Re: po file charset via auto-coding-functions

[Kevin Ryde]

"Richard M. Stallman" <address@hidden> writes:
>
> I think it ALWAYS happens.  Every call to Finsert_file_contents will
> try to determine the coding system from the first 1k and last 3k of
> the file.  (Unless it already knows the coding system to use.)

I tried this (in my build of the cvs starting from -q -no-site-file),

        (debug-on-entry 'sgml-html-meta-auto-coding-function)
        (find-file "etc/NEWS")  ;; the emacs NEWS file

and got

        Debugger entered--entering a function:
        * sgml-html-meta-auto-coding-function(580713)
          byte-code("\212eb\210^H\211A^P@       !)\207" [funcs size] 2)
          find-auto-coding("/down/emacs/etc/NEWS" 580713)
          set-auto-coding("/down/emacs/etc/NEWS" 580713)
          insert-file-contents("/down/emacs/etc/NEWS" t)

ie. the size presented to the func (in just one call to it) is the
full 580kbytes (and the current-buffer has the full file contents).
So, like I say, I was unsure when this does or doesn't happen.

> To make it work reliably, therefore, I think the
> Vset_auto_coding_function function has to look at more of the file.
> If it is looking at a po file, it should do that.

Looking at more than 1k of the file will also be wanted for Project
Gutenberg texts.  They have about a ~1k blurb at the start before the
header information that has the coding system spec.