Re: Summary Buffer cursor jumps to the center and no proper status update

[Katsumi Yamaoka <yamaoka@jpl.org>]

>>>>> Yuan MEI wrote:
> Hi,
>     This really works for me, why don't you put it into CVS trunk?
> Thank you

Why I haven't installed the change into Gnus is because I doubt
it is due to a bug of Emacs 22 and greater, not that of Gnus,
i.e., the change is no more than a workaround.  Actually it
doesn't happen in Emacs 21.4.  Could someone please look into it?

The problem is, in short, that the cursor in the Gnus summary
buffer jumps to a subject line that is not for the article being
displayed just after selecting the article by the `g' command, if
`scroll-margin' is a non-zero value (actually it is 3).  You may
need to have many articles in threads and to expand the summary
window to a certain height.

Thanks in advance.

> On Thu, Dec 20, 2007 at 3:47 AM, Katsumi Yamaoka <yamaoka@jpl.org> wrote:
>> (For the ding and the emacs-devel subscribers the whole original
>>  article is attached below.)
>>
>>>>>>> Yuan MEI wrote:
>>
>>> Gnus v5.13
>>> GNU Emacs 23.0.60.1 (i686-pc-linux-gnu, GTK+ Version 2.12.1)
>>>  of 2007-12-14 on may
>>> 200 aioe.org InterNetNews NNRP server INN 2.4.4 (20060818 snapshot) ready (posting ok).
>>
>>> As in screenshot
>>
>>> http://ymei.freeshell.org/1.png
>>
>>> nnml:m.gentoo-lists is a group with auto expiration (mail which is
>>> read is marked 'E' automatically).  It works well when I do the first
>>> 2 mails (press Enter on the first one, it is marked as 'E' and the
>>> cursor jumps to the second one, and press Enter on the second one, the
>>> second one is marked as 'E' and the cursor jumps to the third one).
>>> However, when I tried to do the same on the third one, the third one
>>> is marked as 'E' but the cursor didn't jump to the fourth one but
>>> jumped to the center of the buffer (the 7th mail).  More over, when I
>>> typed Enter again (on the 7th mail), as in
>>
>>> http://ymei.freeshell.org/2.png
>>
>>> the cursor stayed at the 7th mail, and the 7th mail is not marked as
>>> 'E'.
>>
>>> And I remember this didn't happen on the unicode branch CVS half a
>>> year ago.  I found this happen after I updated the emacs version of
>>> unicode branch.
>>
>>> Also, my .emacs contains
>>
>>> (setq scroll-step 1
>>>       scroll-margin 3)
>>
>>> I suspect that this is relevant to the problem, but it worked fine
>>> with the older version of CVS unicode branch.
>>
>>  Did it really work fine with the older Emacs Unicode-2?  Anyway,
>>  I was aware of this problem that happens in the summary buffer
>>  if `scroll-margin' is larger than zero.  AFAIK, it arises not
>>  only with Unicode-2 but also with the Emacs trunk and Emacs 22.1.
>>  Strangely, it is necessary to enlarge the summary window up to
>>  some size to reproduce the problem.  So, if you try this, also
>>  try enlarging the summary window or the whole frame height
>>  manually.  A workaround is here:
>>
>>  *** gnus-sum.el~        Sun Dec 16 21:51:27 2007
>>  --- gnus-sum.el Thu Dec 20 09:45:09 2007
>>  ***************
>>  *** 3005,3010 ****
>>  --- 3005,3014 ----
>>     (buffer-disable-undo)
>>     (setq buffer-read-only t            ;Disable modification
>>         show-trailing-whitespace nil)
>>  +   ;; FIXME: The value of `scroll-margin' larger than zero makes
>>  +   ;; the summary buffer's maneuvering malfunction.
>>  +   (unless (featurep 'xemacs)
>>  +     (set (make-local-variable 'scroll-margin) 0))
>>     (setq truncate-lines t)
>>     (setq selective-display t)
>>     (setq selective-display-ellipses t) ;Display `...'
>>
>>
>> (I'll be not so active in the net for this year-end and the
>>  year-beginning.  Sorry.)

> --
> Yuan MEI