bug#74352: 29.4; emerge-files with tramp + local file fails

[Michael Albinus via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Michael Albinus <michael.albinus@gmx.de> writes:

Hi Joerg,

>>> The point is, that emerge calls the 'diff' program for either the file
>>> itself (if local), or a local copy of the file (if remote). A consistent
>>> solution is therefore to set a local default directory, like
>>>
>>> --8<---------------cut here---------------start------------->8---
>>>     (setq default-directory temporary-file-directory)
>>> --8<---------------cut here---------------end--------------->8---
>>>
>>> instead of your change. Would you like to check?
>>
>> This works.
>>
>> But in the context of *emerge-make-diff-list* it is not very apparent why
>> *temporary-file-directory* is used. Maybe a comment should say that
>> *emerge-files-internal* copied the files there by *file-local-copy*.
>
> Sure, it doesn't hurt :-)
>
> My patch is rather a proof of concept. It could be improved in all directions.
>
>>> However, this won't be a complete solution. There are other places in
>>> emerge.el, where the temporary buffer for calling 'diff' must have a
>>> local default directory.
>>
>> Are you sure? I see only one usage of emerge-diff-program in emerge.el.
>
> There is also emerge-diff3-program, used in emerge-make-diff3-list.
>
> And there are also emerge-rcs-ci-program and emerge-rcs-co-program, used
> at different places. But I don't know whether they need special care.

I lost control. Are you still working on a patch?

Best regards, Michael.