-undo-list - should it not be buffer local?

[Andreas Schwab]

"Lennart Borgman (gmail)" <lennart.borgman@gmail.com> writes:

> Thanks, but why should it not be permanent buffer local then?

Why should it?

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: pending-undo-list - should it not be buffer local?

[Lennart Borgman (gmail)]

Andreas Schwab wrote:
> "Lennart Borgman (gmail)" <lennart.borgman@gmail.com> writes:
> 
>> Thanks, but why should it not be permanent buffer local then?
> 
> Why should it?


The reason I am asking is that I thought that there might be a chance 
that a kill-all-local-variables caused caused by the undo command might 
erase it. I am not at all sure that this is the case, but I am currently 
testing and at least with that change (permanent buffer local) I can not 
currently see the problems I saw before.

Can you see any way it can be erased by kill-all-local-variables before 
it should?

And my original question: Can you see any problems with making this 
variable permanent buffer local? (And are there perhaps other variables 
involved in undo that should also be permanent buffer local?)

Re: pending-undo-list - should it not be buffer local?

[Andreas Schwab]

"Lennart Borgman (gmail)" <lennart.borgman@gmail.com> writes:

> Can you see any way it can be erased by kill-all-local-variables before it
> should?

There is no way to interactively cause kill-all-local-variables to be
executed between two calls to undo without breaking the undo chain,
thereby causing pending-undo-list to be reset by the next undo (via
undo-start).

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: pending-undo-list - should it not be buffer local?

[Lennart Borgman (gmail)]

Andreas Schwab wrote:
> "Lennart Borgman (gmail)" <lennart.borgman@gmail.com> writes:
> 
>> Can you see any way it can be erased by kill-all-local-variables before it
>> should?
> 
> There is no way to interactively cause kill-all-local-variables to be
> executed between two calls to undo without breaking the undo chain,
> thereby causing pending-undo-list to be reset by the next undo (via
> undo-start).


Are you sure this true even if kill-all-local-variables are called from 
post-command-hook or from a timer? If so can you please explain to me why?

Re: pending-undo-list - should it not be buffer local?

[Andreas Schwab]

"Lennart Borgman (gmail)" <lennart.borgman@gmail.com> writes:

> Are you sure this true even if kill-all-local-variables are called from
> post-command-hook or from a timer? If so can you please explain to me why?

It doesn't matter anyway, since pending-undo-list isn't buffer-local in
the first place.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: pending-undo-list - should it not be buffer local?

[Lennart Borgman (gmail)]

Andreas Schwab wrote:
> "Lennart Borgman (gmail)" <lennart.borgman@gmail.com> writes:
> 
>> Are you sure this true even if kill-all-local-variables are called from
>> post-command-hook or from a timer? If so can you please explain to me why?
> 
> It doesn't matter anyway, since pending-undo-list isn't buffer-local in
> the first place.

Thanks, looks like a good argument here.

Re: pending-undo-list - should it not be buffer local?

[Richard Stallman]

    Should not pending-undo-list be permanent buffer local?

As far as I can see, it cannot ever make a difference.  That variable
is only used within a sequence of consecutive undo commands, and they
don't change the major mode.