Re: [O] small koma bug

[Rasmus]

Hi Alan,

Alan Schmitt <address@hidden> writes:

> I think I have found a small bug in ox-koma-letter, but to fix it I
> would like your input.
>
> The bug: if "from-address" is not specified in the file, then it will be
> set unconditionally to the empty string, even if it is specified in an
> lco file.

OK.  AFAIK it's OK to leave out the fromaddress and fromname.

> The reason of the bug is as follows.
>
> To set up the from address, we call this:
>
> #+begin_src emacs-lisp
>    (let ((from-address (org-koma-letter--determine-to-and-from info 'from)))
>      (and from-address (format "\\setkomavar{fromaddress}{%s}\n" 
> from-address)))
> #+end_src

How about:

   (let ((from-address (org-koma-letter--determine-to-and-from info 'from)))
     (and (org-string-nw-p from-address) (format 
"\\setkomavar{fromaddress}{%s}\n" from-address)))

Or more explicitly

   (let ((from-address (org-koma-letter--determine-to-and-from info 'from)))
     (when (org-string-nw-p from-address) (format 
"\\setkomavar{fromaddress}{%s}\n" from-address)))

> This uses this function:
> #+begin_src emacs-lisp
> (defun org-koma-letter--determine-to-and-from (info key)
>   "Given INFO determine KEY for the letter.
> KEY should be `to' or `from'.
>
> `ox-koma-letter' allows two ways to specify TO and FROM.  If both
> are present return the preferred one as determined by
> `org-koma-letter-prefer-special-headings'."
>   (let ((option (plist-get info (if (eq key 'to) :to-address :from-address)))
>       (headline (org-koma-letter--get-tagged-contents key)))
>     (replace-regexp-in-string
>      "\n" "\\\\\\\\\n"
>      (org-trim
>       (or (if (plist-get info :special-headings) (or headline option)
>           (or option headline))
>         ;; Fallback values.
>         (if (eq key 'to) "\\mbox{}" org-koma-letter-from-address))))))
> #+end_src

I guess org-koma-letter-from-address can be left empty, but for
instance 'to must have a value different from the empty string to not
create a LaTeX error.  As I said above, quick testing suggest this is
not necessary for fromaddress.

> As the empty string is considered as "true", we apply the format
> function in the first code block.

See below.

> I would suggest to have "org-koma-letter-from-address" begin "nil" as
> default. My question is: is it an allowed value for a string?

You can use org-string-nw-p to test is S is only white-space.  When
Nicolas cleaned the file he made all (or most?) defaults into strings,
so let's stick with that.

Let me know if your happy with this.

—Rasmus

-- 
Summon the Mothership!