Re: [AUCTeX-devel] Interface of kpathsea file search

[David Kastrup]

Ralf Angeli <address@hidden> writes:

> Can anybody tell me what's the deal with the interface of
> `TeX-search-files-kpathsea'?  A few months ago I already added a
> FIXME comment about it being inconsistent with `TeX-search-files'
> and now I found a real bug related to it.
>
> When one tries to insert a \usepackage macro, `LaTeX-arg-usepackage'
> will let-bind `TeX-file-extensions' to '("sty").  Then (in
> `TeX-arg-input-file') `TeX-search-files' will be called with that
> value as argument for the EXTENSIONS parameter.  `TeX-search-files'
> will pass that value on to `TeX-search-files-kpathsea' also as the
> EXTENSIONS parameter.  But it is not used as a list of extensions.
> Rather its car is used as a format key for looking up some
> extensions mapped in `TeX-kpathsea-format-alist'.  Apart from that
> construction being completely insane, in this case it leads to a
> `kpsewhich -expand-path=' call (i.e. no argument for -expand-path is
> supplied) because there is no entry for "sty" extensions in
> `TeX-kpathsea-format-alist'.

We should probably check for this case.

> A failing kpsewhich call alone would not be so problematic but when
> this happens `TeX-kpathsea-path-delimiter' is set to nil and the
> kpathsea-based search will be disabled globally.
>
> I found all of this while trying to do a completion with TAB on
> "babel" after a `C-c RET usep TAB RET'.  The said thing is that the
> fact I noticed the problem means that `TeX-search-files' without the
> kpathsea-based search does not find babel.sty.  Duh.
>
> Okay, in order to fix the former bug I can add a
>     ("sty" "${TEXINPUTS}" '("sty"))
> to `TeX-kpathsea-format-alist',

More likely ${TEXINPUTS.latex}.

> but I am not really feeling comfortable with this because it is a
> misuse of the variable and the interface of
> `TeX-search-files-kpathsea'.

Actually, I can't see the misuse here.  Looks like the intended use to
me.

> Sooner or later we will have to do this right.

Well, that is the mantra of AUCTeX altogether.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum