Re: Control help- and Info-mode buffers from other buffers

[Juri Linkov]

> Maybe I'm missing something but I thought that Arthur proposition was
> more specific to "help" buffers.  So maybe following this pattern it
> could be something like this:
>
>   (defun scroll-other-help (&optional lines)
>     (interactive "P")
>     (with-selected-window (other-help-window)
>       (scroll-up-command n)))
>
> … but then, we'd have to imagine what 'other-help-window' is.

But scrolling commands are not specific to Help buffers.  For example,
scrolling commands that I miss the most to scroll another window are
'scroll-up-line' and 'scroll-down-line' (and 'recenter-other-window'
was added recently with an awkward keybinding 'M-C-S-l' for the lack
of better variants).  It would be unfortunate to add such wrappers
'scroll-down-line-other-window' and 'scroll-up-line-other-window'
that can't be bound to a keybinding by default.

However, for Help buffers the situation is slightly better
since we can bind Help-specific wrappers in the Help keymap, e.g.:

  'C-h 4 s' to run 'help-view-source' in the Help buffer.
  'C-h 4 i' to run 'help-goto-info' in the Help buffer.

These commands could use 'other-help-window' returning
the most recently displayed Help window buffer.