bug#81229: 32.0.50; (vc-mode) log-edit-generate-changelog-from-diff fails on org-mode file check-in

Eli Zaretskii <[email protected]> writes:

>> I have been thinking about this for a while, and I am not convinced
>> about "does not have to move point".
>> 
>> end-of-defun in Elisp does not move point in one single case - at eob.
>
> That is exactly a case where it cannot move point.  How is your case
> different?

I am just describing the current existing behavior. (I do no like it).

>> IMHO, throwing a user error would be more useful.
>
> Why?  Signaling an error has various side effects, which are not
> necessarily useful.

> You are in effect inventing your own incompatible interpretation of
> the behavior when there's no next defun.  Why is this a good idea?

It is a common feature of many interactive commands to throw user-error
when they cannot do what they are supposed to do.

(defun end-of-defun (&optional arg interactive)
  "Move forward to next end of defun.

At the end of buffer, **next** end of defun is absent.
So, end-of-defun cannot perform what its own docstring describes.
Thus, it would make sense to signal user-error.
It would also benefit keyboard macros that make use of end-of-defun.
Without signaling error, those macros will inf-loop.

>> That said, end-of-defun-*function* is supposed to do something slightly
>> different -
>> "... the function can assume that point is at the beginning of the defun body.
>> It should move point to the first position after the defun."
>> I have fixed end-of-defun-function in Org to behave as the docstring
>> demands. (Similar for beginning-of-defun-function).
>> https://git.savannah.gnu.org/cgit/emacs/org-mode.git/commit/?id=7bd41df72
>
> Does this fix the issue reported in this bug?

Yes, I believe. But I did not test it as I do not have enough knowledge
of vc-mode to repeat the original reproducer.

-- 
Ihor Radchenko // yantar92,
Org mode maintainer,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
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