bug#66700: 30.0.50; Some history is missing with multiple eshell buffers

[Liu Hui]

Hi Eli,

Eli Zaretskii <eliz@gnu.org> 于2023年11月14日周二 20:32写道：

> > Since Eshell can append new history now, I think it makes sense to
> > change the default behavior from overwriting to appending, i.e., using
> > '(eshell-write-history nil t)' in eshell-exit-hook and
> > eshell-save-some-history. WDYT?
>
> IMO, this is too soon to change the default behavior in incompatible
> ways.  We need to wait for a while, perhaps at least one major
> release, before we do that.
>
> Thanks.

It is not an incompatible change at the user level. It is actually a
bug fix for people using multiple eshell sessions. For people using a
single eshell buffer, the history inside eshell, when reading back
from the file, is always same no matter how history is saved, and the
only difference is the content of history file.

As others have suggested, we could add an option to toggle the
behavior with appending new history as the default. It allows more
testing and users can easily revert back to old behavior. Do you think
it is acceptable?