patch, 4 partsgit.el: Check for existing buffers on revert.

Refuse to revert a file if it is modified in an existing buffer but not saved. On success, revert the buffers that contains the files that have been reverted.

Signed-off-by: Alexandre Julliard <julliard@winehq.org>
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 contrib/emacs/git.el |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

Alexandre Julliard <julliard@winehq.org> writes:

What's the point? What if I do want to have modified buffer and still revert the on-disk file? Why git-revert cares to the level of prohibiting this?

Besides, it's inconsistent with the rest of Emacs, I think, as in similar situations Emacs usually allows to either save the buffer(s), do not save the buffer(s) and continue, or abort operation (I suppose using (save-some-buffers) call, though I didn't check). See, for example, how (compile) behaves when some of buffers are not saved.

In fact I believe the way PCL-CVS handles this, and that was implemented in my earlier patch, is superior compared to this patch. An addition of save-some-buffers call won't hurt either, but IMHO is not very useful in the specific case of git-revert.

BTW, what definitely lacks (save-some-buffers) call is git-commit, as it silently commits on-disk state of a file when corresponding buffer is modified.

This part is indeed very handy.

-- Sergei Organov.

Sergei Organov <osv@javad.com> writes:

It's modeled on the vc-revert behavior, but yes, it could also prompt whether to discard changes; prompting to save doesn't make sense if you are about to throw away the changes. I think reverting the file on disk without changing the buffer is confusing: either you want to discard the changes, and you want to discard the buffer changes too, or you want to keep your changes, and reverting the file on disk doesn't make sense since the revert will be undone as soon as you save the buffer.

This could certainly be done, though it would have to be smarter than a simple (save-some-buffers), I find it very annoying when compile prompts to save a bunch of unrelated files.

Alexandre Julliard <julliard@winehq.org> writes:

Yes, and I think that prompting makes more sense at the time we try to actually revert buffer from disk. Besides this allows to eliminate the first check for modified buffers altogether.

And I'd put this (revert some buffers with prompt) into a separate function as I foresee a need for such a function when, say, git-checkout, or any other command that changes working files will be implemented.

I think that prompting is the best solution. It won't be a frequent situation, so prompting won't be annoying. Though this will differ both from VC and PCVS behavior.

BTW, there is another related issue: what to do with buffers for which their files disappear (are removed). AFAIK PCVS doesn't close such buffers, that according to the above logic is confusing as well.

[And so do I, but unlike git-commit, compile has no clue of what files are relevant (though it does lack a method to ignore buffers by, say, regexp of buffer name).]

I agree git-commit could be made smarter. Fortunately, save-some-buffers has /pred/ argument that allows for arbitrary filtering of buffers to be considered.

-- Sergei.

Sergei Organov wrote:

Please don't revert such buffers! More than once have I been saved from a blunder by the fact that Emacs still had a copy of the accidentally erase/overwritten file. The normal Emacs behaviour is to prompt upon editing whether to edit the buffer since the file has changed.

Thanks Tommy