Re: M-g sometimes moves point one line up

[Stephen Berman <stephen.berman@gmx.net>]

On Sun, 24 Oct 2010 21:03:54 +0200 Stephen Berman <stephen.berman@gmx.net> wrote:

> On Sun, 24 Oct 2010 18:15:54 +0200 Lars Magne Ingebrigtsen <larsi@gnus.org> wrote:
>
>> Stephen Berman <stephen.berman@gmx.net> writes:
>>
>>> My .gnus.el does indeed have:
>>>
>>> (setq gnus-group-line-format "       %S%(%G%* (%y+%i)%)\n")
>>> (setq gnus-goto-next-group-when-activating nil)
>>
>> Yes, that should be fine.
>>
>> I've tried using this and `M-g'-ing here and there, and I'm unable to
>> get it to misbehave.
>
> Pity, but thanks for trying.  I'll chime in again if I notice anything
> that looks like a pattern.

I think I've found the cause of the problem.  When I start a Gnus
session and there are no unread articles in the current topic and its
parent topics, then it looks like this (I use the default value of
gnus-topic-line-format):

  [ Newsgroups -- 0 ]
    [ Gmane -- 0 ]
      [ Emacs -- 0 ]
        gmane.emacs.bugs (*+533)
        gmane.emacs.devel (*+1084)

If I put the cursor on column 0 of the gmane.emacs.bugs group line and
type `M-g', and there are two new articles, it now looks like this,
where `^' indicates point:

  [ Newsgroups -- 2 ]
    [ Gmane -- 2 ]
      [ Emacs -- 2 ]
        gmane.emacs.bugs^ (2+533)
        gmane.emacs.devel (*+1084)

If I put the cursor on column 0 of the gmane.emacs.devel group line and
type `M-g', and there are 19 new articles, it now looks like this, where
`^' indicates point, which is the same as above, instead of after
`gmane.emacs.devel':

  [ Newsgroups -- 21 ]
    [ Gmane -- 21 ]
      [ Emacs -- 21 ]
        gmane.emacs.bugs^ (2+533)
        gmane.emacs.devel (19+1084)

This misplacement is a result of the sexp (when beg (goto-char beg)) in
gnus-group-get-new-news-this-group: beg, which is point before invoking
`M-g', remains unchanged (after funcalling
gnus-group-update-group-function in gnus-group-update-group) when the
number of new articles does not increase the places of the numbers in
the topic lines, as is the case between 0 and 2, but not between 2 and
21 -- with the latter, point (beg) moves back by three characters,
putting it on the previous line.

I hope this is enough information for someone who knows the code better
than I do to come up with a fix.

Steve Berman