bug#17247: 24.4.50; end-of-defun bug in elisp

[Dmitry Gutov <dgutov@yandex.ru>]

On 20.05.2014 10:59, Andreas Röhler wrote:

> AFAIU the purpose is to make sure the beginning of current defun is
> fetched, not the previous one, i.e. protect for cases, point is at the
> beginning of defun.

Guess so. So with the proposed change, the point at the beginning of a 
defun doesn't "belong" to it anymore, but is considered "between defuns" 
instead. Seems to work fine, at least with the given Elisp example and a 
couple similar ones, with small differences.

> IMHO that end-of-defun section  is over-engineered, thus bug-sourcing.
>
> For example the common design-logic when taking numeric arguments: with
> positiv go forward, with negativ backward, resp. negate assumed direction.
>
> This seems broken internally by (funcall end-of-defun-function), which
> doesn't care for arguments.

The additional logic seems to be there to differentiate between two 
cases: we are inside a defun (beginning-of-defun followed by 
end-of-defun will move point forward), we are between defuns 
(beginning-of-defun followed by end-of-defun will move point backward), 
and handle them appropriately.