Re: [PATCH] emacs: jump: fix compile warning on emacs 23

[Austin Clements <aclements@csail.mit.edu>]

LGTM.  I'm a little surprised this is necessary, but whatever.

I think the eval-and-compile has to be top-level; it's certainly not
wrong for it to be top-level.  (I like the comment in the
eval-and-compile implementation: ";; Remember, it's magic.")

On Thu, 04 Sep 2014, Mark Walters <markwalters1009@gmail.com> wrote:
> notmuch-jump uses window-body-width which is not defined in emacs
> 23. To get around this it does
>
> (unless (fboundp 'window-body-width)
>   ;; Compatibility for Emacs pre-24
>   (defalias 'window-body-width 'window-width))
>
> This makes sure window-body-width is defined and all should be
> well. But it seems that the byte compiler does not realise that this
> guarantees that window-body-width will be defined and so, when
> compiling with emacs 23, it gives an error
>
> In end of data:
> notmuch-jump.el:172:1:Warning: the function `window-body-width' is not known to be defined.
>
> Domo and I came to following on irc: wrap the (unless (fboundp ...))
> inside eval-and-compile which ensures that both the test and the
> defalias (if needed) happen at both compile and load time.  This fixes
> the warning.
> ---
> I think Domo and I were both not completely sure whether the
> eval-and-compile should be inside or outside the (unless fboundp ..)
> or not (ie should it wrap the unless fboundp or just the defalias) nor
> whether it should be eval-and-compile or eval-when-compile.
>
> We think this is the right version but it would be good to have confirmation.
>
> I tested notmuch jump inside emacs 23 and 24 with notmuch-emacs
> compiled with emacs 23 or 24 (ie all four combinations) and it seemed to work.
>
> Best wishes
>
> Mark
>
>
>
>  emacs/notmuch-jump.el |    7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/emacs/notmuch-jump.el b/emacs/notmuch-jump.el
> index 5eb0949..2706b6c 100644
> --- a/emacs/notmuch-jump.el
> +++ b/emacs/notmuch-jump.el
> @@ -25,9 +25,10 @@
>  (require 'notmuch-lib)
>  (require 'notmuch-hello)
>  
> -(unless (fboundp 'window-body-width)
> -  ;; Compatibility for Emacs pre-24
> -  (defalias 'window-body-width 'window-width))
> +(eval-and-compile
> +  (unless (fboundp 'window-body-width)
> +    ;; Compatibility for Emacs pre-24
> +    (defalias 'window-body-width 'window-width)))
>  
>  ;;;###autoload
>  (defun notmuch-jump-search ()
> -- 
> 1.7.10.4
>
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