Re: View-quit in *Help* restores wrong window when display-buffer-reuse-frames is t

[martin rudalics <rudalics@gmx.at>]

 > I tried your patch. It fixes this problem and the problem in the
 > thread where you originally posted it. Is there anything else I should
 > test?

Thanks for testing.  So far I identified four groups of users:

(1) The one window one frame minimalist has `pop-up-frames' and
     `pop-up-windows' both and would like exiting view-mode to restore
     the window shown before.

(2) The one window per frame type has `pop-up-frames' non-nil and
     `pop-up-windows' nil and expects view-mode to pop up a new or reuse
     an existing frame.

(3) The at most two windows per frame user has `pop-up-windows' non-nil
     and `split-height-threshold' the default.  Such users expect
     view-mode to reuse any "other window" on the present frame
     regardless of its mode.

(4) The many windows per frame user has `pop-up-windows' non-nil and
     customized `split-height-threshold' appropriately.  Users in this
     group expect view-mode to reuse an existing window on the same frame
     iff it's a view-mode window.

My changes should set up information for exiting view mode correctly for
all of them.  The message printed when entering view-mode should be
correct with respect to how to scroll the help window and how to get rid
of its contents.  I have tried to test these but might have failed to
specify usage patterns correctly.  Maybe there's also another group of
users I failed to identify so far.

In addition my changes should cope with the following:

- Exiting view-mode should ideally (1) kill a window that has been
   popped up for view-mode purposes and (2) show the earlier contents of
   the window when it has been usurpated by view-mode.

- Exit information should not get overwritten when following links,
   hitting backward/forward buttons and the like (including Nick's
   `help-xref-go-forward').

- Something reasonable should be done when a user manually switches to a
   view-mode buffer and types `q' in that buffer.  Hard to get right for
   a type (2) user who intermittently displays some unrelated buffer in a
   view-mode window, manually switches back to the view-mode buffer, and
   types `q'.  What should I do here?  Kill the frame, display the other
   buffer and possibly lower the frame, iconify the frame, `bury-buffer',
   `quit-window', ...

- Is the `help-window-select' option useful?  The OP of the present
   thread had the usage pattern

   (progn
     (setq display-buffer-reuse-frames t)
     (describe-mode)
     (other-window 1)
     (View-quit)
   )

   With `help-window-select' non-nil, the `other-window' is not needed.

Getting some feedback in these areas would be very helpful.  Also, I'd
eventually want to get rid of all `print-help-return-message' instances
in the Elisp base including vhdl and python mode.  I have to check these
case by case though.  If I can get these right I'd finally like quitting
*info* and other temporary windows do something similar.