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

[Katsumi Yamaoka]

(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 `...'

gnus-bug-73285.gz
Description: Original Article

(I'll be not so active in the net for this year-end and the
year-beginning.  Sorry.)