Re: Potential bug in the logic of rmail-select-summary

[martin rudalics <rudalics@gmx.at>]

 > A
 > more sophisticated config which is what I’d actually like to have
 > behaves a bit more weirdly:
 >
 > (setq
 >   display-buffer-alist
 >   '(((lambda (b _) (eq (with-current-buffer b major-mode) 'rmail-summary-mode))
 >      .
 >      (gk-display-buffer-for-rmail))))
 >
 > (defun gk-display-buffer-for-rmail (buffer _)
 >    (if (= (length (window-list)) 1)
 >        (display-buffer-in-direction buffer '((direction . left)))
 >      ;; If there are 1+ windows, use the top quarter of selected
 >      ;; window.
 >      (split-window-vertically (/ (window-height) 4))
 >      (switch-to-buffer buffer)))

While the 'switch-to-buffer' is not entirely kosher in this context
('display-buffer-in-direction' returns a window, 'switch-to-buffer' a
buffer) this function should do what you want when applied to some
arbitrary buffer.

However, it misses one important aspect of the original 'pop-to-buffer':
When a non-selected window showing the buffer already exists, it reuses
that window.  Your function doesn't do that and that causes the problems
you see when it is called multiple times in a row (as rmailsum.el does)
because it always tries to make a new window.

So I suggest you put a 'display-buffer-reuse-window' at the beginning of
'gk-display-buffer-for-rmail' and test how it behaves then.

martin